# Lakeside53's --361 muffler mod w/photos



## bri

Hi! could anyone tell me how to remove the muffler from a 361? I want to do some mods to it but do not want to damage it while trying to remove it.


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## Lakeside53

Two small covers in the front need to be removed. Deep inside are two 5mm bolts with T27 heads. The bottom screw is obvious and needs a washer (update on later saws) and to be secured with loctite 270.

I have a 361 muffler completely apart on my bench and I'm in the process of modifying it. Pictures and post to follow in a few days (just waiting for a part). I have figured out a simple way of adding a full-flow spark arrested port (not just a hole with a spark cover) without needing to uncrimp the muffler... but the internal pictures are very interesting. Big difference between this muffler and the older non-epa versions of the MS360.. and sadly a view of what is to come on the next generation of saws.


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## Stihl4life

Andy, what must you do to the muffler in order to "mod it"? I would like to mod the muffler on my 034 Super but dont know how.


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## fishhuntcutwood

Stihl4life said:


> Andy, what must you do to the muffler in order to "mod it"? I would like to mod the muffler on my 034 Super but dont know how.



Not to step on Andy's toes, but I'm up at 2AM, so I'll give you my .02-

Put holes in it. It's got a two piece muffler like an 036, 044, 046, 066, which are are very easy to do. Remove the front cover via the four T27 Torx screws and drill holes in it. Do a search on this site for "muffler mod" or something to that effect. There's various opinions on how much air to let through, so you can make up your own mind on that after reading. The general consensus is anywhere from 85%-125% of the exhaust port at the cylinder wall. You can add a spark arrestor as well if you like. Not a bad idea if you're going to be cutting anywhere other than your back yard in the dry season. 

Jeff


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## sawn_penn

Stihl4life said:


> Andy, what must you do to the muffler in order to "mod it"? I would like to mod the muffler on my 034 Super but dont know how.



Good timing! I'm modding my 034 muffler this weekend. My first challenge is that the previous owner welded the front cover onto the muffler - it makes getting at the internal screws a challenge!


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## Lakeside53

The postion of a second muffler port should be thought about. I don't want a port in the front of the muffler as it will get damaged when pressed up against a tree (the 361 muffler front is flush with the front of the saw already), must not interfere with the brake handle, push exhaust back to the operator, or onto hands when the saw is used on its side.

The issue of the spark arrester is a problem. If you need one for the area you live (or ANY western Forest Service land) simple drilling a hole and putting the screen over it is not a good solution. Sure it will arrest sparks, but will kill your exhaust flow over time. I'm a firm believer in having a screen not only for spark arresting, but to stop crud getting back into the muffler when the saw is NOT in use and subject to the muck of logging...

Screens are typically 40% obscuration (the wires) and tiny particles that cling immediately start reducing the output. If you look at the screen under a microscope even a "clean" screen that's been in use is reduced in though put considerably. Most good designs have a screen that is many times larger than the exhaust hole, and the screen is spaced back from the hole. Just making the exhaust hole larger isn't a good solution because it affects the tuning which will now vary as the screen blocks. It's a PITA to mod a muffler with a decent large replaceable screen with carriers, slots etc etc, but I do have a very simple off-the-shelf solution which you'll see in a few days.

The 361 and 036 (just two examples; there are many more) have a large screen and a small exhaust. 

036 screen: 31x25mm = 775 sq mm. Exhaust hole (round plus slot) area - 113 sq mm... 

361 screen: 36 x16 = 576 sq mm. Exhaust hole area - 63.6 sq mm (Damn, that's small... How do they get such good performance from 9mm round exit?)

Exhaust area AT the cylinder wall of the 036 is 327 sq mm. The 361 looks similar, but I need to get inside to measure it to be sure.

So.. the 85% number that gets batted around... maybe for some race machine, but for a woods machine, I don't think you need it even close to this. On the 036, this would be the same a having a 20mm round hole in the muffler. At some point all you get is more noise and you run out of the carbs ability to deliver enough gas!

On the 361, I'm going to start by taking the the output area from 64 sqmm to about 142sq mm TOTAL (leaving the existing port). I'm going to mod a second muffler that has an output area of 217sqmm, and compare. I'm betting there will be little to no difference in cut speed between the two modded mufflers.


For now, here's the pictures of the inside of the 361 muffler. 



This is the entire muffler. Note the two plugs in the front. These are rusted in to the point where they need to be drilled out. PITA. The updated plug is a nice three-flanged device that is much easier to remove.









Opening the muffler... lever up up the heated crimp with a screw driver..






This is the inside looking towards the front. The cage and spark arrester assembly is all stainless. The tube (bottom left) intersects with the hole at the back of the muffler to exit. It's 9mm (inside) diameter.








Looking to the back of the muffler:









What about the internal cage? Forget it. It has plenty of area - over 470 sq mm of holes already!


If you don't want a spark arrester, the solution is easy - just uncrimp the muffler, chop off the internal pipe and grind away the inside edge of the output hole to the size you want.


My solution will allow a removable spark arrester, no material flow restriction over time, no need to uncrimp the muffler and about 20 minutes work (if that). Give me a few days...


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## jack-the-ripper

I called WALKERS SAW SHOP about modding the muffler my 660, after talking to the "muffler mod man" , he told me basically the same thing Jeff said. Drill 2, 5/16" holes in the end of the baffle box. Then enlarge the exhaust hole in the muffler a little bit. To take it a step further, he gave me a part number for a front cover with a exhaust port in it. I didn't want the baffle in there so I went to my friends shop and ground the most of it out instead of drilling. Didn't order the cover though. Think I will just have my friend braze the pipes on later. Sure helped but, the dual port is the best bet. IMHO. Reason being when Walkers did my 372, it really came to life. Here are a few of Walkers mufflers.


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## Lakeside53

Stihl4life said:


> Andy, what must you do to the muffler in order to "mod it"? I would like to mod the muffler on my 034 Super but dont know how.




That one is pretty easy.. but not optimal. Take off the front cover, take out the screen, and drill a few (I'd use 3) 5/16 holes in the raised section on the *inside*. Don't drill though to the outside. Clean out the metal bits!. I assume you have the version with a series of holes at right angels to the cover? Lever up the external guard and punch the internal deflector out somewhat using your newly drilled holes for access. Put the screen back in.

retune your carb!


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## Lakeside53

jack-the-ripper said:


> I called WALKERS SAW SHOP about modding the muffler my 660, after talking to the "muffler mod man" , he told me basically the same thing Jeff said. Drill 2, 5/16" holes in the end of the baffle box. Then enlarge the exhaust hole in the muffler a little bit. To take it a step further, he gave me a part number for a front cover with a exhaust port in it. I didn't want the baffle in there so I went to my friends shop and ground the most of it out instead of drilling. Didn't order the cover though. Think I will just have my friend braze the pipes on later. Sure helped but, the dual port is the best bet. IMHO. Reason being when Walkers did my 372, it really came to life. Here are a few of Walkers mufflers.




I just ignored the existing hole on my 066 and added the factory dual port. It's SO much larger than the original that modding the original makes no difference. I published the measurements of the various original exhaust sizes and the dimensions of the factory dual port some time back. 


Here's an extract from the orginal thread:

_


The standard muffler on a USA post 1998 066 or MS660 has an exit hole of 0.43 inch diameter. Prior to 1998, this was 0.63 inch. In 1998 they also made changes to the cylinder porting to reduce emissions (not sure what they did).

The USA Magnum muffler front has a internal rectangular hole (with rounded ends) of 1/2 x 1 9/16 inches feeding an external slot of 5/16 x 1 1/2. 


So, area of outlet:

Prior 1998 : 0.311 square inches
Post 1998 : 0.145 square inches

Add a Magnum muffler front to either : add 0.469 inches... (and it might be a tad more than this).

Yes, the saw winds up pretty good with a magnum front and you have to remove and reset the limiter caps to richen the carb. 

The internal box with all the smaller holes in it is the same for all the 066 mufflers.

That Post 1998 size sure seems puny in comparison to the other numbers!

NOTE: anyone messing with an earlier 066 muffler needs to make sure they have a main carb jet of at least .72mm. The "red eye" 066's had a main jet of .66mm (because the ignition limited the max rpm). Stihl published a tech note to say that using the .66 jet and turning up the rpm will result in piston seizure... as the saw couldn't get enough gas at high rpm._



If you want a screen, the "factory" option from 1995 is the way to go on the 660.. and if you have a cage, yes, drill out the end a little.


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## Lakeside53

Ax-man said:


> From the looks of that muffler he won't have to richen it after the muffler mod. Thatt saw is running plenty rich
> 
> Larry




Not so sure... I look in the exit pipe and at the "hot areas". 

The soot in the back was from my mapp gas buring up old crap, and the "wet look" is from my bucket of water

However...

That 361 muffler was from a saw used in a lumber yard for cutting beams to length for the customers. 100+ starts per day, never runs for more than 30 seconds... These guys are really hard on their saws. !


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## Stihl4life

Ok guys, thanks for the advice. My only question is this: I am a motorcycle guy, and when you would adjust the carb, you would re-jet it. Meaning buying new jets. What would i want to do to the carb after drilling some holes in my muffler? :greenchainsaw:


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## Lakeside53

Stihl4life said:


> Ok guys, thanks for the advice. My only question is this: I am a motorcycle guy, and when you would adjust the carb, you would re-jet it. Meaning buying new jets. What would i want to do to the carb after drilling some holes in my muffler? :greenchainsaw:




On your 034 super, assuming it has the C3A-S4 carb or similar, you won't have to re-jet it. Just adjust the H screw richer (counter-clockwise). You might need to adjust the L screw also for stable idle. Don't over-do the muffler mod - you can always add more area later and it's easier than putting it back!


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## Stihl4life

Thanks! I drilled thee 1\4" holes in it and it will pull a 28" bar through hard maple no problem!


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## Stihl4life

How do i mod the muffler on a Husqvarna 371XP? My friend has one and he asked me how to do it.


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## sawn_penn

sawn_penn said:


> Good timing! I'm modding my 034 muffler this weekend. My first challenge is that the previous owner welded the front cover onto the muffler - it makes getting at the internal screws a challenge!



OK... I got the muffler off, which was quite a trick given that the torx screws were inside the welded-shut muffler. 

So I now had a muffler with two screws rattling inside it. I tried to cut the welds out with a dremel, but I made a mess of the job. I ended up cutting the front off the muffler with a 4" angle grinder.

I left the cage alone, and welded a new front on the muffler. Two 3/8 holes and a couple of short pipes to bring the exhaust forward.

A quick retune and everything is running great. 20% faster and 100% louder!


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## 04ultra

Hows that...I made it a little lighter


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## Freakingstang

Stihl4life said:


> How do i mod the muffler on a Husqvarna 371XP? My friend has one and he asked me how to do it.




here's a couple pics of ways to do it on a 365, 371, 372, or 385 


















-Steve


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## Lakeside53

sawn_penn said:


> OK... I got the muffler off, which was quite a trick given that the torx screws were inside the welded-shut muffler.
> 
> So I now had a muffler with two screws rattling inside it. I tried to cut the welds out with a dremel, but I made a mess of the job. I ended up cutting the front off the muffler with a 4" angle grinder.
> 
> I left the cage alone, and welded a new front on the muffler. Two 3/8 holes and a couple of short pipes to bring the exhaust forward.
> 
> A quick retune and everything is running great. 20% faster and 100% louder!




"rustic", and you can brand "2-hole" into all you rounds


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## Lakeside53

*361 muffler mod with optional spark arrester*

Continuing from the earlier post in this thread showing the inside of the 361 muffler and spark arrester issues.


The easiest solution to adding a port is simple to drill a hole and insert a tube. Covering this with a screen is a poor choice as the surface area of the screen is small. Stihl solved this problem on the BR400/420/340/380 series of blowers (as far back as 1992 on the BR 400) by inserting a tube of screen material into the pipe. It folds back over the pipe and is secured by a clip. The screen is many times the area of the outlet, so flow restriction even with some blockage is minimal. 

This can be used on any almost any saw where you need a spark arrester and are adding a port (so long as you have room inside). You can of course choose not to fit it, but so long as the tube is the correct dimension, you have the option of putting it back in!






There are two basic sizes available: One fits over a 14mm OD (roughly 1/2 inch ID) pipe and the othe over a 16mm OD thin wall pipe. The picture shows the 14mm version. I'll have the 16mm version is a day or so and will likely use this as the pipe is thin wall 9/16 ID tube will work and is easier to find (for me).

Part numbers: 

14mm version (BR420 etc blower)
Screen - 4203 141 9005 $5.56
Clip - 4203 141 6600 $2.00

16mm version (TS 400 Cut-off saw)
Screen - 4223 141 9000 $4.25
Clip - 4223 141 6600 $3.25


I did not need to tear the muffler apart to do this modification. The only reason I did was to educate myself on the internals and space constraints. In the future, it's just drill a hole at 45 degrees, grind the bottom of a short tube at 45 (so the screen has maximum area inside the muffer), and braze it on. For those of you intimidated by the thought of brazing, it is dead easy and can be done with Mapp gas available at your local hardware store.

The easiest way to drill a big hole at 45 degrees in thin metal is to use a uni-bit or one of the cheaper clones. They look like this :







Here's the muffler back together (heated the crimp area "red" and crimped it back together):







This is what the 14mm screen looks like inside the muffler. The 16mm is longer.







Here's the completed muffler on the saw. The factory spark arrester and exhaust port are unmodified. Heck you could even put it back to "factory" by plugging the new port! 

One nice coat of matt exhaust paint and a quick bake (450F for an hour in the convection oven!) and it's one tough coating and ready for work. Hmmm, looks like factory stock to me.








Questions? Improvements?


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## GASoline71

That looks good Andy.... 

How much would you charge for that to be done?

I wanna open up my 361 muffler, but I wanna keep it legal here in our home state.

Gary


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## Lakeside53

GASoline71 said:


> That looks good Andy....
> 
> How much would you charge for that to be done?
> 
> I wanna open up my 361 muffler, but I wanna keep it legal here in our home state.
> 
> Gary




Just to be clear... it's legal with respect to a Spark arrester, but not to EPA or CARB... But I think I know what you mean...:hmm3grin2orange: 

As to the other question, not sure... first I need to find a good supply of the right sized tube. The last one I turned down in a lathe, and I'm not doing that for every muffler! I'm figuring that the 16mm option will be much easier but I won't know for a few days.


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## GASoline71

Lakeside53 said:


> Just to be clear... it's legal with respect to a Spark arrester, but not to EPA or CARB... But I think I know what you mean...:hmm3grin2orange:



Yup... that's the ticket! :biggrinbounce2: 
Gary


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## sawn_penn

Lakeside53 said:


> "rustic", and you can brand "2-hole" into all you rounds



This is a 034 with a broken crankcase (splinted with angle iron and rivets).

It is well on it's way to being a "hillbilly" saw.

... as for the two pipes sticking forward out of my muffler, I had the same spark arrestor idea you had.


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## Lakeside53

sawn_penn said:


> This is a 034 with a broken crankcase (splinted with angle iron and rivets).
> 
> It is well on it's way to being a "hillbilly" saw.
> 
> ... as for the two pipes sticking forward out of my muffler, I had the same spark arrestor idea you had.



If you are going to use the Stihl spark arresters, you do need to get the pipe size figured first. The mesh is surprisingly tough and difficult to "mash" into anything other than what it was designed for. I turned (on a lathe) a 1/2 inch sleeve (about 12.8mm ID) until it was 14.3mm on the outside... Easier than driving 25 miles to get the right tube, but... I'm just going to get the right 5/8 (15.8mm) or .630 OD tube (16mm) and use the 16mm arrester/clip. 6 feet of it will keep me in muffler mod supplies for a lifetime.

The good thing about figuring this out is that it applies to any mid-size saw, not just Stihl. I thought about 2 14mm tubes on the right hand side of the 361 muffler (there is room), but I just don't need the outlet area. One 16mm will be plenty. Maybe on 80cc class or above I can add multiples.

Now to figure out what to do with my 088! (actually, that one is a no brainer...) and it's already so damn loud no one will notice if it gets louder


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## sawn_penn

Lakeside53 said:


> If you are going to use the Stihl spark arresters, you do need to get the pipe size figured first. The mesh is surprisingly tough and difficult to "mash" into anything other than what it was designed for.



I have some other mesh, and I was planning to use hose clamps to hold it in place.


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## Greg Lees

GASoline71 said:


> That looks good Andy....
> 
> How much would you charge for that to be done?
> 
> I wanna open up my 361 muffler, but I wanna keep it legal here in our home state.
> 
> Gary



Ditto for me too, Andy....

Greg


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## fishhuntcutwood

Nicely done Andy. Looking forward to hearing about the 16 mm version.


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## Lakeside53

*16mm version done...*

Here's the 16mm (od) version. This is done without uncrimping the muffler.

I never did get around to getting any 5/8 OD and 9/16 ID pipe. I just took a length of 3/8 black pipe, bored out the the center to 37/64 (you can use 9/16th... my bit was messed up), and turned the outside to 5/8 / 16mm. Easy to do in a lathe, and as you only need a 3/4 inch length, you could probably drill it in a drill press then take a file to the outside (while in the press and spinning ) and file it down to 16mm.

Place the pipe cut to length and with a 45 degree base (3/4 inch longest measurement) on the Muffler and scratch around it. This will give you a guide for drilling/filing. This is so you *Do NOT make the hole too big or the pipe will slip inside and you will have to uncrimp the muffler to get it out! SLIGHTLY SMALLER IS BETTER!*













Insert the Pipe into the hole. I put a set of vice grips on the pipe, hooked the right side end under the muffler metal, and let the weight of the grips hold it all in place so I could braze it without the pipe moving.






Brazing completed. Just a quick wire brush and a pick to remove any old flux, and ready for painting and baking. *Now is the time to CLEAN OUT all the filings and junk you put in the muffler*. Shake it, blow air though it and do whatever, but metal filings are not a good thing to have in the muffler... 







Finished muffler and 16mm fire screen inserted.







So, how does it perform? Cuts good, gets up to rpm real quick, and more most importantly, it doesn't sounds like a strangled chicken or sewing machine any more!!! I did need to reset both the L and H on the carb to slightly richer. I don't have any measured cut times yet, but it definitely came alive. I the 16mm any better than the 14mm version? Hard to say... but it feels right at 16mm so that where it will stay.


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## Lakeside53

One more - on the saw:


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## wagonwheeler

Extremely nice work Lake! I've got the screen and clip, just need to source the pipe...or a lathe...

Chaser


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## Lakeside53

wagonwheeler said:


> Extremely nice work Lake! I've got the screen and clip, just need to source the pipe...or a lathe...
> 
> Chaser




It's coming with that other part you wanted


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## Four Paws

*DIY Muffler Mod*

Well, maybe the moderators can sticky this thread, or something - I hope it can grow into a good bit of information, sort of like a reference guide, that folks can use to find info on modding their mufflers, rather than seeing a new post in the forum every other day.

*YOU NEED TO MOD YOUR MUFFLER!​*See this--> http://www.palmtreeservices.com.au/video/33cchomelite.wmv

A basic muffler mod "opens up" the exhaust system to allow more gasses to flow out of the engine with less restriction. This is accomplished with a bigger 'hole' in the muffler. 

SO, What do you need to mod your muffler? A little time, a little patience, a few tools, and a little skill.

You will need the following tools:

Drill and drill bits - up to 1/2" for most smaller saws, up to 3/4" for bigger saws.

A welder (MIG/TIG) or a set of Oxy/Act torches and proper filler material - yours or access to your friends, it doesn't matter, but you shouldn't be trying to JB weld your muffler together!

Dremel tool/files/die grinder - Just something to clean up the burrs on your steel pieces.

Hacksaw and tin snips - depending on the style of mod you plan to do, these will come in handy and at times, be necessary.

An assortment of steel - 1/2" - 3/4" tube, 18 ga. sheet, spark arrestor screen.

Mods are accomplished MANY different ways. But, the most basic modification is to drill a hole in your muffler. This increases the area your exhaust has to exit the muffler - allowing the saw to breathe better, run cooler, and perform better. Holes should be drilled in a convenient location where the exhaust won't blow back at the saw operator, burn plastic pieces on the saw, start a forest fire, etc. "Measure twice, cut once" and make sure you know what you want before you start hacking away at your muffler. The surface area of the new exhaust hole should be about 80 - 85% of the exhaust port surface area at the cylinder. Taking your muffler too far, and making too big an exhaust hole will actually decrease your saws performance!

Some saws have a 2 piece muffler. These can be disassembled and the baffles inside can be modified or removed. Some Stihl saws can also be equipped with a factory dual port muffler cover which usually makes any additional muffler mods unecessary for most folks. Saws without a 2 piece muffler cover can be cut open and gutted - however this is rather involved and requires more skill to put them back together (best accomplished with a TIG welder). 

After you have your holes drilled and baffles modified, you need to "finish" your muffler. Finishing it can be accomplished many ways - the "looks" of the mod should be pleasing to you, but the bottom line is, the muffler MUST function well to give the desired performance. ALWAYS install a spark arrestor screen over the new hole you have drilled in your muffler! Based on how far you have taken your muffler, it's initial design, and your patience/craftsmanship skills, will determine how you finish it. I have included some picture of muffler mods below.

Some folks drill a hole, and use a washer with a screen behind it, welded to the muffler to "finish" it as seen below on rahtreelimbs Husky 359.






On a muffler mod I did to my Shidaiwa 577, I removed the factory deflector, and fabricated a new one out of 18ga sheetmetal, and 1/2" tube. My new piece replaces the factory deflector, is bolted to the muffler, and has a spark arrestor screen behind it. The internal baffles in the factory muffler were very free flowing, and I did not have to modify them.











I encourage others to add pertinent information and pictures to this thread with descriptions of their work, what saw it was on, etc. Please do not use this thread for chit-chat.


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## rahtreelimbs

Nice Mod there Four Paws!!!

Who did that 359???:biggrinbounce2:


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## SWE#Kipp

This one I made for my 372xpg ,,, (walkerz style)
It's two 16mm pipes "brazed" 























/Kristoffer


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## rahtreelimbs

Even a saw as new as the Stihl 441 can be easily muffler modded!!!


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## Canyon Angler

Are there any drawbacks or downsides to opening up the exhausts on these saws?

I know that if you run a 4-stroke with just open headers, you can end up burning the valves / valve seats ... is there anything like that we need to watch out for on these 2-strokes? 

Seems like the engineers would have figured out everything already on their own, and if the saw ran better with a less restrictive exhaust, they would have sent it out that way from the factory ... no?


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## Four Paws

Canyon Angler said:


> Are there any drawbacks or downsides to opening up the exhausts on these saws?
> 
> I know that if you run a 4-stroke with just open headers, you can end up burning the valves / valve seats ... is there anything like that we need to watch out for on these 2-strokes?



Read my first post - all the combined surface area of all the holes in your muffler, should not exceed 80-85% of the of the surface area of the exhaust port at the piston surface.



Canyon Angler said:


> Seems like the engineers would have figured out everything already on their own, and if the saw ran better with a less restrictive exhaust, they would have sent it out that way from the factory ... no?



No, the EPA has to butt their head in and mandate that saws be detuned to meet epa requirements - all this means is, rev limiters, restrictive intake and exhaust. Try breathing through a straw...just because you can, doesn't mean it is good or comfortable!


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## SWE#Kipp

Four Paws do you think my outlet area is to big for a 372xpg ????


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## Canyon Angler

Four Paws said:


> No, the EPA has to butt their head in and



Oh, I gotcha – :bang: :bang: :bang: Probably OSHA and everybody else in the alphabet soup, too. "Protecting us from ourselves." 

Thank God for bureaucrats! :greenchainsaw:


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## sawinredneck

Nice work, and better idea Fourpaws!!!! This is the thread on my ms192t.

http://server1.arboristsite.com/showthread.php?t=33917&highlight=192t+muffler+demystified




Andy


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## Rspike

*359 , 346xp , 346xp , 372xp*

<img src="http://i9.photobucket.com/albums/a97/Roospike/FOURM/A1.jpg"> <img src="http://i9.photobucket.com/albums/a97/Roospike/FOURM/A2.jpg"> <img src="http://i9.photobucket.com/albums/a97/Roospike/FOURM/A3.jpg"> <img src="http://i9.photobucket.com/albums/a97/Roospike/FOURM/A4.jpg"> <img src="http://i9.photobucket.com/albums/a97/Roospike/FOURM/A5.jpg">


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## rahtreelimbs

That *bracket/screen method* is a great way to do muffler mods!!!


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## Haywire Haywood

I read somewhere online recently that you could braze with MAPP gas. So I bought a bottle of that and a general purpose 1/8" brazing rod with the flux coating. I had my doubts about it getting hot enough, so the first thing I did was see if it would melt the rod. It melted the flux off and that was all it did. $10 gone to waste on that effort.

Ian


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## NORTHERN NYer

Here is what I did on my 359.

http://www.arboristsite.com/attachment.php?attachmentid=36137&d=1152930018
http://www.arboristsite.com/attachment.php?attachmentid=36140&d=1152930823


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## Canyon Angler

Today, going off of Two Paws's post above, I took a drill bit about 5/32" and drilled two holes behind the screen and two holes in the cover that goes over the screen on the muffler of my MS-310 and all I can say is WOW. It seems to run MUCH faster and breathe a lot freer, and it SEEMS to have more power. Louder, too!

There's not a chance that these mods would allow my saw to OVER-rev, is there? I know that on 2-stroke outboard engines, if you open the throttle under a no-load condition, you can get what they call a "runaway" situation (kind of like a "cook off" with a machine gun, I guess) where it can be difficult to throttle the thing back down. Any chance of anything like that happening with a saw? No chance of damage, is there?

Thanks,

CA


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## rahtreelimbs

Does this mod hit when you buck big wood???


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## Haywire Haywood

Canyon Angler said:


> No chance of damage, is there?



In a word... Yes.. That is if you won't retune the carb afterward. From my understanding, you will be running too lean if you don't, and that is bad juju.

Ian


----------



## NORTHERN NYer

> [Does this mod hit when you buck big wood???/QUOTE]
> That was is one of the concerns I have with it, something I realized after the fact. It is behind the dogs some, and I havent had it hit yet. I have bucked with it a few times since the mod but nothing really big yet for the dogs to really bite in. I do most of my cutting in the winter time for next years fire wood and most of it is on a pile, so I guess I will find out more then. If I have to I can cut it back some more. I really like the bracket screen method, I wish the bracket on the 359 was a little higher to go with the exhaust outlet fully in the bracket. It looks really clean that way. Anyone have the muffler crack or split from vibration in a newly cut opening with out the added strength of a washer or something welded on?
> An off the topic question, sorry.How do I repost a pic that I have posted on another thread with out adding the link? It gave me an error message saying I have already posted the pic on another post even when I change the name of the pic.


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## Kneejerk Bombas

Go to that picture, copy the URL, then when your posting, paste the URL in to the screen you get when you click the "insert image" or "insert link" buttons.


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## Four Paws

Here is a link to a very nicely done Stihl 361 muffler mod, with good information and a nice write-up included as well!

http://www.arboristsite.com/showthread.php?t=33528&page=2


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## oneadam12

hey Lake, was the extra tube in the side of the muffler the only "extra" hole you drilled in the muffler in the above link?


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## Lakeside53

oneadam12 said:


> hey Lake, was the extra tube in the side of the muffler the only "extra" hole you drilled in the muffler in the above link?




Yes. Just the one. The factory outlet stays as is


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## manual

*Internal cage*

Wouldn't you think that the internal cage would slow down the air flow.
The air still has to race down the walls and find a hole to excape.
I'm thinking in doing so it would also create an venturey vacuum effect with some of the holes.


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## Lakeside53

Maybe, but the area of all the holes is is so large it doesn't really matter (over 470 sq. mm). Easier to leave it in place. I figure you get "most" (just a guess!) of what you are looking for with a simple mod, so why go crazy on the rest? 

If you don't want a spark arrester (I do) and want to go though the task of opening muffler, then just remove all the internals and open the factory port - it is is in the best position for the hot gas flow when cutting. I'm not sure the results will be materially different to what I did with the additional front port. If you're going to port the cylinders etc, then maybe...


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## CaseyForrest

Ive got one of Lakes modified mufflers on my 361.

You know when you first fire up your saw, and it smokes a bit? I was watching it the first time I fired it up, and cant believe how much exhaust comes out the pipe, as opposed to the OE port. 

Seems its in a good location, and well sized.

Good job Lake!!!


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## Lakeside53

You do need to watch your hands though - exhaust bouncing back from a big fir I was blocking close to the ground melted my glove... 

When installing your port. Make sure it's angled forward as much as possible (away from the hands) and set back from the front so it can't be blocked by bark. And yes, you can catch bark on fire from the hot gases!.


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## manual

No No I want to keep the arresters too.
Thinking of making the ports wider. so I want to be able to push the gasses out. 
Maybe I am digging to deep in thought.


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## Lakeside53

The quad transfer ports are already really wide on the 361... It's not anything like the 036. Be careful.. a new piston/cyinder costs $300..


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## Four Paws

*Husky 232R Brushcutter*

Well, not a chainsaw muffler mod, but a muffler mod none-the-less.

Here is the stock muffler on my Husqvarna 232R Brushcutter before starting the project. The hole on the left is an additional hole I added immediately after buying it. 






This next photo shows the muffler apart. I used a 00 brazing tip on my oxy/acetylene torch to heat the seam on the muffler red-hot, and pryed up the metal with a screwdriver to separate the two halves of the muffler. The piece on the right is the catalyst part of the E-tech catalytic convertor muffler. My brushcutter ran VERY HOT with this muffler. Same as the 359 chainsaws.






Next, I cut a baffle out of 20ga sheetmetal. I used tin snips, cleaned it up with a grinder and hand files. I traced out the 3 holes of the bushings (keeps the muffler from squashing when tightened on the machine) and drilled them out. I then used a punch to mark out where I wanted to drill holes in the baffle. This new baffle I made has a LOT more surface area than the old catalyst baffle, but will still provide back pressure which the engine needs.






Finally, I assembled the muffler halves back together, making sure everything lined up and all necessary parts fit up properly. Heat it back up with the torch, crimped it with some pliers. After it cooled, I wire brushed it, cleaned it off and gave it a nice coat of flat black BBQ paint. All ready to go back on the machine! 






Don't forget to adjust your carburetor!


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## manual

Lakeside53 said:


> One more - on the saw:



Got a P/N on those caps ? Thanks for the help.


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## Lakeside53

If you're talking about the muffler screw plugs: 1135 145 9001


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## manual

Yes Sir thank you.
I should have the Sthil Dealer look the parts up himself But I like the way he looks at me when I tell him the part numbers. "It's Priceless"


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## Lakeside53

Yes, its great as dealer also - if you give me the wrong number, you're stuck with it :hmm3grin2orange:


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## JUDGE1162

First this should be a sticky (the Moderators show take note this is a great post!!!!!!!!!!!!!!!!!!)


Second for us not so handy are there companies or individuals that do this type of work? I am very interested in doing this to my saw but I do not weld, is they a way that does not include welding?

I know I should have paid more attention in shop class:bang: :bang: :bang:


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## computeruser

Good post. Definitely a stickey. And when I finally get my Chainsaw FAQ website put together, I'll be asking for permission to borrow some of these pics and write-ups!


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## JUDGE1162

I was researching on several web-site and came across this 

"The 455 is a new emission compliant stratocharged design and may not respond to the standard muffler mods. The 455 has a horizontally split crankcase. There are two intake ports and an extra transfer port. The second ports draw air only into the combustion chamber to allow a complete burn of that 30 percent you mention.I believe the muffler is also equipped with a cat which limits mods.The carb may also be fixed jet"

Is this true that the 455 Rancher is not modifiable?


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## computeruser

JUDGE1162 said:


> I was researching on several web-site and came across this
> 
> "The 455 is a new emission compliant stratocharged design and may not respond to the standard muffler mods. The 455 has a horizontally split crankcase. There are two intake ports and an extra transfer port. The second ports draw air only into the combustion chamber to allow a complete burn of that 30 percent you mention.I believe the muffler is also equipped with a cat which limits mods.The carb may also be fixed jet"
> 
> Is this true that the 455 Rancher is not modifiable?



Where did you find this info?

Not sure about the carb issue, but cats are regularly removed from the muffler in the course of modifications.


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## JUDGE1162

Would hate to cross post forums names, I have checked out quite a few, the one I found it on was a smaller site, which did reffrence this Site as the place to go for some answers.

It seems like people have done mods to 455 ranchers before but no sure if it does more harm than good.


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## vegaome

Howdy folks.

I just could not resist drilling some hole in my muffler after reading all this muffler mod info. I have two Echo CS-510 chainsaws. I bought them both used from different people about eight months apart. 

Knowing what I know now I probably would of passed on the first one as the plastic near the muffler was burnt some. I did not pull the muffler to look at the cyclinder, piston and rings. I just cut a few logs and and bought it. It is scorched a little after looking but still pulls 148 cold on the compression test. As this is now my back up saw I thought I will fiddle with it.

I pulled the limiter caps and now drilled ten 1/8 inch holes in the muffler. Five on each side of the front. I will try to adjust the carb in the moring and maybe cut some wood. I used it all last year to cut my wood. Not sure if it was good to drill a bunch of little ones verses a big one but we will see. 

I have a friend with an oxy-accetaline torch and some coat hangers if I have to reverse it. 

Since the saw has been run pretty hot before and there is some scoring do you think it was safe to mod the muffler? 


Any thoughts on ten little holes verses a couple of bigs ones?

Since I don't have any screen I thought it would help keep debre from getting in. I remember as a kid an old lawn mower we had with a muffler with many holes in it. Of course they were in a more symetrical pattern than mine. I just used my old stanley turn by hand crank drill (you know a WV cordless drill). 

My second saw is in real good shape so I wont experiment with it, for now. Thanks all and have a good evening.

v/r
Mike


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## Lakeside53

computeruser said:


> Where did you find this info?
> 
> Not sure about the carb issue, but cats are regularly removed from the muffler in the course of modifications.



Why would they need a CAT if the 455 is a stratocharged design?? Something isn't right... and yes, if it is a true stratocharge, then it won't respond well to the muffer mods of old...


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## JUDGE1162

Lakeside53 said:


> Why would they need a CAT if the 455 is a stratocharged design?? Something isn't right... and yes, if it is a true stratocharge, then it won't respond well to the muffer mods of old...




Please explain to a 2 stroke newbie, why if it is a true stratocharge, then it won't respond well to the muffler mods of old?

From my understanding and please correct me if I am wrong!!!!!!!! 

All stratocharged mean is there is an extra "cycle" where air with no gas/oil mix is pushed into the cylinder to push out the exhaust gas to cut down on "blow by" wasted extra fuel/oil being pushed out with the exhaust which happens in a standard 2 cycle motor.

I know it causes lower max rpms as the extra cycle of air with no fuel takes time to happen. But I am not sure why a standard muffler mod would not work.


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## timberwolf

> Any thoughts on ten little holes verses a couple of bigs ones?



10 small holes of the same area as one big hole will flow less because restrition to flow is highest along the edge of an orfice, more small holes has a longer edge than one big hole of the same area.

However scavenging can be affected by too big of a single direct opening allowing fresh charge to escape the confines of the muffler, so in a way smaller openings cold be incorporated to minimize losses, but it is going to be complicated as how much of the fresh charge gets out into the muffler and how much gets sucked back into the motor depends essentially on the scavenging efficiency and design of the saw, how dilluted the escaping fresh charge becomes after entering the muffler depends on the shape and design of the muffler. Realy need to look at the flow and mixing of charge and exhaust in the muffler. The more the fresh charge dillutes into the exhaust, the less can be recouped. Run a saw with no muffler at all, and it has less power than with a typical muffler as too much charge is being lost to the suroundings and not recovered during scavenging.

The area of 10 small holes will need to have a greater area than one big hole to give the same flow and back pressure.


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## twoodward15

So, I've got this McCullock timber bear 55cc saw that I use on my home made CSM. It's under powered for the job but runs good and gets it done. I didn't pay anything for this saw, so it won't be much of a loss if this doesn't work. Should I do it? I need more power. Anyone have a guess as to how much more power I will get if I do this mod? Where do I get this spark arrester screen?


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## timberwolf

Older Pre EPA saws pick up less as a rule because the exhaust are big to start with.

A new cat style muffler may gain 25-30% with a stock chain, 40% with a race chain. How much you gain depends on your chain, opened muffler will change the RPM and torque. If your chain is right you will get more bang for your buck.


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## twoodward15

since I am new to this and wanting to do the muffler mod, can I simply just drill another hole in my muffler? I read the first post and the OP (thanks for the info by the way, I've been wanting to do this for a while now) says that it is the simplist way to get it done. Do I need to open up my muffler? I've never had the muffler off this saw, so I don't know what it looks like. Where do I get the screen from? Back to the horsepower thing. Are we talking .1 h.p. or .5 h.p. or more? Any guess would be fine, I'm just trying to grasp some reality here for my own estimations. Thanks for the help. I'll keep asking questions I'm sure. I am going to try to get one saw done tomorrow and I also have a homolite like the one in the movie that I am going to do wednesday if all works out.


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## SRT-Tech

would it be worthwhile doing a mod on my Husky 61 muffler? Its a 2 piece, with removable baffle plate/screen.


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## JUDGE1162

YEAH, that would be an easy mod, you might not get as much gain as on a new saw with all the EPA crap but you should get some improvement with little effort on a two piece carb.


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## SRT-Tech

there is (if i rememebr correctly, still a bit foggy) about ten holes in the baffle, with mesh covering them. My plan is to remove the mesh from the ten holes, which will open up the flow a bit , and then make a spark arrestor cover on the exit side of the muffler. sound about right so far? (plus a carb tune..)


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## timberwolf

You gain HP in the form of RPM, torque may be about the same or slighly raised, but RPM shifts up 1000 RPM. This + more horse power  but also higher chain speed which = faster cutting. Because a good part of the gain is made in RPM some people claim 10% others 25% or more for the same saw, it depends on cutting style and your chain, if you take a muffler modded saw and lug it to the botem of the power band, it will have no more or little more than stock. Try to run a 5 foot bar with a dull chain and gains will be next to nothing. Run a sharp chain and short bar that will work well at high RPM and you will see bigger gains.


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## twoodward15

OK, I did the muffler mod on my homolite 33 cc saw today. I haven't cut any wood with it yet, but it definately runns faster and louder. It seems to actually run a bit smoother as well, but who knows. This weekend it'll cut some wood. Hopefully tomorrow I will get to do my McCulloch.


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## rmihalek

Remember to back out the high speed jet a quarter turn or so after opening up the muffler. The idea is to burn more fuel to make more power, so you have to let more fuel flow through the carb.


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## twoodward15

Exactly. I actually did a complete retune. I needed a very minor adjustment on my idle and low speed screw and a slightly bigger adjustment on the high speed screw. She runs good now and I can't wait to try it out.


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## timberwolf

Sounds about right, the extra LS and HS jetting is needed to make up not so much for the saw buring more fuel, but to make up for fuel being wasted.

The carb makes up for the extra fuel being burned. As air flow is increased, more fuel is drawn into the carb bore. The proof of that is how a saw will run on pipe or opened muffler with little or no change to jetting, more air is pumped by the engine, but more fuel is drawn by the increased air flow in the carb.

The price of power.:rockn:


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## Lakeside53

Wolf is totally correct! the converse is the EPA mufflers are heavily constrained such that you don't spew (as much) unburnt hydrocarbons in the environment.

The price of clean air or, get a 441.. or 575 or ...


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## aquan8tor

I searched around a bit, but couldnt find it, so here goes: 

Anybody know how much you can open up the exhaust on the muffler of an 029S farmboss?? Its actually my dad's saw; I just use it more than he does. 

Even with a fresh plug and a clean adjusted carb, the acceleration is suck-a$$. The little 024av that I opened up has faster acceleration!. The outlet of the 029S is roughly 1/2" square. 
I figure lots of people must have done this one, b/c its a relatively popular saw.


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## twoodward15

My Homelite PS33 muffler mod was easy and way way way out performs the stock saw. I can't believe how fast this saw cuts now as compared to stock. It amazes me how much better it runs and cuts. It is definately louder. I have a friend with a couple shindaiwas and it sounds like his 375. I see a saw race coming up in the near future!!!


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## CUCV

SWE#Kipp said:


> Four Paws do you think my outlet area is to big for a 372xpg ????



I have been interested in seeing Four Paws response to this question.

I have been thinking about DP one of my 372 for a while and this thread has motivated me to get going on it.
Does anyone have the stock 372 exhaust port area calculated (Or other saws for that matter)? 
I came up with 0.504in^2 for the 372. I measured the muffler hole to be 5/8" so the area is 0.307in^2. Thus using the 80%-85% rule the additional dual port muffler hole should be between .4" to .44" in Diameter (area between 0.125in^2 to 0.152in^2.)

So it seems to me like 2 additional 16mm ID holes are to much increasing the muffler exhaust hole area by 0.311in^2 each. That is unless the exhaust port has been ported. 

That leads me to another question. Does anyone have any advise or recommendations on porting and polishing a 372? I remember a while back reading a good thread on 372 porting but either I can't find it or it has been deleted.


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## CUCV

Opps made a typo

I calculated 372 exhaust port area at 0.54in^2 not 0.504in^2.


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## JUDGE1162

CUCV said:


> Opps made a typo
> 
> I calculated 372 exhaust port area at 0.54in^2 not 0.504in^2.




How did you go about calculating the exhaust port area????

I keep read like you that the muffler opening should be 80% of the exhaust port area, but not sure how to calculate it.


----------



## Four Paws

CUCV said:


> I have been interested in seeing Four Paws response to this question.
> 
> I have been thinking about DP one of my 372 for a while and this thread has motivated me to get going on it.
> Does anyone have the stock 372 exhaust port area calculated (Or other saws for that matter)?
> I came up with 0.504in^2 for the 372. I measured the muffler hole to be 5/8" so the area is 0.307in^2. Thus using the 80%-85% rule the additional dual port muffler hole should be between .4" to .44" in Diameter (area between 0.125in^2 to 0.152in^2.)
> 
> So it seems to me like 2 additional 16mm ID holes are to much increasing the muffler exhaust hole area by 0.311in^2 each. That is unless the exhaust port has been ported.
> 
> That leads me to another question. Does anyone have any advise or recommendations on porting and polishing a 372? I remember a while back reading a good thread on 372 porting but either I can't find it or it has been deleted.



The 80-85% I stated is a safety blanket statement. It is possible that you can take the muffler too far on any saw. You will get louder, but you will get no more power, and at times make your saws power flat on top. Two stroke engines need back-pressure to function - too much back pressure and they are stuffed up and not running optimal, too little back pressure and you are sending a LOT of your fresh charge (fuel+air = lots of waster power) out the exhaust.

On a 372 muffler, dual 1/2" ports would be fine.

As for porting and polishing a 372 - yeah, there are quite a few folks that have done it. It is likely THE MOST, or one of the most popular saws to mod. There are also some rough timing numbers floating around out there if you look hard enough. I wouldn't suggest porting a good saw yourself - at least not your first one. Port a Poulan Wildthingy that you pick up on eBay for $30 if you want to learn. 372 jugs aren't cheap! There is a LOT of good info out there, read and learn and be patient. A muffler mod is a good place to start. If you HAVE to have a woods port, give some of the saw builders a call. If you don't know who they are yet, you have more reading to do!

Josh


----------



## CUCV

JUDGE1162 said:


> How did you go about calculating the exhaust port area????
> 
> I took a piece of paper, put it inside the cylinder (cylinder off) then traced out the exhaust port. Then I took some measurements and started drawing in CAD. Once the CAD profile matched the trace I let CAD calculate the area.


----------



## timberwolf

CUCV, sounds like the area you measure may be off a bit, got to remember the port is a three dimentional opening in the saw, if you trace it an lay the paper flat and measure it the drawing will be wider than reality. Though making the mufler opening slightly more than .85 wont cause any major problems, you may even gain a little top end. I would not worry about it too much for calculating a muffler opening, but engine modifications it is worth considdering.


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## JUDGE1162

Is this something that is given by the manufactor some where like in a spec log or dealer/service manual?


----------



## CUCV

timberwolf said:


> CUCV, sounds like the area you measure may be off a bit, got to remember the port is a three dimentional opening in the saw, if you trace it an lay the paper flat and measure it the drawing will be wider than reality. Though making the mufler opening slightly more than .85 wont cause any major problems, you may even gain a little top end. I would not worry about it too much for calculating a muffler opening, but engine modifications it is worth considdering.



I have been thinking the same thing. When I get a bit more time I will try to draw it up in 3D. Basically I was wondering if others got similar numbers, or have others gone through and figured it out. I figured if I went with the 80% number that should cover the error.

Any specific engine mods you would suggest, specifics..?

FYI, I have an 044 that Dean modded for me and I have a 288 that is ported but needs other mods like timing and DP.


----------



## timberwolf

Dropped a word there, I had not intended to sugest an engine mod, but was trying to say it is worth taking the 3 dimentional port area into consideration if doing engine mod calculations.

372 has been modded well, puts it in with a stock dual port 066 at least in smaller wood.


----------



## brushswamper

*chainsaw mod*

i genneraly gut the mufflers of all garbage that the factory thinks is nessary
i did this w:rockn: :rockn: :rockn: :rockn: :rockn: :rockn: :rockn: ith a new 55cc craftsman and believe me it really did run


----------



## Gark

*029/MS290 revisited*

Like aquan8tor was asking about, an 029S muffler mod has been done here:
http://www.arboristsite.com/showthread.php?t=15986
which is found by a search of "MS290 Muffler". Thanks to rahtreelimbs. That muffler looks identical to one on my MS290, but I don't think mine will be quite as radical as that one.


----------



## aquan8tor

Gark said:


> Like aquan8tor was asking about, an 029S muffler mod has been done here:
> http://www.arboristsite.com/showthread.php?t=15986
> which is found by a search of "MS290 Muffler". Thanks to rahtreelimbs. That muffler looks identical to one on my MS290, but I don't think mine will be quite as radical as that one.




Thanks for the link. How much did you open yours up? Trying to stay functional---and I dont want to take any crap from Dad if he has problems with it. Thanks in advance.


----------



## rahtreelimbs

Be forewarned............when the 029/290 muffler is opened up like the one I did the saw is extremely loud!!!

This I can't explain...............with all the mufflers I have modded this is one of the loudest!!


----------



## aquan8tor

I opened the muffler of my 394XP a fair amount; it wasnt that noticeably different in volume. I suppose its more b/c it still (temporarily--until I have access to a mig welder) exits through the side. I'm going to put a 1" or 1.25" iron pipe elbow on it with a short pipe to divert the exhaust the he)) away from my face & hands while I'm milling with it. We'll see what it sounds like then.  Then I can play with the port size a little more.


----------



## artie__bc

Please help a newbie here! When you're talking about the 80-85% rule does this refer to the TOTAL area of the muffler ports, or just the ADDITIONAL area of the ports you're going to add?

artie


----------



## Lakeside53

Total


----------



## Urbicide

*Reply to artie bc*

It applies to the total area of the exhaust (existing and added openings).


----------



## Four Paws

artie__bc said:


> Please help a newbie here! When you're talking about the 80-85% rule does this refer to the TOTAL area of the muffler ports, or just the ADDITIONAL area of the ports you're going to add?
> 
> artie



If you would have read the entire thread, you will see that it was covered in post 6. Don't mind helping, but when the information is easily obtained in the thread you are posting in...SEARCH. It doesn't get much easier than that!

Welcome, and remember, 80-85% is a 'safe' guideline...some saws can be taken well beyond this without any ill results.


----------



## Urbicide

Hey Josh, he did say "Please."


----------



## Four Paws

Urbicide said:


> Hey Josh, he did say "Please."



Yup :yoyo:


----------



## artie__bc

Four Paws on one post you said the new hole should be 80 - 85% and on another you said combined SA of all holes. Just wanted some clarification before I start hacking at my muffler! Anyways, my 044's muffler already has a hole that equals about 80% of the cylinder port SA, so maybe I won't gain anything with a muffler mod? Has anyone here done an 044?


----------



## rbtree

I disagree that 80-85% is optimal, as measured against the port at the cylinder wall. Ken Dunn, venerable saw builder, used 125-150% as his baseline. 

most of my saws are probably at 100-125%, but have also been woods ported, which may allow for more opening. One, was muffler ported by Ed Heard way too much. It's a 346, and is very fast, but way too loud. Definitely no power fall off from too much port area. I do need to quiet it down though!!


----------



## Lakeside53

artie__bc said:


> Four Paws on one post you said the new hole should be 80 - 85% and on another you said combined SA of all holes. Just wanted some clarification before I start hacking at my muffler! Anyways, my 044's muffler already has a hole that equals about 80% of the cylinder port SA, so maybe I won't gain anything with a muffler mod? Has anyone here done an 044?




IMO... any number bandied around is just a WAG starting point, and will vary depending on whether you just do the muffler, make changes to the airbox/carb, or make other more radical changes.

On the very old 044 there is only a little to be gained. On the later 044, lots... If you're worried, make your hole adjustable with metal slide then do timed cuts. You'll quickly figure out "optimal", and trade off sound level... If you have a spare muffler front this is very simple... cut a long slot say 1/4 inch wide and have a screw-on on cover strip. Once you've figured out your optimal opening area you make make something more desirable - and either dual port the muffler or enlarge the existing hole.


----------



## Four Paws

artie__bc said:


> Four Paws on one post you said the new hole should be 80 - 85% and on another you said combined SA of all holes. Just wanted some clarification before I start hacking at my muffler! Anyways, my 044's muffler already has a hole that equals about 80% of the cylinder port SA, so maybe I won't gain anything with a muffler mod? Has anyone here done an 044?



Yes, I see that now. I should have said 'holes' and not hole. Even then, I could see how it might be confusing. I will edit the initial post for clarity. And, as Andy pointed out, these numbers are somewhat of a WAG. You can take a muffler too far - beyond the point that you gain any power and just make it louder (like rbtree said). rahtreelimbs opened up a Shindaiwa 488 muffler to the point that it wouldn't run well. The point here is more is not always better. Since the muffler mod is one of the first things (and maybe only thing) a new comer may do to their saw, the 80-85% was thrown in as a safe baseline. A woods ported saw will benefit from more surface area for the exhaust as the engine is now flowing more fuel and air. Also, as Andy mentioned, an older 044 will not benefit as much as a new 440 as the older saws have pretty free-flowing mufflers from the box.

Anyhow, good luck, and post up some pictures of your mod when you are done! 

Josh


----------



## Freakingstang

rbtree said:


> I disagree that 80-85% is optimal, as measured against the port at the cylinder wall. Ken Dunn, venerable saw builder, used 125-150% as his baseline.
> 
> most of my saws are probably at 100-125%, but have also been woods ported, which may allow for more opening. One, was muffler ported by Ed Heard way too much. It's a 346, and is very fast, but way too loud. Definitely no power fall off from too much port area. I do need to quiet it down though!!




I agree with you RBTree. I have never had power fall off from too much opening. Most of mine are 100-130% of the exhaust port at the cylinder (piston). 

A 372 works real good with a 1/2 x 1" oval hole. theory would say, based on the 80-85% that that is too much, but works extremely well.

While a saws needs some back pressure to run, it also needs to be able to breath.

My 346 has been opened up with two 3/8" holes in addition to the stock outlet. This wasn't done by me, but the builder who built the saw. It is entirely too loud, but hey, that is what muffs are for! 

The 80% rule is a guideline so you don't hack your muffler up. But don't be afraid to open it up a little at a time and check the results. You could be quite surprised.

An 044/046 breathes extremely well with the dual port muffler and both holes opened up. The last one i did, I believe was about 150% of the exhaust port and it could have taken more, but I was trying to be conservative.

Modded saws respond well to a bigger opening also.

Keep in mind, that you should put a spark screen in the new hole. This will also affect airflow up to 50% depending on the screen size. So sometimes the hole has to be bigger than one would think with a screen in place to get the best gains.


----------



## Lakeside53

Freakingstang said:


> ....
> 
> Keep in mind, that you should put a spark screen in the new hole. This will also affect airflow up to 50% depending on the screen size. So sometimes the hole has to be bigger than one would think with a screen in place to get the best gains.



The best way to do this is make your outlet the size you need, and arrange the screen so it's several times the area of the actual opening. This is what Stihl does on their pro saws and to some degree on all saws/*** - and if you do, you can pretty much just forget its effects both initially and over time. It's not just the new screen occlusion that matter - the wires get coated with fuel additive debris (that tan stuff - not just "soot") and get significantly thicker.

I showed one way of doing this on on the 361 muffler mod thread.


----------



## artie__bc

Yeah Andy, I saw the thread on your 361 mod, and I've got the parts to do it to my 044. I also have a big bore cylinder kit for it, and plan to install a Maxflow air filter, so maybe it'll benefit more from a little better exhaust flow. I guess if it doesn't work out it won't be too hard to weld the hole shut again. 
As far as whether it's an old or new 044, it's late 90's; does that make it old or new? It has the 12mm wrist pin.

Cheers, artie


----------



## Lakeside53

artie__bc said:


> Yeah Andy, I saw the thread on your 361 mod, and I've got the parts to do it to my 044. I also have a big bore cylinder kit for it, so maybe it'll benefit more from a little better flow than a stock cyl. I guess if it doesn't work out it won't be too hard to weld the hole shut again.
> As far as whether it's an old or new 044, it's late 90's; does that make it old or new? It has the 12mm wrist pin.
> 
> Cheers, artie




With the 12mm it's "newer", but the big muffler strangle didn't come until about until the 1999 production.


----------



## artie__bc

Yeah, this muffler is just a tin box with an inlet and outlet, no baffles or anything. Just a spark screen on the outlet. I've been considering, and I think the easiest thing would be to enlarge the outlet a bit. There's a lot of room to do that.


----------



## Lakeside53

artie__bc said:


> Yeah, this muffler is just a tin box with an inlet and outlet, no baffles or anything. Just a spark screen on the outlet. I've been considering, and I think the easiest thing would be to enlarge the outlet a bit. There's a lot of room to do that.




The easiest thing to do is slap a factory dual port front on it..


----------



## artie__bc

Do you have a part# Andy? My IPL hasn't come yet.


----------



## musch

Does anyone have photos of a MS260 muffler mod?
And yes, I did search the archives....opcorn:


----------



## Lakeside53

artie__bc said:


> Do you have a part# Andy? My IPL hasn't come yet.



1128 140 0801


----------



## Lakeside53

musch said:


> Does anyone have photos of a MS260 muffler mod?
> And yes, I did search the archives....opcorn:




Take off the front cover, remove the screen. You'll have one round hole about 3/8" in the center (back). Drill a 5/16 hole above it and one below it (don't go too deep). Debur the holes, re-insert the screen and it's done. Adjust your carb.


----------



## CUCV

Well I took some time and tried to draw my 372 exhaust port trace in 3D. Basically I wrapped the trace around a cylinder in CAD then took a cross-section of the extruded curves tangent to the cylinder. As expected it did decrease my estimated exhaust port area from 0.54 in^2 to 0.51 in^2.

So over the weekend I made my DP muffler for my 372 by adding a 0.4 in dia. hole.

I also modeled up my stock 288 and 357 exhaust ports in CAD.
I came up with .405 in^2 for the 357 and .607 in^2 for the 288.

Do these numbers agree with what anyone else has come up with?


----------



## timberwolf

Here are a couple of photos of an 026 muffler I did up today, a bit different, a bit more area, but cuts well.


----------



## CUCV

Does anyone know where to get a sheet of spark arrestor screen, or what saw has a larger than normal screen to be use on a DP mod?


----------



## Lakeside53

044 and 066 is pretty big. I have couple, of sheets but can't remember where I got them.


----------



## Freakingstang

Lakeside53 said:


> The best way to do this is make your outlet the size you need, and arrange the screen so it's several times the area of the actual opening. This is what Stihl does on their pro saws and to some degree on all saws/*** - and if you do, you can pretty much just forget its effects both initially and over time. It's not just the new screen occlusion that matter - the wires get coated with fuel additive debris (that tan stuff - not just "soot") and get significantly thicker.
> 
> I showed one way of doing this on on the 361 muffler mod thread.




I was referring to the screen pixel size, not the whole screen piece (ex 1"x2"). The diameter of the wires in the screen play a huge role in air flow.

I agree though, the screen should be bigger than the hole by a considerable amount.


----------



## scottr

*Wire cloth*

CUCV , www.mcmaster.com has wire cloth in sheets .


----------



## musch

timberwolf said:


> Here are a couple of photos of an 026 muffler I did up today, a bit different, a bit more area, but cuts well.



VERY NICE!!!
Does the location of the pipes heat up wood, or are you cutting mostly smaller stuff? 
I recently modded my 346xp similarly.
Pics will come soon.


----------



## artie__bc

Thanks Andy for the part # for the dual port muffler cover. I bought one and it works fine.:biggrinbounce2:


----------



## timberwolf

Musch, it only spends 1.5 seconds in a cut, just not enough time to heat the log up. 

I am working more towards racing than using it in the bush, there is no screen, though it would be easy to add one on the inside. Saw is boarder line as far as a woods saw anyway, compression is high and it is pretty much like trying to start an 066 without the decomp.


----------



## ASEMASTER

*you have made me sick*

it's 51 deg. outside the day before our whitetail deer rifle season and I need to put fire wood inside. BUT where am I? In my shop doing another muffler mod. on my cs340 now this thing has some bark with its bite . yeha am i going to cut some wood now.
I can't wait for the husky to get broke in so I can do it to it .:biggrinbounce2: :hmm3grin2orange:


----------



## gumneck

scottr said:


> CUCV , www.mcmaster.com has wire cloth in sheets .



Scott

You are a resourceful guy. I was just in Lowes looking for a rubber well nut for my Poulan 3300. Unfortunately your link didn't have 5/8ths diam by 1" long.


----------



## scottr

*3300*

Tom , what is a rubber well nut ?


----------



## gumneck

scottr said:


> Tom , what is a rubber well nut ?



Here ya go. Its the one on the right. The rubber piece on the left is part of the vib dampening holding one side of the handle to the flywheel side of saw. The first one lasted 10 years or more. But I've replaced two in the last two years. 

So I thought these things are just dry rotted on parts shelves by the time I got them. Decided to see if I can rig something up better. The wellnuts will work but I'll have to drill the caseing out a little to accomodate a bigger screw.

I've thought about using the two broken pieces with a longer screw and just putting the nut behind the rubber plug part(having drilled the plug part out for the screw to go thru).


----------



## scottr

*Barry mount*

Tom , that looks like a Barry mount . I wonder if you could make one with a threaded pipe and some silicone rubber .


----------



## CUCV

scottr said:


> CUCV , www.mcmaster.com has wire cloth in sheets .


Scott, Thanks for the tip! I was about to buy a strainer at Kitchen's etc.


----------



## Engineeringnerd

*My 372XP and 346XP muffler mods*

All this talk of muffler mods made me anxious, so I decided to break out the Dremel and BBQ paint on my 372XP and 346XP. I just mounted a 32" bar on the 372 and wanted to help it out with this mod before tackling a big oak in a few days. I also want to run a 20" bar a little faster with the 346. The 346 has worked reasonably well in the past with 20", but could do better.

I opted for the "thru-bracket" approach. The 372XP turned out the cleanest as far as fabrication goes. The hole is a rectangle with radius corners approximately 1" 1/16" wide x 9/16" High. I started by drilling two 1/2" holes next to each other, then ground out the rest with the Dremel. I went slightly larger since I was using a tight screen. Had to grind of the carb needle limiters to richen things up a bit. The 372 seems to run good, but I've only made a few cuts thus far. 

The 346XP mod was a little more difficult as I had to bend out a flange around the new muffler port to mate with the back side of the muffler bracket. The factory muffler has a gap between the muffler and the bracket, and I needed it to mate together in order to hold the screen in place. I cut a rectangle with radius corners 7/16" Wide x 9/16" High, once again using tight screening. Not as pretty a job as I would have like as it started to rain on the wet paint and caused it to blister. Runs really well though. The 346XP had plenty of carb adjustment, so didn't have to modify the needle limiters. It really seems to have livened up, but I haven't cut wood yet due to rain.

After all this Dremel work, I may become a dentist!


----------



## Freakingstang

engineeringnerd said:


> All this talk of muffler mods made me anxious, so I decided to break out the Dremel and BBQ paint on my 372XP and 346XP. I just mounted a 32" bar on the 372 and wanted to help it out with this mod before tackling a big oak in a few days. I also want to run a 20" bar a little faster with the 346. The 346 has worked reasonably well in the past with 20", but could do better.
> 
> I opted for the "thru-bracket" approach. The 372XP turned out the cleanest as far as fabrication goes. The hole is a rectangle with radius corners approximately 1" 1/16" wide x 9/16" High. I started by drilling two 1/2" holes next to each other, then ground out the rest with the Dremel. I went slightly larger since I was using a tight screen. Had to grind of the carb needle limiters to richen things up a bit. The 372 seems to run good, but I've only made a few cuts thus far.
> 
> The 346XP mod was a little more difficult as I had to bend out a flange around the new muffler port to mate with the back side of the muffler bracket. The factory muffler has a gap between the muffler and the bracket, and I needed it to mate together in order to hold the screen in place. I cut a rectangle with radius corners 7/16" Wide x 9/16" High, once again using tight screening. Not as pretty a job as I would have like as it started to rain on the wet paint and caused it to blister. Runs really well though. The 346XP had plenty of carb adjustment, so didn't have to modify the needle limiters. It really seams to have livened up, but I haven't cut wood yet due to rain.
> 
> After all this Dremel work, I may give up cutting wood and become a dentist!



Mods both look good, but you wouldn't need a 32" bar if you took those dawgs off. Too much dawg for east coast wood on that saw. Retarded huge, they are! 

You could probably get the same cutting surface with a 24" bar and the stock east coast spikes!!!!


----------



## Engineeringnerd

*Yeah*

I must agree the dawgs are a bit bigger than I expected when I ordered them. They are 1" longer than stock. Sure do grab the wood though!

Nothing about this saw makes sense for me anyway, pure weekend joy.


----------



## Rspike

engineeringnerd said:


> All this talk of muffler mods made me anxious, so I decided to break out the Dremel and BBQ paint on my 372XP and 346XP. I just mounted a 32" bar on the 372 and wanted to help it out with this mod before tackling a big oak in a few days. I also want to run a 20" bar a little faster with the 346. The 346 has worked reasonably well in the past with 20", but could do better.
> 
> I opted for the "thru-bracket" approach. The 372XP turned out the cleanest as far as fabrication goes. The hole is a rectangle with radius corners approximately 1" 1/16" wide x 9/16" High. I started by drilling two 1/2" holes next to each other, then ground out the rest with the Dremel. I went slightly larger since I was using a tight screen. Had to grind of the carb needle limiters to richen things up a bit. The 372 seems to run good, but I've only made a few cuts thus far.
> 
> The 346XP mod was a little more difficult as I had to bend out a flange around the new muffler port to mate with the back side of the muffler bracket. The factory muffler has a gap between the muffler and the bracket, and I needed it to mate together in order to hold the screen in place. I cut a rectangle with radius corners 7/16" Wide x 9/16" High, once again using tight screening. Not as pretty a job as I would have like as it started to rain on the wet paint and caused it to blister. Runs really well though. The 346XP had plenty of carb adjustment, so didn't have to modify the needle limiters. It really seems to have livened up, but I haven't cut wood yet due to rain.
> 
> After all this Dremel work, I may become a dentist!



Holy smaker ! Lets see a few side shot pic's of the 372XP with them monster 5 point dogs on her.


----------



## Engineeringnerd

*372XP with big feet (side pix)*

Here goes!


----------



## Rspike

Youz gots some *BIG* dogs there brother.
Just scare the tree down and then you dont have to cut it.

Are the dogs from Baileys ?


----------



## Engineeringnerd

*Let's start a new thread*

Rspike,

I'll start a new thread called "*Monster 372xp Dawgs*" so we don't hose up Four Paw's muffler mod string.


----------



## ASEMASTER

*jhonny 670*

gentlemen just did a shotgun mod. to the 670. i used 1/2" conduit cleaned off the gal. and brazed it and old exit shut with MA PP GAS never tired it before but read a post where they used it .not as fast as oxy.acet. but did a good job especially on such thin metal. have not tried in the wood as of yet but it sounds real nice.


----------



## CUCV

Finished up my first go around a couple muffler mods this weekend.

The first is a 372 project saw, I got the cylinder off a crushed saw on ebay. Total muffler port area is 85% of exhaust port. Used a 350 screen for the second port.

The second is 044/046 project saw. The muffler port area is 85% of the exhuast port with a screen inside. The crank bearings are locked, but I have a 046 ported cylinder to go on it when I get a new crank and bearings.

The third is a 288. The muffler port area is 87% of the exhuast port with a screen inside. Made a few cuts today but my tach batterys are dead so I didn't run it much. Wasn't as loud as I expected. Dean ported the cylinder and I plan to advance the timing when I get a chance.


----------



## tek9tim

How well does the chainbrake work on that 044?


----------



## CUCV

tek9tim said:


> How well does the chainbrake work on that 044?


1/8" of clearance when in the brake position and I am leaning on the handle.


----------



## dewclaw

Has anyone done the numbers on a muff mod for a stock 268XP ? 
What size I.D. pipe shoud I need , I think I will do the 2 hole mod. For that matter , what size I.D. pipe for a single hole mod in case I go that route? 

I want to be on the conservative side if anything , I dont want to over do it.

Thanks ahead of time for the replies.

Dew


----------



## timberwolf

Two pieces of 3/4 inch tube with about a 5/8 inside diamiter would be good, or one single with an inside about 13/16 would be good.


----------



## Canyon Angler

Lakeside,
Just to clarify in my mind -- to modify the muffler with the extra port and screen like you did in this thread, is there any need to actually heat and uncrimp the muffler? Or can you just drill and file a hole, braze on a piece of tubing, and clamp a piece of screen in there? Thanks,
Jeff


----------



## Lakeside53

Nope - read post #28!!!!! That is the "leave the crimp alone" method. And... the screen issue is also covered.


----------



## windthrown

*Welder muffler?*



sawn_penn said:


> Good timing! I'm modding my 034 muffler this weekend. My first challenge is that the previous owner welded the front cover onto the muffler - it makes getting at the internal screws a challenge!



Welded? Did you get the saw from a EPA employee or something? :hmm3grin2orange: 

I think that will be coming next. A tamper-proof EPA certified exhaust system for all future chainsaws! *sigh*


----------



## Canyon Angler

Thank you Lakeside!  I gotta try that!


----------



## Canyon Angler

One more question, Lakeside: What kind of brazing rod and flux did you use? I saw you mentioned flux but the brazing rods I recall seeing were just solid brass or bronze with no coating...also, do you know whether an acetylene torch like you would use for soldering copper pipe would be hot enough? Thanks again!


----------



## Lakeside53

I was using flux coated bronze rods - nothing special. The flux had probably melted of the rods if they are in the pictures. Just use any bronzing flux -heat the end of the rod, dip it in the flux powder and you are ready to go. 

Oxy-is acetylene (very low settting or you'll punch though the sheet steel) is what I use, but mapp gas is fine or in a squeeze, even propane works.


----------



## Canyon Angler

Thank you sir!


----------



## Lakeside53

post a pic when it's done!


----------



## parrisw

Can anyone advise me on how to retune after a muffler is modded, I ve setup carbs before, only on stock saws though. I usually hear people just say a little richer. Kinda hard to go by that. I want to do my Husky 394xp.


----------



## SWE#Kipp

Another 372 muffler mod ,,,,


----------



## Urbicide

SWE#Kipp said:


> Another 372 muffler mod ,,,,



Very nice job. Looks almost stock.


----------



## ispansco

Excellent work SWE#Kipp, the welds seem done by husqvarna
I put here also photos of my modification.
Greetings


----------



## SWE#Kipp

Nice work with muffler Ispansco 

And a question,,, what lens do you use on your camera ??
I got a Nikon D80 with their kit lens 18-55, not a super lens, but has to work until I can buy some new ones ,,,,,,,,


----------



## ispansco

*Nikon D70s with Tamron 28-75mm F/2.8 XR Di LD*



SWE#Kipp said:


> Nice work with muffler Ispansco
> 
> And a question,,, what lens do you use on your camera ??
> I got a Nikon D80 with their kit lens 18-55, not a super lens, but has to work until I can buy some new ones ,,,,,,,,



Hello SWE#Kipp,

It is difficult to explain it everything without knowing how to speak English,:bang: I will do the best thing than it can. Your lens is not indeed good . I have used for these photos a Tamron 28-75mm F/2.8 XR Di LD Aspherical (IF), I believe that it is of the best thing of the market in its focal rank that can one be bought without divorcing of the woman. Also they are the Nikon of high range like the 28-70 F/2.8 the 17-35 F/2.8 and 17-55 F/2.8 DX. They all best ones but are heavy and very expensive. If you need a wide-angle I recommend the Tokina 12-24 F/4 As good as the Tamron is of the best thing than it is possible to be bought to a reasonable price. As important as the lenses is to know how to take advantage of the possibilities the camera, to read many forums and to practice much.:camera: 

Greetings  

In order to value the lenses I recommend these Website to you: 

http://www.photozone.de/active/surv...' or brand='Tokina AF' or brand='Vivitar AF'"

And:

http://www.photozone.de/8Reviews/index.html


:greenchainsaw:


----------



## ispansco

SWE#Kipp said:


> Nice work with muffler Ispansco
> 
> And a question,,, what lens do you use on your camera ??
> I got a Nikon D80 with their kit lens 18-55, not a super lens, but has to work until I can buy some new ones ,,,,,,,,



Is understood well what I wrote?  :taped:


----------



## SWE#Kipp

Yes I understand you 
I'm gonna look at two lenses, one is Nikon 18-200 vr and the other lens is Tamron 17-50 2,8 for the kind of photos I take those two lenses seems to team up nicely


----------



## ispansco

The Tamron is very good lens, just as 28-75. The 18-70 is not very good but it is very practice by its ample focal rank.


----------



## Four Paws

You have Hijacked the thread...muffler mods, not cameras!


----------



## Trigger-Time

Another, Stihl 361 muffler mod, 

http://www.arboristsite.com/showthread.php?t=49342


----------



## gdn

If anyone interested in a 338 mod i posted this awhile ago. 

http://www.arboristsite.com/showthread.php?t=50562

but received no feedback  (not rep i want, feedback) 
I like the fact all the 338 mods i've seen are crude, dirty hillbilly engineering...
feel right at home 

here is one pic


----------



## West Texas

On the "H" jet I adjust it according to the 4 cycle sound rather than using a tach, as your rpms will change also with the muffler mod. I like to hear 'some' 4 cycle sound; but, not too much. When set properly, the 4 cycle sound will smooth out when you place the saw in wood at WOT. This is the setting that gives me the best performance.


----------



## parrisw

Thanks for the tip.

Will:chainsawguy:


----------



## justin028

*262xp muffler mod, and some ?'s*

wowww, i just did a muffler mod to my 262xp and now its really putting out some power. I ended up keeping the original side opening on the muffler opend, and ended up drilling out the front of the muffler where the cover plate goes on it. I put a 1/2 pipe in it and cut it back at an angle so it doesn't' interfere with bucking on big logs. After i did this i tuned the carb and its running perfect. Mainly i just had to adjust the h setting because there was a really noticeable increace in rpm. I took it out today to show my friend who's a logger, and he couldnt believe how well it responded to the mod. I let him run it and he said he couldn't tell the difference between my saw and his 266se. I just hope it dosent end up wearing anything out.does anything usually go wrong with a saw after doing a mod like this? Oh, and another ? i have is what is the correct fuel mixture for the 262xp. Ive been running 50:1 in it with 93 octane.:greenchainsaw:


----------



## timberwolf

The only thing that gets worn out is the mussles in your cheeks from grinning too much while cutting.

Real world the saw will run a bit cooler, but if it is producing more power and RPM there is no two ways about it that places a bit more load on internal engine parts. But on the other hand you run the saw less time to cut the same amount of wood so it would about equal out in the wash.

Just to be on the safe side I would add a little extra oil. 40:1 with good oil is cheep insurance. There is a lot of talk on mix ratio, but not too much can go wrong with a little extra, not so with any less than 50:1 mix.


----------



## woodchuck361

Lakeside53 said:


> then just remove all the internals and open the factory port - it is is in the best position for the hot gas flow when cutting. I'm not sure the results will be materially different to what I did with the additional front port.



would it be possible, (is there a reason it couldn't be done) , to gut the inside as you say and then add a spark arrestor screen / pouch to the enlarged factory hole? a suitable screen material would have to be located,then figure a way to fix it to the inside of the muffler case , but as you say the factory location is the best. Thanks for your thoughts on this.


----------



## Lakeside53

Anything's possible with enough time and money... but... not really. You'd have to open up the muffer and gut the old tube assembly that goes from the existing screen, then replace all of that.


----------



## joecool85

I love this thread  

I was wondering a couple things. First, why isn't this thread stickied? Second, what type of pipe are you guys using for the exhaust? Steel plumbing pipe? Also, is there any way to do a pipe mod without welding, like maybe with soldering?


----------



## Lakeside53

Lead/tin Solder will melt.. you can "braze" (technically "soldering)" with brass rod and map gas.


----------



## ScottWojo

joecool85 said:


> I love this thread
> 
> I was wondering a couple things. First, why isn't this thread stickied? Second, what type of pipe are you guys using for the exhaust? Steel plumbing pipe? Also, is there any way to do a pipe mod without welding, like maybe with soldering?



Joe,

I have made many modified mufflers. Without doubt the best material to use is stainless steel pipe. It will never rust and can either be painted or polished.

You can braize the pipe onto the muffler. Of course I prefer to weld using a mig welder.
POR 15 makes some High temp epoxy. But I have never tested this, nor would I ever want it on my saw.

If you have trouble locating sources of material to build your own muffler, send me a PM and I will help you.

With Great Esteem,
Scott.


----------



## Four Paws

ScottWojo said:


> Joe,
> 
> Without doubt the best material to use is stainless steel pipe. It will never rust and can either be painted or polished.



Scott, 

For most do-it-yourselfers, I would say stainless is not the best material to use as it is more expensive and harder to obtain than most other common materials. Worried about rust...stock mufflers are around 20ga. stamped sheetmetal...it will fall apart long before any kind of carbon tube/pipe will rust out. Also, you need to (should) weld carbon and stainless together with proper filler metal to prevent cracking...no big deal if you have a bunch of know-how and proper equipment...lots of shade-tree mechanics don't have access to such, and if they do, can't justify the expense of buying special wire/welding rod for a $2 muffler mod.

My advice to all the guys that want to mod their own mufflers is use anything you can scrounge. EMT (electrical conduit) works great and chances are you have some or can get your hands on some for free, or next to nothing. It is galvanized, so if you weld it, grind/sand off the galvanized, or weld in a well ventilated space - basically, just don't huff the fumes. Scraps of tube or pipe from pretty much anything - old hydraulic jack handle, etc. - will work wonderful. And, as Andy (Lakeside) said, you can braze with a $40 MAPP gas Bernz-o-matic torch and a flux covered brazing rod from the welding supply shop, TSC, Farm & Fleet, etc.

Don't forget the drill and chain file method works just fine if you will be cutting in an area which does not require spark arrestors. 

Good luck, and keep it cheap! 

Josh


----------



## Lakeside53

I'm too cheap to source thin wall pipe (for my 361 style mods) so I just turn down/bore black iron gas pipe! Coat of high temp paint and it will outlast the muffler material for sure. 


EMT is great (watch out for the zinc boiling off when wleding/brazing - don't breathe it).

yes, stainless is overkill, but if you have scrap...


Oh yes... watch out for the stainless mufflers appearing on Stihl pro saws next year... shut up Andy


----------



## ScottWojo

*Theres no such thing as a new diamond.*

Josh, I understand what you are saying, but you can buy stainless steel cheaper in a scrap yard than you can buy black pipe in the hardware store. You can buy stainless at $1.00 a pound. Sure you can buy the cheap steel there too at .10 cents a pound, but why not use stainless?

Theres no such thing as a new diamond.

By this I mean that two dollars will buy you enough material to build the highest quality stainless steel piped muffler. Stainless steel will never deteriorate, just like diamonds.

Yes, you can shop at Mc master to buy all new materials...(thats crazy!)
but even if you pay $2.00 a pound in a scrap yard you will have enough material to do all your saws.

And stainless steel is steel. Although I have not tried to braize it, I would see no reason you couldnt do it. If you know anyone with a welder, you know someone who can weld the pipe in. Its not magic. Use the smallest wire avail. and keep the hole tight and clean. Go slow on the thinner pipe. Use thicker walled pipe if you can get it. On the thicker walled stuff, weld on the pipe, and move the weld puddle into the muffler material with quick motions and stop. Let it cool and repeat. Its very easy to burn through the muffler and make big holes. Its also very easy to avoid doing that.

I live in an area with huge medical research facilitys, food preparation plants, and NASA. We even have a place that is building parts for secret satellite laser weaponry. There is never any shortage of stainless steel tubing.

Do not be afraid of using stainless, its just steel with a little nickle added. And if you really can not find the material to build a nice one, shoot me a pm.


----------



## gdn

i used copper pipe fittings, they transfer heat well for brazing and were pretty much the right shape to start off with. Also make some cool colours untill you run the saw.

i think they were $1.50AUD each...


----------



## joecool85

gdn said:


> i used copper pipe fittings, they transfer heat well for brazing and were pretty much the right shape to start off with. Also make some cool colours untill you run the saw.
> 
> i think they were $1.50AUD each...



Ah, I was interested in copper. Good to know it works. I've never tried brazing anything as I don't have a MAP setup. I should really get one sometime. Luckily my current project has a 2 piece muffler that I can take apart to mod so I don't _have_ to weld/braze anything. I definetely want to on my next one though, I love some of the pipe mods.


----------



## ScottWojo

joecool85 said:


> Ah, I was interested in copper. Good to know it works. I've never tried brazing anything as I don't have a MAP setup. I should really get one sometime. Luckily my current project has a 2 piece muffler that I can take apart to mod so I don't _have_ to weld/braze anything. I definetely want to on my next one though, I love some of the pipe mods.




Joe,

If you consider copper, keep in mind where you place it as it is very soft. Especially when it becomes warm.

What model saw are you considering modding? If you tell me what size ID pipe you need, I could send you out an already made insert that all you would have to do is cut the hole, stick it in and take it over to your nearest auto muffler shop and have em weld it in.

And I would send you the insert no charge, Thats one with the screen already built in. And no charge means free shipping too!


----------



## joecool85

ScottWojo said:


> Joe,
> 
> If you consider copper, keep in mind where you place it as it is very soft. Especially when it becomes warm.
> 
> What model saw are you considering modding? If you tell me what size ID pipe you need, I could send you out an already made insert that all you would have to do is cut the hole, stick it in and take it over to your nearest auto muffler shop and have em weld it in.
> 
> And I would send you the insert no charge, Thats one with the screen already built in. And no charge means free shipping too!



I'm actually not sure yet, it will depend on what I can find for another project saw  I appreciate the offer, and I may take you up on it later on.


----------



## timistall

Or do it this way.


----------



## ScottWojo

timistall said:


> Or do it this way.



Tim!

Thats a great mod, Have some Wojo Mojo. Did you do it yourself?

I think he does not have a welder. He could do that using some Stainless screen, the metal diverter, high temp silicone to seal the small gaps. And a couple of stainless steel Rivets.

You can get the Rivets from a restoration supply company. Thats also where I buy my High Temp POR 15 paint.

Scott.


----------



## troutfisher

ScottWojo said:


> . He could do that using some Stainless screen, the metal diverter, high temp silicone to seal the small gaps. And a couple of stainless steel Rivets.
> 
> Scott.




You can use high temp silicone in a muffler? I didn't know it would take that much heat.


----------



## ScottWojo

troutfisher said:


> You can use high temp silicone in a muffler? I didn't know it would take that much heat.




I have to think that you are on the outside of the muffler, and you are effectively lowering the exhaust temp by opening the muffler.

I feel that you shouldn't use it at the cylinder port, but on the outside of an opened up muffler you would be ok with the red stuff.

With a wider diverter and some really tight rivets, it probably wouldn't make much differance if you did not use the silicone.

And again, POR 15 makes some High Temp epoxy that would work in conjunction with really high quality rivets. (of course you should us closed rivets so you do not affect the area of the added open port)


----------



## gdn

joecool85 said:


> I'm actually not sure yet, it will depend on what I can find for another project saw  I appreciate the offer, and I may take you up on it later on.



brazing is hell easy, I bought a benzomatic torch for 80AUD, few plumbing rods and some flux and was good to go. First braze ever was on the saw muffler, and it came up hell strong. I think it's a good idea to wire brush the metal before you start as since then i brazed onto a cat muffler and it took all of 2hrs to fall off.


----------



## Lakeside53

ScottWojo said:


> Tim!
> 
> Thats a great mod, Have some Wojo Mojo. Did you do it yourself?
> 
> I think he does not have a welder. He could do that using some Stainless screen, the metal diverter, high temp silicone to seal the small gaps. And a couple of stainless steel Rivets.
> 
> You can get the Rivets from a restoration supply company. Thats also where I buy my High Temp POR 15 paint.
> 
> Scott.



The exhaust gasses are 1200 to 1400F at the engine, and tad lower at the exhaust.... Good luck with any silicone, even chimney grade...


----------



## timistall

Mine is welded.


----------



## ScottWojo

Lakeside53 said:


> The exhaust gasses are 1200 to 1400F at the engine, and tad lower at the exhaust.... Good luck with any silicone, even chimney grade...



Andy, there is a major chemical manufacturer that has a silicone avail that has a 100 hour continuous service life at 602 degrees farenheit. The Epoxy has an operating temp of 1500F.
We are not talking about the interior of the muffler near the exhaust stream close to the cylinder port. You would have to agree that the temperature on the outside of the muffler that is exposed to the 10 degrees to 100 degrees farenheit atmosphere would be more than a "tad" lower than the usual 600C on the inside of the exhaust stream. The would be greatly lowered in a modified muffler that breathes easier with less restriction.


----------



## rahtreelimbs

Just put a hole in it!!!


----------



## Trigger-Time

Lakeside53 said:


> Oh yes... watch out for the stainless mufflers appearing on Stihl pro saws next year... shut up Andy



I hope that don't mean...................*CAT!*


----------



## Urbicide

Trigger-Time said:


> I hope that don't mean...................*CAT!*



Meow !


----------



## Lakeside53

ScottWojo said:


> Andy, there is a major chemical manufacturer that has a silicone avail that has a 100 hour continuous service life at 602 degrees farenheit. The Epoxy has an operating temp of 1500F.
> We are not talking about the interior of the muffler near the exhaust stream close to the cylinder port. You would have to agree that the temperature on the outside of the muffler that is exposed to the 10 degrees to 100 degrees farenheit atmosphere would be more than a "tad" lower than the usual 600C on the inside of the exhaust stream. The would be greatly lowered in a modified muffler that breathes easier with less restriction.



Sorry.. wrong stuff for the application. 602F is no where near enough... Epoxy operating at at 1500? show me... 

BTW.. I have measured exhaust at over 1000F on a 361 - my mod. ... at full power, not wot...


----------



## Lakeside53

Trigger-Time said:


> I hope that don't mean...................*CAT!*



nope.. and I've said enoigh (for today).


----------



## Al Smith

I'm a thinkin old Scott is talking about sodium silicate not to be confused with silicon caulking compound.You can half-fast fix a broken exhaust manifold with sodium silicate,works for a while .With silicon it might work,oh maybe 10 seconds or less.


----------



## Sawin

*And speaking of Mapp Gas...*

What is the best adjustment of the flame to get the most heat? It seems that more heat is produced by using more gas...


----------



## Al Smith

More heat,get a bigger tip.I don't like the stuff myself.It's a lot cheaper than acetlylene but doesn't put out near the heat or cut nearly as good as good old.'cetlene.Old school.ya know.


----------



## Lakeside53

Al Smith said:


> I'm a thinkin old Scott is talking about sodium silicate not to be confused with silicon caulking compound.You can half-fast fix a broken exhaust manifold with sodium silicate,works for a while .With silicon it might work,oh maybe 10 seconds or less.



yep... but I still want to see the 1500F epoxy..


----------



## Urbicide

Lakeside53 said:


> nope.. and I've said enoigh (for today).



Andy, your such a tease. opcorn:


----------



## Al Smith

Lakeside53 said:


> yep... but I still want to see the 1500F epoxy..


Oh they have some supposidly that will hold up to 2000 degrees but they wouldn't hold up to the vibration of an exhaust system[McMaster -Carr].If it were me,I would work on my welding a little bit rather than use "bondo" to make it look pretty.

But alas,who am I to say.I just slice out a hole with a die grinder and omit the little pipe thingy and most likely get the same results.I have made little louvers if that counts for anything.:biggrinbounce2:


----------



## ScottWojo

Here ya go ol' pal's. I knocked out the manufacturer so ya couldn't report me for non sponsor selling again.

And Al, if you remeber reading my post, you would recall that I only suggested adding it as a sealer between the metal that was riveted. I never suggested that you merely stick the diverter on with epoxy.

Yes welding is the best for adding exhaust diverters. But there is interest for people who have no welding or braizing talent.

Also the product that initially suggested was a manifold repair product from the same place that supplies my muffler paint. And yes it is 1500 degree epoxy.

But I will do one better, since Andys mods are developing temperatures that are so extreme, perhaps he would need higher temp epoxy such as below.




> 2000°F High Temperature Stainless Putty
> Durabond 7032 Stainless Putty will repair and seal high temperature equipment with the ease of ******* high performance systems.
> 
> This smooth creamy paste has no harsh odors, will not run, drip or sag and cures at room temperature to form a machinable composite.
> 
> Offers excellent adhesion, resistance to heat, chemicals and solvents.
> 
> Ideal For repairing and rebuilding worn or cracked composites, dies, fixtures, jigs; fills holes and leaks in automotive, maintenance and industrial applications.



I know some how this is not true, and you will find some reason to argue further. Ok let me have it....


----------



## Al Smith

Yep,that's the stuff alright.I really don't care how you stick them together.You could make them out of pure nickle and heli-arc them for all I care.They won't run any better though.

I doubt Andy is BS ing about the temperature.Do you have a pyrometer Scott to be able to tell your temperatures on the exhaust? I don't myself.


----------



## Lakeside53

I know about that stuff..it may be semantics, but it's certainly not an epoxy... note that it's one part to begin with. I was using similar stuff 30 years ago to fix the holes in my car mufflers.. when I was way too poor (or nuts) to replace them. In my opinion... way too brittle to be of much use on a saw, and I'd be worried about pieces getting inside and rattling around. The stuff sets up like stone (it is a ceramic).

And yes, I was playing with an EGT gauge that reads up to 1800F to see if I could tune the saw just like setting the mixture on an airplane engine (reciprocating). The answer was .. maybe... but not worth the messing around unless you had a dyno load to make it practical. Holding a saw at a constant full power in wood while reading the temps and fiddling with the saw is real pain! It was supposely accurate to +/- 50F, and I might well have been too lean at the peak reading, but... 


I use paint that's rated to 1200F, but.. it also burns off in the hot spots.


----------



## MikE2

So exactally how do you adjust the carburator after opening the muffler up? I realize you need more fuel for the extra air flow, I just don't know how much or how to adjust it. Its a 357XP


----------



## Outlaw5.0

What about welding a tube onto the cover, then threading the tube and using one those screw in outlet/spark arrestors that are used on weed whips and blowers?.


----------



## MikE2

on my 357, According to my calculations a 3/4" hole should make 85% of the size of the port on the cylinder, including the original exhaust outlet. So should I also enlargen the hole on the baffle on the inside of the muffler too, or just leave that alone and drill out the hole on the front of it?


----------



## ScottWojo

MikE2 said:


> on my 357, According to my calculations a 3/4" hole should make 85% of the size of the port on the cylinder, including the original exhaust outlet. So should I also enlargen the hole on the baffle on the inside of the muffler too, or just leave that alone and drill out the hole on the front of it?



When I have to crack the nut, I will blow out as much of the baffle as possible. You heat the crimps up cherry red in the daylight and pry em open. Just keep doing it untill the muffler falls apart. Then you can just slide it back together and recrimp the uncrimped parts once all the work is done. Just heatem back up and recrimp. Its very easy to make the muffler appear that it had never been opend up.

Keep in mind the area that is flow restricted by added screens in the port.


Hope This helps,
Scott.


----------



## MikE2

ScottWojo said:


> Keep in mind the area that is flow restricted by added screens in the port.



Thats the next thing I was going to ask. Thanks for the information. I realy appreciate it.

So any idea on how to richen the mixture up?


----------



## kevinj

ScottWojo said:


> When I have to crack the nut, I will blow out as much of the baffle as possible. You heat the crimps up cherry red in the daylight and pry em open. Just keep doing it untill the muffler falls apart. Then you can just slide it back together and recrimp the uncrimped parts once all the work is done. Just heatem back up and recrimp. Its very easy to make the muffler appear that it had never been opend up.
> 
> Keep in mind the area that is flow restricted by added screens in the port.
> 
> 
> Hope This helps,
> Scott.




Wont that start yer saw on fire though ???
Or, should we take off the muffler ???

 












just kidding...
I always keep a bucket of water nearby...


----------



## Four Paws

MikE2 said:


> Thats the next thing I was going to ask. Thanks for the information. I realy appreciate it.
> 
> So any idea on how to richen the mixture up?



DOOD, use the search function! This information has been covered a million times. If you read the entire thread...from the beginning...you will find most of your questions have already been answered.


----------



## OLY-JIM

Lake, it's been some time since you've performed this Muff-Mod; have you had any issues with the clip that's pinched around your spark arrestor screen coming off or losing tension?


----------



## Lakeside53

Nope. If anything they get real tight!


----------



## monkeyboi

The clamp he used is designed to be self-adjusting-much preferred over screw-type clamps.


----------



## cmetalbend

sawn_penn said:


> Good timing! I'm modding my 034 muffler this weekend. My first challenge is that the previous owner welded the front cover onto the muffler - it makes getting at the internal screws a challenge!



My wife says "cute" and SAW should never be used in the same sentence.


----------



## joe_30psi

*time to do my 361*

From all the reading and watching others, i believe I am gonna do mine.i love the way the saw cuts now. Can't wait to see it after the mod. All i need is the pipe and i'm gonna check on some on monday. Did anyone else notice a huge difference in their 361 after about 10 tanks of fuel or so.Mine is nite and day in power. Be the way awsome work lakeside joe


----------



## country boy

*2159 mod*

here is a pic of my 2159 i just got done i copied the double barrel muffler that a guy done that i seen in this thread.The muffler i started with was a non cat that i have been running for a while on it just had a hard time getting up the nerve to butcher it. After it was welded up and done i took it to the saw shop for retuning . fired it up and it was running lean it was turning just a hair over 14,000 tuned it back down around 13,500. It sounds really good cant wait to get er burried into some oak. I'll let you all now how she cuts when i get back to the timber and get a better closeup pic. This has been a great thread with tons of info thanks guys!!! <a href="http://s220.photobucket.com/albums/dd71/timberguy/?action=view&current=chainsawmufflermod011.jpg" target="_blank"><img src="http://i220.photobucket.com/albums/dd71/timberguy/chainsawmufflermod011.jpg" border="0" alt="Photobucket"></a>ad


----------



## novaman64

For those of you that have done the mods on the 359's, what size holes are you finding works the best?


----------



## stihl 440

*Dp*

Just modded my 280's muffler tonight. I used two 1/2" copper pipe, brazed them in, and took the baffle out, and cut the deflector off and blocked off the stock outlet. I put her all back together and started her up and adjusted the idle first, the tached it it was at 14,100. I turned it back down to 13,500 which is where it was before the mod. It is a walker style mod. It cuts and sounds awesome!:greenchainsaw:


----------



## country boy

novaman64 said:


> For those of you that have done the mods on the 359's, what size holes are you finding works the best?



I am not real sure what works the best but on mine i went with dual 1/2" id pipe and crimped off the pipe going to the factory top exaust outlet afraid of exceeding the 85% rule. <a href="http://s220.photobucket.com/albums/dd71/timberguy/?action=view&current=2chainsaw004.jpg" target="_blank"><img src="http://i220.photobucket.com/albums/dd71/timberguy/2chainsaw004.jpg" border="0" alt="Photobucket"></a>


----------



## user 19670

ScottWojo said:


> Josh, I understand what you are saying, but you can buy stainless steel cheaper in a scrap yard than you can buy black pipe in the hardware store. You can buy stainless at $1.00 a pound. Sure you can buy the cheap steel there too at .10 cents a pound, but why not use stainless?
> 
> Theres no such thing as a new diamond.
> 
> By this I mean that two dollars will buy you enough material to build the highest quality stainless steel piped muffler. Stainless steel will never deteriorate, just like diamonds.
> 
> Yes, you can shop at Mc master to buy all new materials...(thats crazy!)
> but even if you pay $2.00 a pound in a scrap yard you will have enough material to do all your saws.
> 
> And stainless steel is steel. Although I have not tried to braize it, I would see no reason you couldnt do it. If you know anyone with a welder, you know someone who can weld the pipe in. Its not magic. Use the smallest wire avail. and keep the hole tight and clean. Go slow on the thinner pipe. Use thicker walled pipe if you can get it. On the thicker walled stuff, weld on the pipe, and move the weld puddle into the muffler material with quick motions and stop. Let it cool and repeat. Its very easy to burn through the muffler and make big holes. Its also very easy to avoid doing that.
> 
> I live in an area with huge medical research facilitys, food preparation plants, and NASA. We even have a place that is building parts for secret satellite laser weaponry. There is never any shortage of stainless steel tubing.
> 
> Do not be afraid of using stainless, its just steel with a little nickle added. And if you really can not find the material to build a nice one, shoot me a pm.




Originally stainless was steel and some nickle but actually, there are now more stainless alloys than you can imagine.

Stainless doesn't always mean non-rusting (try Wally World stainless cutlery and see what I mean).

Stainless steel is really a misnomer in some cases. Many alloys exist that have no steel at all in them.

Some stainless doesn't braze well (or easily for that matter) and it takes better than a bottom of the line MIG from the local hardware store to manage welding stainless properly (and a different gas than you use with ferrus metals). Special alloy electrodes (wire) are required to join ferrus metal to stainless with any degree of reliability under any conditions and then we add heat/cool cycles.


----------



## Tzed250

Gordie, all steel is ferrous. <[sp] Stainless implies a minimum nickel content.


----------



## sawfix

Tzed250 said:


> Gordie, all steel is ferrous. <[sp] Stainless implies a minimum nickel content.



i think ya got that backwords stainless has a high chromium or nickle content like inconel.


----------



## slabhead

I pulled the screen on my 365 Special, totally gutted the insides.Is there any thing else to be gained over expanding the factory outlet? easily done w/ big blade screwdriver.Noise is not a problem-can't hear anyting w / muffs on,


----------



## Bowtie

joe_30psi said:


> From all the reading and watching others, i believe I am gonna do mine.i love the way the saw cuts now. Can't wait to see it after the mod. All i need is the pipe and i'm gonna check on some on monday. Did anyone else notice a huge difference in their 361 after about 10 tanks of fuel or so.Mine is nite and day in power. Be the way awsome work lakeside joe



Do the muffler mod like Lakeside53 did and you will be very impressed. I did that and switched from a 7 tooth rim sprocket to an 8 tooth rim, and Its an awesome machine! (With sharp Stihl RSC chain)


----------



## Greg Lees

I have everything to mod my 361's muffler, but I'm having trouble finding the right diameter pipe (.625-.630 OD). All "1/2 inch" conduit is really 5/8" ID and is too large for the 16mm screen to fit over. Has anyone found a supplier that has the proper size?


----------



## Bowtie

Greg Lees said:


> I have everything to mod my 361's muffler, but I'm having trouble finding the right diameter pipe (.625-.630 OD). All "1/2 inch" conduit is really 5/8" ID and is too large for the 16mm screen to fit over. Has anyone found a supplier that has the proper size?



True Value Hardwae


----------



## djauto

Greg Lees said:


> I have everything to mod my 361's muffler, but I'm having trouble finding the right diameter pipe (.625-.630 OD). All "1/2 inch" conduit is really 5/8" ID and is too large for the 16mm screen to fit over. Has anyone found a supplier that has the proper size?




Greg,

I used a 1/2" BOLT SPACER, like bowtie said, any hardware store should have it. The 16mm screen fits perfect in it. It is rolled steel so it has a seem along it that you can easily weld or braze up. The ID could be a little larger with thinner wall thickness for better flow (they come with .060 or so wall thickness and 5/8 or .625" OD with .505" ID) but it works excellent and cost $.18.

Brian


----------



## Bowtie

djauto said:


> Greg,
> 
> I used a 1/2" BOLT SPACER, like bowtie said, any hardware store should have it. The 16mm screen fits perfect in it. It is rolled steel so it has a seem along it that you can easily weld or braze up. The ID could be a little larger with thinner wall thickness for better flow (they come with .060 or so wall thickness and 5/8 or .625" OD with .505" ID) but it works excellent and cost $.18.
> 
> Brian



Good point on the ID of the bolt spacer pipe. I dremel all my modded 361 mufflers until they make me smile.


----------



## Wet1

parrisw said:


> Can anyone advise me on how to retune after a muffler is modded, I ve setup carbs before, only on stock saws though. I usually hear people just say a little richer. Kinda hard to go by that. I want to do my Husky 394xp.



Any other tips for tuning after this mod???




I'm considering doing this on my 036, is there much of an improvement on this model?


----------



## woodchuck361

I'm going to try something new. First off anyone found a source for spark arrestor screen? I have opened my 361 muffler and cut the small outlet port completely out all the way down to the spark arrestor. Enlarged the exit hole and will make a spark arrestor "sock to fit over the metal pipe with all the holes in it. Not sure of the proper name of it.
http://www.arboristsite.com/attachment.php?attachmentid=74184&d=1215652585
muff 1.jpg
http://www.arboristsite.com/attachment.php?attachmentid=74185&d=1215652618
muff2.jpg


----------



## Lakeside53

How will you ever clean it?


----------



## woodchuck361

Well...... how often do they need cleaning? Its either that or no spark arrestor at all. I don't cut on government land or anywhere that requires one. just though it would be a good idea, and if the arrestor were really large it would not need cleaning that often.


----------



## Lakeside53

Maybe so.. but that why all spark screens are accessible...

I clean (burn off with propane) about 5 a week... mainly due to dumb operators, but...


----------



## woodchuck361

after the muffler mod the high side should be turned out about 1/8-1/4 turn? mine was all the way on the on the limiter stop. I pulled both limiter caps, trimmed the stops off and reinstalled in the same location the screw will now turn more but how much? I have gone about 1/4 turn to the left should I be going to the right? Do the screws on all saws adjust richer to the left and lean to the right or do I have it backwards? I have only started it saw up and blipped the throttle twice not sure on the adjustments. Its to expensive to screw up. thanks


----------



## Lakeside53

You have it correct.... start it and tune it...


----------



## woodchuck361

YOU TRULY ARE THE MAN THANKS AGAIN. Oh I am going to source another muffler and make a pipe that goes from the enlarged exhaust port to the stock spark arrestor location and make a press fit connection like the stock muffler. I will cut out the spot welds that hold the arrestor assembly in place, trim the small pipe and braise a larger pipe in place. Then fit and braise a connector sleeve in the exhaust opening. Then tac the assembly back in place. The same system as stock Just with a larger pipe . Your words about the arrestor needing to be serviceable are TRUTH. After thinking about it long and hard I can't think of another or better way to do it while keeping the stock look, and I do think the arrestor is important. I will try to post up pics as the process progresses. Now to find a muffler Thanks again Lake.


----------



## Greg Lees

Well, after looking in every hardware and plumbing store in Nashville/Franklin for the right kind of tubing for the muffler port, I went to a machine shop. The owner didn't have anything on hand, but he did have a catalog from McMaster-Carr...

Here's the website address:

http://www.mcmaster.com/

...and here's the part number for .625 OD, .350 ID steel tubing:

89955K27

The tube is a perfect fit both inside and out. The screen fits, the clip fits. Only downside is you have to buy 6' length. It's $23 for the tube, plus shipping. You'll have enough tubing to mod saw mufflers for a while....

Greg


----------



## Lakeside53

0.350 Id?


----------



## Greg Lees

Oops...typed too quickly.

.035" wall thickness, not ID.


----------



## Lakeside53

lolol.. 035 wall thickness!


----------



## Lakeside53

It's a trade off - idle stability, fuel consumption, noise... rule of thumb - 85% of the cylinder exhaust. 

I like the 16mm I use... (in addition to the factory port). Anything more is dimishishing returns, espocially if you don't look at the inlet end.

Search for a thread by TIMBERWOLF - he did a sereis of experiments on an 026.


----------



## davefr

*Thanks Andy!!*

I've procrastinated doing this mod but your procedure worked great. Our local Ace Hardware has 5/8 X 1/2 X 1.5" solid steel spacers. They're in the slide out cases of specialized hardware. I've ordered the screen and clamp so that comes later. The muffler just came out of the oven from being coated with exhaust paint:


----------



## Lakeside53

Looks great! but you might have a problem getting the screen on 1/16 inch wall pipe...


----------



## davefr

Andy,
Is the screen really that tough to shape? I could always expand the I.D. of the pipe or taper it in with a reamer to fine tune the fit.

Thanks


----------



## Lakeside53

Yes.. it's a PITA! 

Yes... Ream out the inside of the pipe. Tapered reamer will work as you only need 3/16 thinner for the mesh end.


----------



## JUST4FUN

Andy, do you do these muffler mods for other people? How much would it be for me to send my saw to you and get this done? Thanks


----------



## Lakeside53

I usually forward such requests to other AS members that do a fine job...


----------



## JUST4FUN

Thanks for the quick reply. Who are the saw builders here? It's been awhile since I've read this forum much. A friend of mine has a good size red oak down. It's not in the way so will probably wait for cooler weather to cut it but it is looks to be more than 40" in diameter and I want to get a 25" bar for my ms361 and need all the power I can get!!!


----------



## Four Paws

I don't know if people are still modding their mufflers these days...but I thought I would share a muffler I worked over this afternoon. This is from a 621 Redmax. The stocker was OK I guess. I like the exit on the front...just too small, and covered up with a spark screen.

In the vise ready to get split.






I used my oxy acetylene torch with a 00 tip to heat the seam. Used a flat screwdriver to pry the lip up so I could split the two halves apart.






Here it is apart. The baffle is still installed...but not for long.






The baffle is now removed. Noticed how much I opened up the outlet.






Finally back together. Crimp the seam tight with some large channel locks. Make sure the screw guides inside the muffler are lined up properly before you crimp, or else you will be taking it all back apart. Massaged the deflector a bit, wire brushed it, and finished it off with a fresh coat of paint.






Pretty straightforward, I know. But it might help somebody try modding their own muffler...and that is what counts!

Josh


----------



## blsnelling

Good work the Italian Stallion.


----------



## Ghillie

Thanks for bumping your thread back up four paws, nice work on the mod!


----------



## lectrocrew

I hope I can post this before I loose power again. The eye of Tropical storm Fay has been on top of where I live for the last 20 hours or so but we got several trees blown down last night (I cut 2 of my house and 1 small white oak off the power line with my small saw) as the west side of the storm came through and as I type this the east side is kicking up some strong winds, so I expect more downed trees tonight. 

My MS660 muffler mod:
I've been waiting for my cover-to-muffler gasket to come in at my Stihl dealer but 2 nieghbors called with big blown down trees for me to cut so I bolted my modded muffler back on this morning.

Here's what I tried first, cutting the front of the baffle cage out and enlarging the output hole.











Then I cut the cage out completely with a plasma cutter and die grinder and fabricated a support plate out of .0625" stainless steel. The original muffler inlet opening was .140" narrower than the cylinder exhaust port so I milled .070" off each side of the muffler inlet opening. I matched the opening of my stainless support plate to the cylinder exhaust port and the 'now wider' muffler inlet. 
Next I milled .005" across the muffler-to-cylinder gasket surface of the muffler in order to guarantee a flat gasket seal surface. 
Then I TIG spot welded the stainless bracket to the muffler housing.
NOTE: _I don't have pictures of the progress of the machining work since I did it in the shop where I work as an industrial maintnance mechanic. Our factory does not allow cameras inside due to trade secrets of our proccesses._ Sorry  
But here are pics of the finished work:











I'll post a couple more pics in the next post:


----------



## lectrocrew

My dual port cover (pn 1122 140 0800) came in at my Stihl dealer but not my gasket so I had to use high temp RTV sealer for now to get my saw running to cut all these trees the storm has blown down. I'll go back and put the gasket in there when I get it.











I tuned the carb to the new exhaust and cut some wood. WOW, this saw gives me a virtual adrenaline overdose.


----------



## hawkfeather

*Pipe size*



Lakeside53 said:


> If you are going to use the Stihl spark arresters, you do need to get the pipe size figured first. The mesh is surprisingly tough and difficult to "mash" into anything other than what it was designed for. I turned (on a lathe) a 1/2 inch sleeve (about 12.8mm ID) until it was 14.3mm on the outside... Easier than driving 25 miles to get the right tube, but... I'm just going to get the right 5/8 (15.8mm) or .630 OD tube (16mm) and use the 16mm arrester/clip. 6 feet of it will keep me in muffler mod supplies for a lifetime.
> 
> The good thing about figuring this out is that it applies to any mid-size saw, not just Stihl. I thought about 2 14mm tubes on the right hand side of the 361 muffler (there is room), but I just don't need the outlet area. One 16mm will be plenty. Maybe on 80cc class or above I can add multiples.
> 
> Now to figure out what to do with my 088! (actually, that one is a no brainer...) and it's already so damn loud no one will notice if it gets louder



Anyone know if this tube size will work without re-sizing it???

0.625" OD x 0.058" WALL x 0.509" ID A513 TYPE 5 TUBE


----------



## Lakeside53

That should work. Pretty thin for brazing though... I now leave a thicker base to make brazing easier - just thin out the top 1/4 inch for the screen/clip


----------



## hawkfeather

Cool, thanks lake. Hey do you have to get new covers for the two screw holes?


----------



## hawkfeather

Oh, and are the 16mm screen and clamp usually stocked items or special order?


----------



## Lakeside53

hawkfeather said:


> Cool, thanks lake. Hey do you have to get new covers for the two screw holes?



nope... I also added to the orginal reply to your post..


----------



## Lakeside53

hawkfeather said:


> Oh, and are the 16mm screen and clamp usually stocked items or special order?



Your dealer probably won't have them in stock as nobody ever replaces the TS400 screens! We get ours overnight though... like almost every stihl part.


----------



## davefr

My 5/8" X 1/2" solid steel spacer worked great. The screen fit like a glove. In my experience there was no need for anything thinner then about .0625 wall. However maybe it's YMMV depending on actual screen tolerances.


----------



## hawkfeather

I can get a foot of that tubing for $1.70 from Online Metals here:

http://www.onlinemetals.com/merchant.cfm?pid=15520&step=4&showunits=inches&id=283&top_cat=197

But, I'd much rather get a spacer from the local hardware store if it will work just as good without any sizing! I guess sizing it a bit wouldn't be a big deal though.


----------



## Lakeside53

davefr said:


> My 5/8" X 1/2" solid steel spacer worked great. The screen fit like a glove. In my experience there was no need for anything thinner then about .0625 wall. However maybe it's YMMV depending on actual screen tolerances.



Interesting... I never had any luck with 1/16 wall pipe fitting the screens. I even tried hammering some on... sure would make it easier ... Maybe I should check some more screens...


Buy your screen first, then head to the HW store and try one!


----------



## hawkfeather

I think I'll just order the tubing. I had a really nice MAPP torch but the thing overheats. I guess the orifice is stopped up and a new one costs almost as much as a cheaper MAPP torch... What brazing rod will work best with the MAPP? I read all the related posts but don't remember seeing this info?


----------



## Lakeside53

Pretty much any brass rod... it's all in the flux...


----------



## davefr

hawkfeather said:


> I can get a foot of that tubing for $1.70 from Online Metals here:
> 
> http://www.onlinemetals.com/merchant.cfm?pid=15520&step=4&showunits=inches&id=283&top_cat=197
> 
> But, I'd much rather get a spacer from the local hardware store if it will work just as good without any sizing! I guess sizing it a bit wouldn't be a big deal though.



If you get a spacer make sure it's solid vs. seamed unless you want to braze the seam. The Ace H/W I shop at had both. In the solid they had 1" and 1-1/2" lengths. I bought one of each but found the 1" a tad too short. I used the 1-1/2" but cut it to 1-1/4" and stuck it in about 1/4" on the short end.

My brazing skills suck so I didn't want to be brazing the very end of the tube.


----------



## Lakeside53

I'd try the spacer.. That tube will likely have $7 freight
Touch it with tapered reamer if it's reluctant to fit.


----------



## hawkfeather

Yeah... I forgot about that! I have a really good hardware dealer that has almost anything in a fastener you could need! Anybody know anything about MAPP torches overheating on the tip of the tube?


----------



## hawkfeather

Anyone know how much a 361 muffler costs new?


----------



## hawkfeather

And I assume the fastener covers just pop off and pop back on??


----------



## Lakeside53

hawkfeather said:


> Anyone know how much a 361 muffler costs new?



Close to $70...


----------



## Lakeside53

hawkfeather said:


> And I assume the fastener covers just pop off and pop back on??



yes....


----------



## Lakeside53

hawkfeather said:


> Yeah... I forgot about that! I have a really good hardware dealer that has almost anything in a fastener you could need! Anybody know anything about MAPP torches overheating on the tip of the tube?



Happens all the time when I use my propane torches on Mapp:hmm3grin2orange:


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## hawkfeather

Well, I better not mess mine up when I do the mod then! LOL


----------



## Trigger-Time

hawkfeather said:


> Anyone know how much a 361 muffler costs new?



I bought a used one, ebay $15, used it to mod and put the new
one up for safe keeping.

No screen though.


----------



## Tzed250

Trigger-Time said:


> I bought a used one, ebay $15, used it to mod and put the new
> one up for safe keeping.
> 
> No screen though.




That looks almost factory...


----------



## davefr

Here's another option I stumbled onto:






Husqvarna used bolt on muffler outlets on 281's and they're available for <$20 w/screen. I have one on order for my 7900 but it might also fit 361 along with other saws.


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## Lakeside53

You can also get a very cool looking BR600 outlet (Square tube), but... all these suffer from the problem of a low spark arrester area to outlet.. Prone to debis accumulation affecting performance. Also, I'd want to thicken up the metal behind the screws - the muffler metal is very thin.


----------



## Haywire Haywood

Yep, that's what several saw builders use, they mostly weld them on from what I've seen. The one I had didn't like the screen though, broke it off and spat it out.

Ian


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## woodyman

I thought I saw that $20.00 muffler outlet for the 281 on a ported muffler I was looking at for my 359 and they wanted like $100.00.The muffler was new with the added outlet but I dont know if they drilled or gutted the inside out.It was too much for me so I did my own.Will have pics as soon as I can get ahold of camera again from sister.


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## Haywire Haywood

If you do use that one, don't make the mistake of just hacking out the biggest square the deflector will cover. It will likely be too much unless you're installing it on a big saw. The output area of that one maxed out is twice what the Lakeside type mod has.

Ian


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## jrslick22

*I just couldn't help myself.*

Hi, first of all let me say thank you for such an informative an well kept forum (this is my first post) i have enjoyed the last few months of reading.

After reaching the end of this and a few other threads i went and brought my self my first chainsaw, i decided to get a Dolmar top handle, i enjoyed using my new pencil sharpener on meth so much i ran out an brought a used 372 XP as well, which well to say the least was a 'popcorn maker' until i did a bracket muffler mod now my mates are calling it a noodle maker!

after grinning so much due to my new found pleasure i brought a used husky 36 which i felt would have a bit more guts on the ground without overdoing my back (yes of course i have a bad back as well).

I then stopped at Bunnings (like home depot) and couldn't help but but another POS top handle to keep around as my loner, it was about $70 US and i love to "issue" it to my mates with a blunt chain - also a great source of the somewhat permanent grin i now have.

My wife is not exacly thrilled as this all sort of happened over the space of about 4 or 5 weeks - what can i say i only know one speed! i guess what im trying to say is i guess you guys ot to have some type of disclamer on the site that warns people of the potential addiction, seeing my freshly ported 372 make noodles out of pine was like witnessing the birth of my first child, i would of shed a tear if it wasn't for the stupid looking grin from ear to ear.

so yeh thanks a lot guys, my addiction will probibly end with astranged children and a devorce but thanks anyway.

now for my questions:
1. How come this thread ant a sticky? great tread four paws
2. As i know nothing about tuning two strokes i need a little help with the final touches on my 372, when i hit top end it sort of has this flattning out sound, i have played around with the H fuel adjusment including grinding off the limiters as other s have done but do not seem to be able to find what i beleive is the sweet spot. i have noticed that if i take her about a quater turn in (clock wise) she really starts to increase in revs as i understand though this is the lean side, if i take her out about a half a turn from that point she starts running ruff so i have her set a little over half way between the two points on the out or rich side (assuming anti clockwise for richer) with the idea that i am better off running to rich than to lean.

i have read the link: http://web.archive.org/web/20051018212959/www.madsens1.com/sawtune.htm
and have downloaded the workshop manual but am still not 100% sure what i am doing and would feel like my wife has file for devorce if i were to cook my 372.
please help.

thanks.


----------



## Urbicide

Hey Junior, welcome to AS. Great 1st post. Yes, 4 Paws does make some excellent tutorial threads. Does your 372XP have a limited ignition module? These make tuning more difficult and you can damage your saw if you lean it out too much. The limited modules are blue in color. It will also have the maximum RPM rating engraved on the side of the module. The unlimited modules are black in color. The black module is the one that you want. Another important tool is a tachometer so that you can accurately set the carb. Seeing numbers on the tach is safer than trusting your ears, especially if you are new at this or if your hearing ain't what it used to be. 

Be sure to compensate your better half with something she really likes when ever you buy another saw. This might get to be more expensive than your saws depending on what makes her happy.

Now as far as getting the smile off of your face. Just keep a lemon in your pocket and take a bite out of it as needed.


----------



## jrslick22

Urbicide said:


> Hey Junior, welcome to AS. Great 1st post. Yes, 4 Paws does make some excellent tutorial threads. Does your 372XP have a limited ignition module? These make tuning more difficult and you can damage your saw if you lean it out too much. The limited modules are blue in color. It will also have the maximum RPM rating engraved on the side of the module. The unlimited modules are black in color. The black module is the one that you want. Another important tool is a tachometer so that you can accurately set the carb. Seeing numbers on the tach is safer than trusting your ears, especially if you are new at this or if your hearing ain't what it used to be.



mine is blue, where do i get a black? would keeping the blue still be an option if tuned properly ie by the dealer, or will the black be better in the long run/better performance?


----------



## Urbicide

The blue module is usable as long as you stay below the RPM cutoff point. This is where a tachometer really comes into play. The black module is much more versatile and desirable. The module that fits the 372XP also fits over 20 other Husqvarna models. You might be able to find a used one from a donor saw. Bailey's carries an aftermarket unlimited module. It might be cheaper to order one through them with the exchange rate being what it is than it would be to procure one locally.

http://www.baileysonline.com/itemdetail.asp?item=NLM+372&catID=109


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## jrslick22

So i should be attempting to stick to the recommended 13500 rpm once i have the black unit, i assume the idea behind the upgrade is to make her rev more?

$42 is hard to beat, i might run it down to the husky shop to get it up and running until the ignition unit arrives.


----------



## Urbicide

The blue module obviously prevents the saw from turning over 13,500 RPM's. (The leaner the mixture the faster the saw turns.) It does not prevent you from leaning out the fuel/air mixture to the point that you damage the piston and/or the cylinder. The saw simply will not spin faster than the cut out point built into the module, regardless of how lean the "H" screw is turned. Some folks adjust their carbs so that the saw is running approximately 200 RPM's below the cut-off point. That way you know that you are safe. The black coil will not mask an improperly adjusted carb. You lean out a saw with a black module and it will scream. A tach is a handy tool to have and it is even more critical to use one when setting up a saw with a limited ignition module.


----------



## Nailsbeats

lectrocrew said:


> My dual port cover (pn 1122 140 0800) came in at my Stihl dealer but not my gasket so I had to use high temp RTV sealer for now to get my saw running to cut all these trees the storm has blown down. I'll go back and put the gasket in there when I get it.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> I tuned the carb to the new exhaust and cut some wood. WOW, this saw gives me a virtual adrenaline overdose.




That's some sweet work man. I just finnished my second 660's muffler mod. I just open the side vent all the way to that slit and leave the stock front muffler cover on. I also chop the front of that cage off, I should plasma them totally off like you did. Longterm, I probably will. Again, nice job, looks really nice. Really makes em' cut don't it.


----------



## jrslick22

Urbicide said:


> The blue module obviously prevents the saw from turning over 13,500 RPM's. (The leaner the mixture the faster the saw turns.) It does not prevent you from leaning out the fuel/air mixture to the point that you damage the piston and/or the cylinder. The saw simply will not spin faster than the cut out point built into the module, regardless of how lean the "H" screw is turned. Some folks adjust their carbs so that the saw is running approximately 200 RPM's below the cut-off point. That way you know that you are safe. The black coil will not mask an improperly adjusted carb. You lean out a saw with a black module and it will scream. A tach is a handy tool to have and it is even more critical to use one when setting up a saw with a limited ignition module.



Thanks so much for taking the time to explain you have really helped.

I will order a couple of the black units and a tacho, this way i am able to look after my own equipment without bending over for the husky dealer.

According to the info i have gathered thus far putting a whole in the muff will allow the carb to push more air thus requiring more fuel or a richer mix, but the leaner the mix the higher the revs (must be a 2stroke thing). As you have explained (and if i understand correctly) the idea is to be running higher revs with a richer mix by getting rid of the 13500 ign limiter.

So if ive got this correct:
1. Order parts 2. Fit parts 3. Attach tacho 4. Adjust fuel air mix until desired tech reading 5. Fit 32" bar and chain 6. Spray mates with noodles and popcorn while yelling thats a cute saw you've got there, your wife must really like it!

Or does the new ign unit have adjustments for limiting the revs?
What would the desired rev count be for a 372?

Thank you very much.


----------



## jrslick22

Anyone else following this tread see also

tuning you saw:
http://www.arboristsite.com/showthread.php?t=73107&page=2&highlight=muff+mod[/url]
http://www.arboristsite.com/showthread.php?t=46721&highlight=muff+mod

more on RPM
http://www.arboristsite.com/showthread.php?t=64963&highlight=muff+mod

For more answers to the same sort of questions.


----------



## lectrocrew

Nailsbeats said:


> That's some sweet work man. I just finnished my second 660's muffler mod. I just open the side vent all the way to that slit and leave the stock front muffler cover on. I also chop the front of that cage off, *I should plasma them totally off like you did*. Longterm, I probably will. Again, nice job, looks really nice. Really makes em' cut don't it.


Thanks Nailsbeats.
Note that I only used the plasma cutter to separate the cage into sections that would enable those sections to flex on the factory spot welds. Then the sections came loose from the factory spot welds with very little effort and absolutely no metal damage to the muffler housing. The Plasma arc will blow a hole in the muffler housing very easily if it gets close to it. Don't try to cut the spot welds that are holding the cage to the housing. 
Also, if you do completely remove the cage, this will leave only the thin metal that the housing is made of to support the entire muffler assembly where it bolts to the cylinder. This would be a weak point and over time will likely break due to vibration, metal fatigue ect. That's why I welded the stainless plate in place of the cage - for support. Are you planning to weld in a support plate also on your project?


----------



## Nailsbeats

lectrocrew said:


> Thanks Nailsbeats.
> Note that I only used the plasma cutter to separate the cage into sections that would enable those sections to flex on the factory spot welds. Then the sections came loose from the factory spot welds with very little effort and absolutely no metal damage to the muffler housing. The Plasma arc will blow a hole in the muffler housing very easily if it gets close to it. Don't try to cut the spot welds that are holding the cage to the housing.
> Also, if you do completely remove the cage, this will leave only the thin metal that the housing is made of to support the entire muffler assembly where it bolts to the cylinder. This would be a weak point and over time will likely break due to vibration, metal fatigue ect. That's why I welded the stainless plate in place of the cage - for support. Are you planning to weld in a support plate also on your project?




I think other Stihls are just like that with no cage and no support there. I could certainly TIG one in there, it can't hurt. When I cut the front of my cage off I actually cut the whole plane of that surface off, so you are left with two sides, a bottom, and the divider. I may be able to snap it all off the way it sits. I thought about that when I was doing it, but I wasn't by the tig and didn't want to find out I needed the support, so I left it. I don't suspect it is impeding flow much.


----------



## lectrocrew

Nailsbeats said:


> didn't want to find out I needed the support, so I left it. I don't suspect it is impeding flow much.


Looking back, I think my first mod of just cutting the front out of that cage and also opening up the outlet supplied plenty of flow, and I do not believe completely removing the cage gave the saw any more power. Sure, with the cage removed there's no doubt about minimal exhaust restriction, but I think there's plenty of flow for the stock 660 with the cage in place. The main restriction that causes power loss is the small final exhaust output opening. In my opinion, with that area opened up, you should see all the power increase your going to see with a muffler mod on a stock saw. At the time I modded that muffler, I had plans to eventually do some extensive mods to the motor.


----------



## Nailsbeats

I concur doctor.


----------



## Tzed250

This should help...


----------



## funky sawman

Some guys state that the exhaust port should be 80% of the surface area on the cylinder head port. The question is what should it be with the increased back pressure of a spark arrestor screen?


----------



## Musclenut

All this muffler mod talk is making want to tinker with my 028. Before I start should I cut out the internal cage baffle or just drill bigger holes in it?

Also it seems some you like to take out the mesh screens and some of you strive to keep them. What's the best approch with the screens?


----------



## Net-Knight1

davefr said:


> The muffler just came out of the oven from being coated with exhaust paint:




Nice work!!!! Looks awesome!

   

:jawdrop:


----------



## forcedintoit

I just ordered my muffler from scott wojo and he sent me the pic today. Can't wait for it to get here!


----------



## SawTroll

Haywire Haywood said:


> Yep, that's what several saw builders use, they mostly weld them on from what I've seen. The one I had didn't like the screen though, broke it off and spat it out.
> 
> Ian




Sounds like a sensible saw!  

Joke aside, I think it was a good move to make this thread a sticky!


----------



## Haywire Haywood

forcedintoit said:


> I just ordered my muffler from scott wojo and he sent me the pic today. Can't wait for it to get here!



Doesn't look like he left you enough pipe to clip the screen on.

Ian


----------



## forcedintoit

The screen is on the inside



Haywire Haywood said:


> Doesn't look like he left you enough pipe to clip the screen on.
> 
> Ian


----------



## Haywire Haywood

Ah, then it's not a Lakeside mod.... 

Ian


----------



## njforestfire

*Ok you saw tech's, what's your opinion?*

2 Strokes do rely on backpressure on the exhaust side to run properly. If they didn't require it then why are there tune pipes on go-karts and dirt bikes and hot saws?!?!?! With this said, my muffler mods are at 80% of the exhaust port area from the jug. Run GREAT! I have read earlier in this long post about numbers from 85% to 120% of the port opening...which to me would be WAY too big to supply any backpressure. Has anyone done any studies or testing of different size openings to find what might be the optimum size? Of course one would need a base line test saw and consistantly document all changes and performance readings.


----------



## ezs

I agree with you about a Tuned System. It also is true that an expansion chamber is key in 2 stroke performance, not a baffled exhaust. So a simple hole may do something, but not like an open chamber to become a pipe. Maybe a large exit is for that restraining system in the first place? :monkey:


----------



## bigjake

anyone in the northern cincinnati area i have 2 metal lathes a small mill a tig
welder with hi frec .I do alot of metal fab so if anyone needs help or use of
the shop let me know i didnt relize how simple this was .Dam now i wish i
had a 460 instead of a 441 .Would a muffler mode work on the small saws
like a 025 .or is it for pro saws .


----------



## Haywire Haywood

Should work with any saw, just have to adjust the size of the extra port to the size of the engine.

Ian


----------



## biggenius29

I just got a 460 a month or so ago and am wanting to do a muffler mod on it, I am awful at math, so what size hole should I put in the muffler for the 85%, or would this saw be better with a 100-125% hole?


----------



## Lakeside53

Easier to just buy the factory dual port muffler front.


----------



## Lakeside53

funky sawman said:


> Some guys state that the exhaust port should be 80% of the surface area on the cylinder head port. The question is what should it be with the increased back pressure of a spark arrestor screen?



If it's a stihl the screen has little effect - it's many times the area of the outlet.


----------



## psych038

Musclenut said:


> All this muffler mod talk is making want to tinker with my 028. Before I start should I cut out the internal cage baffle or just drill bigger holes in it?
> 
> Also it seems some you like to take out the mesh screens and some of you strive to keep them. What's the best approch with the screens?



i took the muffler of my 028 wb last night and it has very little baffle no sceens and a huge hole.. not gunna touch it that thing already screams.
did some work to my 038 super and dont think i did enough. maybe ran a little better but not the difference everyone is talking about. i think i'm gunna open the baffles up some more... maybe cut the one after the sceen and before the exit port all the way out. maybe the sceen is chocking it?? i put my extra holes in the same area as the stock port because ther was already a sceen there. muffler is the single port 038 unit. scared of f'ing it up.


----------



## MnSam

psych038 said:


> i took the muffler of my 028 wb last night and it has very little baffle no sceens and a huge hole.. not gunna touch it that thing already screams.
> did some work to my 038 super and dont think i did enough. maybe ran a little better but not the difference everyone is talking about. i think i'm gunna open the baffles up some more... maybe cut the one after the sceen and before the exit port all the way out. maybe the sceen is chocking it?? i put my extra holes in the same area as the stock port because ther was already a sceen there. muffler is the single port 038 unit. scared of f'ing it up.



After picking up on this thread and reading it through, I was thinking the same exact thing as you as far as modding my 028WB exhaust. Went out into the garage (10 degrees but it didn't matter) and took the muffler apart. I saw the same as you, no baffles and already plenty of flow. I read part way into the thread that the older saws will not benefit much from a muffler mod because of this. And like yours mine already screams. I am now looking for a good priced used "experimental" saw solely for testing purposes.


----------



## warlock1944

*Flow Calculations*



timberwolf said:


> 10 small holes of the same area as one big hole will flow less because restrition to flow is highest along the edge of an orfice, more small holes has a longer edge than one big hole of the same area.
> 
> However scavenging can be affected by too big of a single direct opening allowing fresh charge to escape the confines of the muffler, so in a way smaller openings cold be incorporated to minimize losses, but it is going to be complicated as how much of the fresh charge gets out into the muffler and how much gets sucked back into the motor depends essentially on the scavenging efficiency and design of the saw, how dilluted the escaping fresh charge becomes after entering the muffler depends on the shape and design of the muffler. Realy need to look at the flow and mixing of charge and exhaust in the muffler. The more the fresh charge dillutes into the exhaust, the less can be recouped. Run a saw with no muffler at all, and it has less power than with a typical muffler as too much charge is being lost to the suroundings and not recovered during scavenging.
> 
> The area of 10 small holes will need to have a greater area than one big hole to give the same flow and back pressure.



A measure of the flow capability (flow less than supersonic) is the hydraulic radius which is the wet perimeter / flow area. To make them approximately equal in flow characteristics set up a proportion :

wet perimeter(1)/area(1) = wet perimeter(2)/area(2) and solve for the one you want. 

Very easy if you set up an excel sheet you can play what if until you get the the number and size holes that works best.


----------



## timberwolf

Yes that sounds good on paper, but flow bench tells otherwise. And even then a flow bench is steady state which still does not fully model the more dynamic real world where pressure and temperature, density and velocity are swinging all over the place 200 times a second.

What I am saying it there is more to the ideal outlet size than one would think. And I have doubts about the wet perimiter theory as far as practicle application to an exhaust outlet port.


----------



## MnSam

I'm guessing there aren't too many, if any, pictures of a Wild Thing on this site. So I'll throw this in here (with a Stihl in the background for support). I was just practicing the muffler mod concept on this before I attacked anything important. I haven't started it up yet, too late at night for the neighbors. They say you can't polish a turd, but I'm trying. Oh, and disregard the welded portion at the bottom/center portion of the muffler, I was going to cut-out there but moved it.


----------



## limelakephoto

That wild thing looks not to bad ! Nice work. I opened the muffler on my worn out 12 year old poulan and adjusted the carb and it is ready for another 12 years, now it has more snot then when i bought it.


----------



## injun joe

Haywire Haywood said:


> I read somewhere online recently that you could braze with MAPP gas. So I bought a bottle of that and a general purpose 1/8" brazing rod with the flux coating. I had my doubts about it getting hot enough, so the first thing I did was see if it would melt the rod. It melted the flux off and that was all it did. $10 gone to waste on that effort.
> 
> Ian



well i have put it my fair share of welding and i can't figure out why you couldn't braze this mapp gas burns a little less than acetylene and acetylene burns at 6000 degrees it could have been a lot of things wrong brazing rod improper hose pressure wrong size tip the list is endless.


----------



## warlock1944

*wet perimeter*



timberwolf said:


> Yes that sounds good on paper, but flow bench tells otherwise. And even then a flow bench is steady state which still does not fully model the more dynamic real world where pressure and temperature, density and velocity are swinging all over the place 200 times a second.
> 
> What I am saying it there is more to the ideal outlet size than one would think. And I have doubts about the wet perimeter theory as far as practicle application to an exhaust outlet port.



Hydraulic Radius does indeed work as far as equating one tube size to another as long as the flow is sub sonic where the Reynolds number is linear. I did not offer anything about a percentage size for the flow area.

Two stroke tuning utilizes the exhaust standing wave to scavenge the combustion chamber allowing more charge and better efficiency. Reducing the backpressure (better flow) can in some cases (depending on port timing) hinder power output or more likely change the point at which peak power is made. This is why hot saws and ringy ding bikes have expansion chambers.

The knowledge is out there to calculate all of these factors but in today's world they do not, after all the cheapest silence is is the Idaho silencer which is why opening up mufflers works in most cases.


----------



## timberwolf

Yes for a tube, for an orifice in thin plate no.

Problem is in smaller holes the thickness of plate in relation to the diamiter of the hole changes the coefficient of discharge to a greater extent than how much the wetted perimiter effects the total flow.

When the radius of the hole is only a few times greater than the tickness of the plate the coefficient of discharge starts to head more towards 0.75 instead of 0.60.

I even found that a thin slot with the same area as a circle flowed as much or more than the circle. in theroy looking at the wetted perimiter this should not be. However an orifice shaped as a thin slot in thin plate is squeezed between two edges that have a high relative thickness compaired to the width of the opening raising the coefficient of discharge. 

I would not have though this would be, more wetted perimitter should be less flow from a simple logical prespective, but like I said putting this to test on a flow bench has taught me otherwise. In some cases esp in smaller openings coefficient of discharge is a bigger factor than wetted perimiter.


----------



## BigSawMan

Well I modded the 385, I drilled 4 1/4" holes spaced out evenly on the front of the muffler. I just drilled through the first piece, the outside of the muffler, should I drill out the inner baffle as well?

The coefficient of flow talk about the hole size vs the thickness of the metal makes me think that I should open the holes up a little bit more because they are smaller?

What do you guys think?


----------



## timberwolf

Four 1/4 inch holes is very conservative, that sort of opening would more suit a saw half the 385 size.

Go with a 3/8 drill, thats still under 0.5 in2 and is likely close to 100% or less of the stock exhaust port area.

Often the muffler insides are where the real restriction is.


----------



## BigSawMan

Well I'm going to drill out the holes to 3/8ths, should I drill through the second plate on the inside?

Would four 3/8ths holes be too much? thats equiv to 1.5" hole.


----------



## timberwolf

No 4 holes 3/8 each is fine, it is not equal to a 1.5 inch hole.

The area of a circular hole is half the diamiter x half the diamiter x 3.14

0.375 /2 = 0.1875 

0.1875 x 0.1875 x 3.14 = 0.11 in2

0.11 in2 x 4 holes = 0.44 in2

Four 3/8 holes is equal size wise to a single 3/4 inch hole. A circle twice the diamiter has 4 times the area. A 1.5 inch hole then would have 4 times the area of four 3/8 holes.

Don't forget to reset the carb, bigger exhaust holes and it will need more fuel from richer jetting.


----------



## BigSawMan

Ahh, thanks for the math lesson lol, I thought that didnt sound right when I did the area in my head...

Will do.


----------



## Dowclan

*036 -Muffler Mod*

Hey guys, I've got a 036 and was wondering if it was worth the effort of muffler mod. I've read how it's the newer models that really benefit from the mod and I couldn't determine if the benefits would out weigh the cost/labor put into the effort. Thanks in advance for your thoughts.
Dave


----------



## BigSawMan

Do it!

Do a search for 036 or stihl muffler mod and see what comes up, I'm sure your not the first to do one. 

How advanced do you want to go, just drill some holes or cut and weld in new tubing etc..?


----------



## Dowclan

*Bsm*

BigSawMan:
Thanks for the feedback. Yeah, I read nearly the entire thread. Heavy reading for sure. There's a section written specifically for the 361 owners. But since that is a newer saw than my 036, I wasn't sure if the outcome, would be as rewarding. I may consider it after I finish cutting some more wood this year.


----------



## GrizzlyAdams86

After reading this entire thread, the gears are turning in my head. I just got my 288xp going and would muffler modding/porting this be worthwhile? It has the larger dual felling spikes with the A/V bracket mounted to the muffler and was made sometime in the 90's. I also have a early Husky 61 (has the white top cover) and a 137 for practice/fooling around with if I decide to mod the 288. I primarly just cut firewood although in my area we've been losing some bigger oak, elm, and cottonwoods to disese, etc. Any and all comments are welcome. Thanks!

Husqvarna: 137, 61 (in pieces-yet), L65, 288xp, 2100CD
McCulloch: Mac 2-10 (won't stay running-rainy day project)


----------



## (WLL)

after failing several times trying to get a original wojo muffmodd i had to make my own. i thought i posted here a while back, but cant find it with search. this is what i came up with.




the biggest problem with the 066 is the carb needs more more fuel and the Onegin needs more air. if u open every thing up the rpm's will scream. imo the stihl is a better saw to work with and has a better/stronger chassis than the husky,better air flow than the husky,better jugs than the husky,better,ect,ect,. they are both top stock sawz to work with in wood,but stihl is the only saw for me. *DONT BE A:monkey: iiMODDED SAWZ ARE DANGEROUS!!*


----------



## SawTroll

I actually have a Andy made muffler that look a bit different - pics will show up some time, when I have put it on the saw.

Hard to get a decent test log here, the way my foot is - have to go into the woods, and the ancle is not stable......:censored:


----------



## skinnykid02

Four Paws said:


>



thats looks real nice! Will someone do that to mine??


----------



## K9-Handler

injun joe said:


> well i have put it my fair share of welding and i can't figure out why you couldn't braze this mapp gas burns a little less than acetylene and acetylene burns at 6000 degrees it could have been a lot of things wrong brazing rod improper hose pressure wrong size tip the list is endless.



The givaway is that he said it cost him $10.

I braze with Oxy/Mapp, as I'm sure you do, injun joe. I think he just went out and bought one of the hardware store yellow mapp cylinders and thinks it would get hot enough to braze. It won't.
All those things are good for is soldering pipe a little quicker than propane would do.


----------



## Metals406

timberwolf said:


> Yes for a tube, for an orifice in thin plate no.
> 
> Problem is in smaller holes the thickness of plate in relation to the diamiter of the hole changes the coefficient of discharge to a greater extent than how much the wetted perimiter effects the total flow.
> 
> When the radius of the hole is only a few times greater than the tickness of the plate the coefficient of discharge starts to head more towards 0.75 instead of 0.60.
> 
> I even found that a thin slot with the same area as a circle flowed as much or more than the circle. in theroy looking at the wetted perimiter this should not be. However an orifice shaped as a thin slot in thin plate is squeezed between two edges that have a high relative thickness compaired to the width of the opening raising the coefficient of discharge.
> 
> I would not have though this would be, more wetted perimitter should be less flow from a simple logical prespective, but like I said putting this to test on a flow bench has taught me otherwise. In some cases esp in smaller openings coefficient of discharge is a bigger factor than wetted perimiter.



TW, so you're saying a slot port (as pictured below) would flow better than a round pipe?


----------



## Lugnutz

ok to be honest I haven't looked to find spark aresting mesh..thought it would be easier just to ask the people that know what they are doin...so..where do you find this stuff???


----------



## Lugnutz

*Finally found it*

After reading all 15 pages I found where to get the mesh. Took the muffler off my WildThang and found out I don't need any mesh, drilled 6 holes in baffel on the underside and a 3/8" hole in the front cover. Seems purdy snappy now and with some tinkering with the carb it idles nice once again.

My only question concerns how to tell if it is burning lean. I adjusted the hi end to max with the red plastic cap still on it. Am I going to only be able to tell by looking at the spark plug? Also how do you pull the caps off if you need to go further with it?


----------



## Urbicide

The limiter caps have "stops" which obviously block movement of the screws past a certain range. You will need to remove the actual tabs with a dremel, razor knife, or heavy duty nail clippers. You do not need to remove the whole limiter cap. The safest way to check RPM's is by using a tach. Madsen's has a nice section on saw tuning with some sound wave files to give you an idea of how a saw should sound.
http://www.madsens1.com/saw carb tune.htm
Scroll down to #6 under Carburetor Adjustment Procedure and you will find the high speed adjustment file.


----------



## maytagman

I am in a area that I am not worried about using a spark screen. If I did this mod and didn't want to use a screen would I use a smaller dia. pipe since you must figure the screen creates a certin amount of restriction?


----------



## Lakeside53

You can.... but why not just run a screen to deep the junk out...?

As for resizing... you can go down to 14mm if you like, but it works pretty well at 16 with no screen. Idle isn't as nice, but it's no big deal.


----------



## maytagman

Ok, ready to drill into the muffler in the next day or two. I am sorry for asking, i did re read the post, but it is late and I may have missed it. I have the 1 1/2" spacer. How long to you want it to be after the 45 degree cut. I don't have the screen yet, or I could figure it out. I thought I remembered something about 3/4" but was that for the long side or short side measurement? I havent really figured out how I am going to make the cut. Maybe freehand with a cutter wheel on a 4" grinder then even it out on the side of a bench grinder wheel? If I had a longer tube I could cut the angle with a chop saw, but the 1 1/2" piece isn't the best to work with. I am going to guess the wouldn't have to be that exact. Any tips would be appreciated.

Thanks guys


----------



## Lakeside53

I make the long side about an inch now. You want 3/8 to 1/2 inch (MIN) on the short side. Push the long side butt right up to the muffler seam. A vice and a fine (32tpi) hacksaw makes easy work of tube. Finish up in a grinding wheel.

One trick to cutting tube is to put a tight wood dowel though it. Then you can clamp easier in a conventional vice.


----------



## maytagman

Thank you


----------



## Martinm210

Thanks to this thread, I went ahead with my muffler mod tonight on my 066BB build.

I went with a single port in the stock location. It's really easy on this muffler because it already has a huge spark screen box for this. All you have to do is carefully grind away.

The other thing I did was spending alot of time carefully port matching at the cylinder head. After finishing the exhaust port I cut out a template with tape and then ground the gasket to match perfectly. Then I transfered this to the muffler opening for a perfect match.

Anyhow, pretty darn easy on this one, just takes a little grinding.

I did some quick and dirty flow restriction check with and without the muffler cover on and it seems the internal baffle system don't create much of any restriction. The big restriction was in the muffler external port size and after this mod, that's much much better. So I chose to keep the internal baffle figuring that it acts as sort of a flow spreader to allow more even flow out the exhaust port and should help keep noise at bay a little too.

I didn't measure precisely, but visually it looks to roughly match the same amount of area that the carb inlet, so I'm happy with it.:greenchainsaw: 







Thanks for all the great tips in here..


----------



## (WLL)

*100cc B.B. 4 port stroker with a tampered ignition*

this baby kicks so bad i had ta swap the oem rubber mounts with pollyurathane so the mounts stoped ripping apart. she runs on 110 cam-2. im keeping the ignition details a secret


----------



## Urbicide

(WLL) said:


> this baby kicks so bad i had ta swap the oem rubber mounts with pollyurathane so the mounts stoped ripping apart. she runs on 110 cam-2. im keeping the ignition details a secret



Wow! Hate to use the term "Wild Thing" but that is one wild-looking saw!:chainsawguy:


----------



## (WLL)

here 2 custom wild things


----------



## Work Saw Collector

*Here is my first mod a scrench pipe*

My 036 with a scrench for a pipe, I cut it at a angle and used the screw driver part as a brace. Now maybe cutting stumps at the dirt it won't get as hot. There is a smaller pipe running into the muffler welded on the inside this one slid over it and welded on the outside. It sure sounds good.


----------



## (WLL)

supercabs78 said:


> My 036 with a scrench for a pipe, I cut it at a angle and used the screw driver part as a brace. Now maybe cutting stumps at the dirt it won't get as hot. There is a smaller pipe running into the muffler welded on the inside this one slid over it and welded on the outside. It sure sounds good.


now thats trik!!


----------



## Work Saw Collector

thanks


----------



## KD57

If the cover ever sticks to the muffler and you can't get it off, put a wrench on her, lol.


----------



## RON58

What is "four stroking" that you all talk about when tuning a saw?


----------



## Lugnutz

*yeah...what he said*



RON58 said:


> What is "four stroking" that you all talk about when tuning a saw?




+1


----------



## Metals406

Saws being tuned...

L side-- http://www.madsens1.com/setlow.wav

H side-- http://www.madsens1.com/sethi.wav


----------



## rngrchad

*372xp Modded tonight.*

Saw: 372xp
After reading the various threads of modded exhausts, I thought I would
spend my snowy evening in the garage.
Precut a few pieces of 3/4" steel pipe (available at lowes) with various angles to see which one would work the best:




Traced the outlet on the muffler while mounted on the saw:




Drilled Hole:




I de-burred the outlet: 




Brazed The pipe on(Had to call friend to Hold pipe on while I "tacked it". Prior to brazing, I ran the wire-wheel over the hole to remove black paint.




Lightly sprayed the Exhaust with flat black stove paint and re-assembled. Will get a screen for it next time I make it to local hardware.





I will adjust carb settings accordingly on my next outing.
Just want to say thanks for the great ideas AS.
This is my version of a "how to" for the 372xp. Hope it isn't too picture intensive!
-Chad


----------



## country boy

Looks awesome !!!!!!! Great work !!!


----------



## Metals406

I finally decided to muffler mod my Jonsered 670 SuperII last night. I wanted to document the whole thing... But my dang camera batteries died on me!:censored: :censored: 

I'll take a few more pics today, of the finished mod.






This is the factory outlet, which I TIG'd closed.

























I cut the muffler with my Dremel and a cutoff wheel. Then I used a single cut bit to radius the ends.


----------



## Metals406

As a side note... This is my buddy Rod's new saw. I had some remnant stainless steel, so he decided to make some custom dogs.


----------



## FELLNORTH

Does Anybody Have Any Pics Of A Dolmar 7900 Muffler Mod?
Anything Would Be Apreciated
Thanx


----------



## rngrchad

Nice videos Metals. That saw sounds uber mean! What length bar? 32?
I'll have to get some video of my 372 as soon as the temperatures get above the negatives.


----------



## Metals406

rngrchad said:


> Nice videos Metals. That saw sounds uber mean! What length bar? 32?
> I'll have to get some video of my 372 as soon as the temperatures get above the negatives.



It's a generic Oregon 28"... When it goes to guide-bar heaven... I have my sights set on a Sugihara, or Oregon reduced weight.

Yeah, you guys are getting hammered over on the east side of the country. We've actually gotten a break from the cold and snow, and it's been in the 40's during the day. BRING ON SPRING! I'm ready!


----------



## Metals406

country boy said:


> Looks awesome !!!!!!! Great work !!!




He did a good job!


----------



## rngrchad

Metals406 said:


> It's a generic Oregon 28"... When it goes to guide-bar heaven... I have my sights set on a Sugihara, or Oregon reduced weight.
> 
> Yeah, you guys are getting hammered over on the east side of the country. We've actually gotten a break from the cold and snow, and it's been in the 40's during the day. BRING ON SPRING! I'm ready!



Hehehe, you and me are on the same page. I am wanting a Sugihara 32" really bad. I saw Tree Slingr's videos of his sugihara bar, and now I want one even more. Dam AS. I'm hoping after the muff-mod that the 372 will turn a 32" bar w/ full skip semi-chisel carlton really well.


----------



## Metals406

rngrchad said:


> Hehehe, you and me are on the same page. I am wanting a Sugihara 32" really bad. I saw Tree Slingr's videos of his sugihara bar, and now I want one even more. Dam AS. I'm hoping after the muff-mod that the 372 will turn a 32" bar w/ full skip semi-chisel carlton really well.



I got that 670 with full skip... Wasn't necessary. It pulls full comp just fine. I'd try a 32" on your 372 with full comp and a 7-pin first... And if it's too slow, switch to full-comp.


----------



## imanoob

Do you guys think it's worth it to mod a 025? The saw will be used pretty much for just firewood, and cutting limbs and stuff. I have researched the 025 and most people say it is better for just bucking wood because it's real light but doesn't have a lot of power. Would I be better to mod it a little or leave it? I am also not sure if it has a fully adjustable carb yet because I haven't gotten the saw. Will hopefully have it in my hands on friday!

Thanks


----------



## CHEVYTOWN13

*Very very nice indeed.*



> I cut the muffler with my Dremel and a cutoff wheel. Then I used a single cut bit to radius the ends.



Extremely nice cuts BROTHER METALS406!


----------



## JONSEREDFAN6069

here's the twin outlet on the old 670 champ


----------



## spankrz

imanoob said:


> Do you guys think it's worth it to mod a 025? The saw will be used pretty much for just firewood, and cutting limbs and stuff. I have researched the 025 and most people say it is better for just bucking wood because it's real light but doesn't have a lot of power. Would I be better to mod it a little or leave it? I am also not sure if it has a fully adjustable carb yet because I haven't gotten the saw. Will hopefully have it in my hands on friday!
> 
> Thanks



i modded my 250, and it helped a lot. i drilled about a 1/4 inch hole behind the little plate that bolts on in front of the muffler. that way when i am carving at a show, i can put the plate back on and the saw is quiet again.


----------



## Urbicide

imanoob said:


> Do you guys think it's worth it to mod a 025? The saw will be used pretty much for just firewood, and cutting limbs and stuff. I have researched the 025 and most people say it is better for just bucking wood because it's real light but doesn't have a lot of power. Would I be better to mod it a little or leave it? I am also not sure if it has a fully adjustable carb yet because I haven't gotten the saw. Will hopefully have it in my hands on friday!
> 
> Thanks



Welcome to AS. The older saws were not nearly as restrictive as today's saws are. Therefore, generally speaking, the results from muffler modding an older saw are not nearly as impressive as those results gained from opening up the muffler on a newer saw.You can open up your muffler and give it a try. You will need to time it in some wood both before & after modding to determine for sure if there are any realized gains. It will definitely sound louder and some equate loudness with power.:chainsawguy:


----------



## spankrz

well, here is a pic of my mild muffler mod on my 036 qs. i made a plate to fit, so i can put the stock one back on when i am carving.


----------



## imanoob

spankrz said:


> i modded my 250, and it helped a lot. i drilled about a 1/4 inch hole behind the little plate that bolts on in front of the muffler. that way when i am carving at a show, i can put the plate back on and the saw is quiet again.






Urbicide said:


> Welcome to AS. The older saws were not nearly as restrictive as today's saws are. Therefore, generally speaking, the results from muffler modding an older saw are not nearly as impressive as those results gained from opening up the muffler on a newer saw.You can open up your muffler and give it a try. You will need to time it in some wood both before & after modding to determine for sure if there are any realized gains. It will definitely sound louder and some equate loudness with power.:chainsawguy:



Do you know off the top of your head if this is a two-piece muffler?


What do you think is the best way to do it? Should I do like mentioned above and just drill a bigger hole or should I go all out and take all the baffles and everything out and put a screen in? 

Thanks for the help.


----------



## Metals406

CHEVYTOWN13 said:


> Extremely nice cuts BROTHER METALS406!




Thanks much!!



JONSEREDFAN6069 said:


> here's the twin outlet on the old 670 champ



Looking good!


----------



## JONSEREDFAN6069

Metals406 said:


> I finally decided to muffler mod my Jonsered 670 SuperII last night. I wanted to document the whole thing... But my dang camera batteries died on me!:censored: :censored:
> 
> I'll take a few more pics today, of the finished mod.
> 
> 
> 
> 
> 
> 
> This is the factory outlet, which I TIG'd closed.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> I cut the muffler with my Dremel and a cutoff wheel. Then I used a single cut bit to radius the ends.



VERY NICE!!!!!


----------



## CHEVYTOWN13

*The Doctor is in!*



> VERY NICE!!!!!



Sure is a purty cut.

I think Metals406 will AKA as THE DOCTOR


----------



## Metals406

CHEVYTOWN13 said:


> Sure is a purty cut.
> 
> I think Metals406 will AKA as THE DOCTOR



:hmm3grin2orange:


----------



## pmbou

*026 muffler mod*

I got this 026 last week and this site convinced me to mod the muffler so here goes. The baffle is a little different than other 026's on the site. The saw is date-stamped "S" which supposedly makes it a 1992 model, it's a non-pro.

Photo A shows the original four holes which are each 3/16" diameter (!) and located on the side of the baffle plate. I measured them, and believe me they really were that small.

Photo B adds two 3/16" holes on the top of the baffle.

Photo C shows the internal restrictor. It is a box that has twelve holes, 3/16" each, six on each side shown. After reading about another post, I decided not to remove the entire box. My reasoning was to maintain strength and direct heat flow towards the sides and bottom. 

Photo D shows the mod. I used a dremel with a 1/2" round stone bit and plunged right in to enlarge the openings. On the baffle plate, I used a cutoff disk on the dremel to make 2 triangles by connecting the 6 holes as shown.

Then I de-burred everything with a small bastard file to avoid loosing sleep over the chance of a piece of steel rattling into the cylinder. I washed out the metal shavings with soap and cleaned the outside with alcohol, then gave a few coats of high-temp paint and baked the parts in the oven at 500F till the smoking stopped.

Photo E shows the painted result.

I opened up the carb a bit and now it cuts like mad !!!
10 inch frozen poplar with a 3/8" square chisel isn't enough to even test it. 
I'm getting the itch to cut something down and make cookies out of it.
It's not even much louder but it sounds great, nice and poppy.
Thanks to all who posted how-to's.


----------



## spankrz

imanoob said:


> Do you know off the top of your head if this is a two-piece muffler?
> 
> 
> What do you think is the best way to do it? Should I do like mentioned above and just drill a bigger hole or should I go all out and take all the baffles and everything out and put a screen in?
> 
> Thanks for the help.



the muffler on my 250 is a two-peice muffler. however, my saw was built from spare parts. also, my saw never had a baffle in it from the first day i had it. im pretty sure that all 025's and older 250's are two-peice. i am also pretty sure the older ones didnt have a baffle.


----------



## spankrz

imanoob said:


> Do you know off the top of your head if this is a two-piece muffler?
> 
> 
> What do you think is the best way to do it? Should I do like mentioned above and just drill a bigger hole or should I go all out and take all the baffles and everything out and put a screen in?
> 
> Thanks for the help.



also, to answer your question, you should drill a new port at a spot that it will not blow exhaust on any plastic. be careful not to drill too big of a hole. remember, you can always drill it bigger. start around 1/4. on a bigger saw, start with two 1/4 inch holes.


----------



## imanoob

spankrz said:


> the muffler on my 250 is a two-peice muffler. however, my saw was built from spare parts. also, my saw never had a baffle in it from the first day i had it. im pretty sure that all 025's and older 250's are two-peice. i am also pretty sure the older ones didnt have a baffle.





spankrz said:


> also, to answer your question, you should drill a new port at a spot that it will not blow exhaust on any plastic. be careful not to drill too big of a hole. remember, you can always drill it bigger. start around 1/4. on a bigger saw, start with two 1/4 inch holes.



thanks for the tips


----------



## AR200

I am looking at doing a muffler mod on my jred 630. Do i have to close off the factory port or just leave it open also? Also how do you change the screen on these with it welded under a pipe or washer? Do you just clean it with a brush?


----------



## timberwolf

No harm in leaving existing outlet. Yes, you can clean the muffler screen with a brush, but if it's welded in it's not easy to replace without cutting and redoing the work.


----------



## Darton2

OK - I have searched and read abunch trying to figure out what the best size hole to open my 2171 muffler up too. I have seen the 80-85% rule but allot of guys put the double barrel 3/4 pipe or double barrel 1/2" pip coming out. Both are way more than that rule.

Who has done the modification and is happy with it on the 372 or 2171? What size did you end up with? 

I have a 6 month old saw that needs to breathe better but dont want to screw it up. Some guys mention that the saw doesnt idle well after the mod, I assume thats from going too far with the mod. Any advice?
:deadhorse:


----------



## timberwolf

Even on a bone stock 026 two 1/2 inch pipes will be fine. Problems start when the total area of the outlet is over about 125% of the exhaust port area measured at the port. 

I have saws here that will run fine with 150 to 200%. It ok if you are after every last bit of power, but it's stupid loud and hard on fuel.

That said, it easer to make a hole bigger than smaller, and most of the gains will be found in the first 75% increase in area after that it's a dimminishing return.


----------



## K9-Handler

*Shrek -- another version of a 7900 muff*

This is my version of the double-barrel mod shown in the beginning of the thread. It is for my Makita 6400/7900BB project.

I call this muff "Shrek". Do I need to explain farther? :hmm3grin2orange: 







On the saw:


----------



## AR200

I got my muffler mod done last night. The saw is a Jonsered 630 I left the existing port in the muffler and added this 5/8" dia hole. I ran it in some small stuff last night but can't wait till this weekend to put it in some bigger stuff to see if it made much difference. 




[/IMG] 




[/IMG]


----------



## (WLL)

K9-Handler said:


> This is my version of the double-barrel mod shown in the beginning of the thread. It is for my Makita 6400/7900BB project.
> 
> I call this muff "Shrek". Do I need to explain farther? :hmm3grin2orange:
> 
> 
> 
> 
> 
> 
> On the saw:


looks like the port is blowing right on the cutter hand


----------



## JONSEREDFAN6069

AR200 said:


> I got my muffler mod done last night. The saw is a Jonsered 630 I left the existing port in the muffler and added this 5/8" dia hole. I ran it in some small stuff last night but can't wait till this weekend to put it in some bigger stuff to see if it made much difference.
> 
> 
> 
> 
> [/IMG]
> 
> 
> 
> 
> [/IMG]



LOOKS GR8!!! what'd you use for screen?


----------



## K9-Handler

(WLL) said:


> looks like the port is blowing right on the cutter hand



It's not. Just a camera lens anomaly. The handle is well behind the exhaust flow (or at least half of it)! :hmm3grin2orange:


----------



## moose42

Well after reading all 18 pages of this thread I just had to go and do it to my saw. I decided to do it to my Stihl 064. The muffler was simple and seemed like the perfect choice. I started by opening the hole from a small half inch hole to about 3/4. I left the stock diverter on at first to see if there was much of a difference. WOW! After some test run (and re-tune) it ran awsome. I knew I had to make it just a bit better. So I took the stock diverter off (that stupid angle piece on the outside) so I can put a pipe on it. I went with a 3/4" conduit coupler. I cut an angle on it and then matched the hole to fit the oval. I didn't go all the way because the part that holds the screen gets in the way. I just welded the coupler on and then cleaned up the welds. The only thing I did the cage on the inside was drill 2 1/2" holes in the front. Gave it another re-tune and gave it a test. The saw is louder and a nice deep tone. The power increase is well worth the time and effort.


----------



## 820wards

Lugnutz said:


> ok to be honest I haven't looked to find spark aresting mesh..thought it would be easier just to ask the people that know what they are doin...so..where do you find this stuff???



I like your Wildthang...

Here is mine.

.17 Ackley Bee

jerry-


----------



## K9-Handler

*Big pipe*



moose42 said:


> so I can put a pipe on it. I went with a 3/4" conduit coupler.



Are you sure the Public Works Department isn't going to miss that piece of culvert pipe??? :hmm3grin2orange: :hmm3grin2orange: :hmm3grin2orange:


----------



## moose42

It's not all about the size of the pipe that matters, it is how well it works for ya!


----------



## AR200

> LOOKS GR8!!! what'd you use for screen?



Just some stainles steel screen we had laying around at work. I think we get it from mcmastercarr.


----------



## JONSEREDFAN6069

SOME PICS OF THE 630 MOD, JUST FINISHED TONITE



[/IMG][/IMG]


----------



## biggenius29

I just took my muffler of my 460 to do the mod. Do I drill out a hole in the cover of the muffler, or do I widen the side by the spark arrestor? I think it would be easyer to drill out the cover instead of the side of the muffler.


----------



## windthrown

Why are you modding a 460? You can go buy a dual port muffler cover from Stihl for that for about $30. Part number 1128 140 0801.


----------



## mole1982

What size hole do I drill in the muffler 1/2, or 5/8.


----------



## Lakeside53

Neither... drilled holes are round; you read the thread and it will tell you to trace around the angled pipe - a weighted oval....


----------



## windthrown

Lakeside53 said:


> Neither... drilled holes are round; you read the thread and it will tell you to trace around the angled pipe - a weighted oval....



But but but... where can I get a drill bit to cut an oval? Madsons? Harbor Freight? Does Stihl make one? :greenchainsaw:


----------



## weimedog

The one thing I see in these mods is emphasis on reduction of back pressure. Coming from the motorcycle world..and having tweaked, tuned, and raced motorcycles since the 1970's...I wonder if anyone has done research past less flow restriction and towards tuned mods. I realize expansion chambers are not practical but maybe improvements in other ways...maybe length of pipe or increased volume within practical limits. Possibly working the location of exhaust exit along with different length pipes to effect actual "tune". I think the newer Strato or X-Torq designs will require thought in that area from what I understand about their theory of operation.


----------



## Lakeside53

RTFM...

In any case, all drills will cut a "face oval" if drilled at an angle:greenchainsaw:


----------



## biggenius29

windthrown said:


> Why are you modding a 460? You can go buy a dual port muffler cover from Stihl for that for about $30. Part number 1128 140 0801.



I went to a dealer and was quoted $75. I just left it at that and figured for that I will mod it myself, and didnt bother asking other dealers. I will call another dealer tommorow.


----------



## Country1

Trigger-Time said:


> I bought a used one, ebay $15, used it to mod and put the new
> one up for safe keeping.
> 
> No screen though.


Not much has been said about this mod?? I assume it's not as good as Lakeside's??? I would be a lot simpler to do... No screen, but the "slits" wouldn't be that prone to letting in debris. Has no one else done this?


----------



## KD57

biggenius29 said:


> I just took my muffler of my 460 to do the mod. Do I drill out a hole in the cover of the muffler, or do I widen the side by the spark arrestor? I think it would be easyer to drill out the cover instead of the side of the muffler.



If you should decide to drill out the existing port, you will still be able to use the screen. A little harder than just drilling holes, but you get to utilize the screen. I have done it both ways, and can't tell any difference in performance, even tho one muffler has the baffle plate inside, and the other one doesn't. 
Can anyone tell me if the one w/o a baffle is an older model muffler, or just a different one?? Stihl has 3-4 different models listed for the 460.


----------



## JONSEREDFAN6069

the new and improved 630 muffler mod.



first post with the new camera.


----------



## Metals406

JONSEREDFAN6069 said:


> the new and improved 630 muffler mod.
> 
> 
> 
> first post with the new camera.



Looks nice!


----------



## AR200

> the new and improved 630 muffler mod.first post with the new camera.



Looks good and I bet it rips too. I like the angled pipes better than the straight. The straight looked like they would hit the log when cutting. What is the dia of the pipes. Conduit??


----------



## JONSEREDFAN6069

3/4 galvanized conduit. good eye. welded with a mig. then alot of grinding. i'm doing the 670 over again the same but with the bigger pipe. the original is crazy loud when you are bucking a big tree when the exhaust gets into the wood and bounces it back to ya. run half and half 108 race gas and 91 premium with lucas mix, smells gr8 but the loudness kills your ears even with plugs in. lol


----------



## ssiimmss

at the beginning of this thread, it is stated that you shouldnt exceed 80-85% of the exhaust port diameter, when porting your muffler. does anyone take the time to measure the exhaust port and do the math or are ya'll just eye ballin it an making sure that your below the 100% mark?


----------



## JONSEREDFAN6069

my 630 is definately just below the 100% mark but the 670 is about 115%
runs gr8 a little hard to idle buthas tons of power.


----------



## sno-man!

Country1 said:


> Not much has been said about this mod?? I assume it's not as good as Lakeside's??? I would be a lot simpler to do... No screen, but the "slits" wouldn't be that prone to letting in debris. Has no one else done this?



I would also like to know about this way. Looks very nice. How did you get the slits in the muffler?


----------



## Haywire Haywood

Thin dremel tool cutoff wheel and a screwdriver to lift the slots open... 

Ian


----------



## K9-Handler

ssiimmss said:


> does anyone take the time to measure the exhaust port and do the math or are ya'll just eye ballin it an making sure that your below the 100% mark?



Always. It's given me an opportunity to brush up on my basic geometry. :hmm3grin2orange:

You can't be exact, but if the 80% point comes in at .70, I'll round it down and use a pipe with 5/8" diameter (.625) ID rather than going up to a 3/4" (.750).
I may lose an imperceptible amount of power, but it better than going too far.


----------



## JONSEREDFAN6069

some pics of the new 670 mod.












have a bit of grinding and blending left to do. then paint.


----------



## rngrchad

JONSEREDFAN6069 said:


> some pics of the new 670 mod.
> 
> Oh my! My eardrums hurt just looking at that Jonsered. Gnarly muff mod man. I'll be she sounds like a 2stroke motocross bike!


----------



## JONSEREDFAN6069

ya she's loud and pulls like a fr8 trane too. thanx


----------



## ironman_gq

K9-Handler said:


> Always. It's given me an opportunity to brush up on my basic geometry. :hmm3grin2orange:
> 
> You can't be exact, but if the 80% point comes in at .70, I'll round it down and use a pipe with 5/8" diameter (.625) ID rather than going up to a 3/4" (.750).
> I may lose an imperceptible amount of power, but it better than going too far.



according to my math 5/8 pipe will have a free area of .31 sq. in. if ID of the tube is .625 3/4 will be .442 sq in if ID is .750 so you would need two 5/8 pipes to get around 80% of the .70 port area which is .56


----------



## K9-Handler

ironman_gq said:


> according to my math 5/8 pipe will have a free area of .31 sq. in. if ID of the tube is .625 3/4 will be .442 sq in if ID is .750 so you would need two 5/8 pipes to get around 80% of the .70 port area which is .56



Congratulations! You get a gold star for math! 

But you missed my point.

I should have been clearer. When all your math is done, you decide your theoretical saw needs a pipe with a .70 ID to do your 80% job (big saw). Since no stock, off-the-shelf pipe has an ID of .70, then I would go with the .625 rather than the .750 pipe.

All I was advocating is to err on the low side rather than the high side. 

The MS280 I just muffler-modded had all 54.7 ccs of displacement exhausting through a single .325 hole in the muffler! I'm surprised it didn't whistle!  Even opening the hole to 50% of the exhaust port would have made a huge improvement. For a work saw you can achieve great gains without bumping up against the high-side ceiling.


----------



## mickeyd

I cut a small rectangular hole in the muffler of my new MS290 and opened up the final exit just a little .I can hear and feel a slight difference. I am afraid to go any more till Im sure of how to tune the carb. the H is already at the stop. I have searched the site with out finding any details on how to remove the stops .can someone post some pics and a step by step instructions on how to do this 
thanks Mick


----------



## Metals406

mickeyd said:


> I cut a small rectangular hole in the muffler of my new MS290 and opened up the final exit just a little .I can hear and feel a slight difference. I am afraid to go any more till Im sure of how to tune the carb. the H is already at the stop. I have searched the site with out finding any details on how to remove the stops .can someone post some pics and a step by step instructions on how to do this
> thanks Mick



Mick, others here do it differently than myself... But heating a small nail or screw (or anything small and metal), and melting the tabs off works pretty good. Take your time, and nothing will get melted that shouldn't be.

Like I said, others do it different.


----------



## (WLL)

mickeyd said:


> I cut a small rectangular hole in the muffler of my new MS290 and opened up the final exit just a little .I can hear and feel a slight difference. I am afraid to go any more till Im sure of how to tune the carb. the H is already at the stop. I have searched the site with out finding any details on how to remove the stops .can someone post some pics and a step by step instructions on how to do this
> thanks Mick


i like to use a sheet rock screw, thread it in , yank e'm out. works like a charm


----------



## BrocLuno

*In case anyone is interested?*

New (TTI) Homelite UT10520c (pre "tooth-less" adjuster) has catalytic muffler. But, very easy to mod. Internal diffuser is wide open on bottom side (facing cat mass). Only restriction is the outlet hole. 

Remove the muffler, remove the discharge cover and screen, drill second 5/16 ths hole above the existing one. File the bridge away between the holes and viola, you are at about 75% of exhaust port area. Reinstall screen and final discharge cover and you are ready to run. Looks stock, louder and stronger.

Use Double D carb tool to reset the jets and this thing will actually pull the 20" Carlton chain. Takes about 8 hours running time for the motor to break-in using personal blend of EGD / FC oils (1/2 full synthetic, 1/2 low ash dino oil - both EGD) at 32:1. Once broken in, it makes OK power. Not a 60cc motor, but WAY better than stock


----------



## harrygrey382

ssiimmss said:


> does anyone take the time to measure the exhaust port and do the math or are ya'll just eye ballin it an making sure that your below the 100% mark?


yeah - I've been reading this thread, and searching, and haven't found a nice solution to finding the area of the exhaust port at the cylinder wall. Some put paper in and trace it - ok so it flattens out (apparently no biggy), but how do you do it then. In my conversion from 038FB to 038M I'm modding the super muffler onto the magnum. A trace will leave me with a vaguely eliptical area. How do I proceed now - scissors? major/minor diameters and a formula? How do people normally measure the exhaust port? It's something rarely covered and that's annoying because it's the first step...


----------



## Urbicide

There was some discussion a while back about a very high tech way of measuring the area of the port using uncooked spaghetti. You insert as much of the uncooked spaghetti rods into the port (like pencils in a pencil holder) as you can. Then you pull them all out and count them. The number of spaghetti rods would = 100% of the actual port area. Now if you are using say 85% as your desired muffler exhaust opening, you would subtract 15% of the spaghetti rods from your bundle. The remaining rods would be equivalent to the desired area of the exhaust opening. This is explained a lot better if you can find the original posts describing it. For some reason I now am hungry.


----------



## K9-Handler

harrygrey382 said:


> yeah - I've been reading this thread, and searching, and haven't found a nice solution to finding the area of the exhaust port at the cylinder wall. Some put paper in and trace it - ok so it flattens out (apparently no biggy), but how do you do it then. In my conversion from 038FB to 038M I'm modding the super muffler onto the magnum. A trace will leave me with a vaguely eliptical area. How do I proceed now - scissors? major/minor diameters and a formula? How do people normally measure the exhaust port? It's something rarely covered and that's annoying because it's the first step...



I have done both. On the rectangular ports I use the inside measuring probes on a digital caliper (if I can reach the port). If I can't reach it directly I use dividers and set them to the inside edges of the port's length and width, then measure the dividers with the caliper. It's not like we're doing precision machining work, here -- approximation is good enough. Plus or minus .015" is OK.
For elliptical ports I measure them using the same method, then plug the dimensions into the formula for finding the area of an ellipse. Yes, I have to look up the formula every time! 
It's the minor diameter /2 (short radius) X the major diameter /2 (long radius) X Pi (3.14) .
Once you've done a couple, it is a really quick "first step."


----------



## gremlin

Not to cut anyone down. Im no chainsaw guru by any means. I use a 5/8 pipe on all my muffler mods where room and saw frame allows. Iv had no issues thus far. I run my saws pretty hard too. Wicked loud for sure but tons of power


----------



## JJay03

Lakeside sent you a PM.


----------



## flashy

Haywire Haywood said:


> Thin dremel tool cutoff wheel and a screwdriver to lift the slots open...
> 
> Ian



Would it be a bad idea to cut the slits horizontally or at a 45 deg. angle to try and prevent debris from getting in the muffler?


----------



## stone69er

Any one ever modded a Husky 450e x-torq??Or a Husky 61,been going to mod the 61 but after reading all these post Im getting a bit frenzied


----------



## loghog

*spark arrestor*

where can you get the spark arrestor screen, what is it made of.i have some fine ss steel screen that might work?


----------



## BrocLuno

SS screen should work if it's not too fine. If it is it may get too hot (small wire) and burn through. All my saws use a pretty course screen. 

You can also use an internal screen from Poulan Parts or your local Poulan shop from any older saw like a 2250 (with 2 piece muffler). It fits over the diffuser and is available for a dollar or two. You can cut it down to square pieces needed for other muffler styles. This screen does not burn through. It has a sort of goldish cast, so I assume it's an alloy designed to take high temps? Anyway, because it's a loop, there's more than enough for two or three saws that use flat inserts under the final outlet.


----------



## Metals406

I ordered screen from McMaster-Carr... 1 sq. ft. was around $24.00 shipped. The screen has a .030" opening, and .020 wire size... It was woven screen. I noticed a Bailey's muffler screen had an opening of approx. .020".


----------



## SLlandscape

*MS 310 mod*

Thinking about modding my 310 but I can't make myself do it. To concerned that I might screw it up. I'm thinking about using the cover for the arrestor screen for the location of the hole. going to start with a 7/16" hole and see what happens. Any suggestions as to where I should place the hole, or will this work. 

Thanks


----------



## BrocLuno

*Maybe, picture would help?*

Depending on what the size of the opening is under the screen, that might work. I open the hole under the screen to whatever is the best fit and biggest that will work. Then mod the screen cover so it will flow more. Sometimes that just means bending the louvers or bump-out so it offers more cross section?


----------



## Metals406

Here's a new (from Bailey's) 064 muffler I did for Brad Snelling. I removed the cage from inside, welded the factory opening closed, and removed the factory deflector... I welded the new port on, and added stainless screen.


----------



## deer slayer

Looks good, nice work!!!


----------



## Metals406

deer slayer said:


> Looks good, nice work!!!



Thanks.


----------



## SLlandscape

BrpcLuno said:


> Depending on what the size of the opening is under the screen, that might work. I open the hole under the screen to whatever is the best fit and biggest that will work. Then mod the screen cover so it will flow more. Sometimes that just means bending the louvers or bump-out so it offers more cross section?



One of my concerns is that there is a hole that goes from the port at the block straight to the cover of the muffler with no obstructions. The hole under the screen cover is about 3/4" in size. Been really busy with work and the fire dept, but I'll post pics of the muffler as soon as I can to give you a better idea of what I'm dealing with, and to provide better info.


----------



## billyjoejr

*Timberwolf 026 Muffler Mod thread*

Not sure if mentioned in this thread but I thought it should be. 



Bowtie said:


> Timberwolf posted up some charts on muffler mod gains per size on an 026 I believe. There is a lot of info there. Have to do a search to find it, I cant remember the thread title.




Here it is


http://arboristsite.com/showthread.php?t=44816


----------



## billyjoejr

*Timberwolf 026 Muffler Mod thread*

Not sure if mentioned in this thread but I thought it should be. 



Bowtie said:


> Timberwolf posted up some charts on muffler mod gains per size on an 026 I believe. There is a lot of info there. Have to do a search to find it, I cant remember the thread title.




Here it is


http://arboristsite.com/showthread.php?t=44816


----------



## Haywire Haywood

Maybe it's in the other thread, I'll have to look, but it would be nice if those muffler opening numbers were converted to percentage of exhaust port area at cylinder including the stock opening.

Ian


----------



## wildwood

372xp first mod i did on one of my work saws.


----------



## woodyman

Heres a muffler mod I did on my 1980 Husky 44.I welded up a small hole I drilled in the front and cut out a round hole where the stock was and gutted the muffler and welded a 5/8 straight pipe on.


----------



## wildwood

here r a couple of vids of 2 of my work modded 372s
the shorter vid has a bigger muffler outlet and a big bore, the longer vid is standard cylinder i ported and played with the piston skirt and a 19mm muffler outlet
http://www.youtube.com/watch?v=f60JQVitBRs

http://www.youtube.com/watch?v=PZ49rHiY2zU


----------



## JONSEREDFAN6069

Nice wildwood, is all that wood your's? Man i'm jealous!!!


----------



## treebreeginning

Four Paws said:


> Well, maybe the moderators can sticky this thread, or something - I hope it can grow into a good bit of information, sort of like a reference guide, that folks can use to find info on modding their mufflers, rather than seeing a new post in the forum every other day.
> 
> *YOU NEED TO MOD YOUR MUFFLER!​*See this--> http://www.palmtreeservices.com.au/video/33cchomelite.wmv
> 
> A basic muffler mod "opens up" the exhaust system to allow more gasses to flow out of the engine with less restriction. This is accomplished with a bigger 'hole' in the muffler.
> 
> SO, What do you need to mod your muffler? A little time, a little patience, a few tools, and a little skill.
> 
> You will need the following tools:
> 
> Drill and drill bits - up to 1/2" for most smaller saws, up to 3/4" for bigger saws.
> 
> A welder (MIG/TIG) or a set of Oxy/Act torches and proper filler material - yours or access to your friends, it doesn't matter, but you shouldn't be trying to JB weld your muffler together!
> 
> Dremel tool/files/die grinder - Just something to clean up the burrs on your steel pieces.
> 
> Hacksaw and tin snips - depending on the style of mod you plan to do, these will come in handy and at times, be necessary.
> 
> An assortment of steel - 1/2" - 3/4" tube, 18 ga. sheet, spark arrestor screen.
> 
> Mods are accomplished MANY different ways. But, the most basic modification is to drill a hole in your muffler. This increases the area your exhaust has to exit the muffler - allowing the saw to breathe better, run cooler, and perform better. Holes should be drilled in a convenient location where the exhaust won't blow back at the saw operator, burn plastic pieces on the saw, start a forest fire, etc. "Measure twice, cut once" and make sure you know what you want before you start hacking away at your muffler. The surface area of the new exhaust hole should be about 80 - 85% of the exhaust port surface area at the cylinder. Taking your muffler too far, and making too big an exhaust hole will actually decrease your saws performance!
> 
> Some saws have a 2 piece muffler. These can be disassembled and the baffles inside can be modified or removed. Some Stihl saws can also be equipped with a factory dual port muffler cover which usually makes any additional muffler mods unecessary for most folks. Saws without a 2 piece muffler cover can be cut open and gutted - however this is rather involved and requires more skill to put them back together (best accomplished with a TIG welder).
> 
> After you have your holes drilled and baffles modified, you need to "finish" your muffler. Finishing it can be accomplished many ways - the "looks" of the mod should be pleasing to you, but the bottom line is, the muffler MUST function well to give the desired performance. ALWAYS install a spark arrestor screen over the new hole you have drilled in your muffler! Based on how far you have taken your muffler, it's initial design, and your patience/craftsmanship skills, will determine how you finish it. I have included some picture of muffler mods below.
> 
> Some folks drill a hole, and use a washer with a screen behind it, welded to the muffler to "finish" it as seen below on rahtreelimbs Husky 359.
> 
> 
> 
> 
> 
> 
> On a muffler mod I did to my Shidaiwa 577, I removed the factory deflector, and fabricated a new one out of 18ga sheetmetal, and 1/2" tube. My new piece replaces the factory deflector, is bolted to the muffler, and has a spark arrestor screen behind it. The internal baffles in the factory muffler were very free flowing, and I did not have to modify them.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> I encourage others to add pertinent information and pictures to this thread with descriptions of their work, what saw it was on, etc. Please do not use this thread for chit-chat.



can i mod a 338xpt


----------



## JONSEREDFAN6069

mod on my 372xpg with the xpw top end and ported. also opened up the stock opening a little too.


----------



## Metals406

JONSEREDFAN6069 said:


> mod on my 372xpg with the xpw top end and ported. also opened up the stock opening a little too.



Is that the new Husky you just got?


----------



## JONSEREDFAN6069

yup, found out it has an xpw top end a pop up piston and ported, it's a beast.


----------



## Metals406

JONSEREDFAN6069 said:


> yup, found out it has an xpw top end a pop up piston and ported, it's a beast.



LOL What!? This is the same one you traded for? And it had all that work done to it?.. And you didn't know it?? LOL

THAT'S AWESOME!


----------



## JONSEREDFAN6069

Metals406 said:


> LOL What!? This is the same one you traded for? And it had all that work done to it?.. And you didn't know it?? LOL
> 
> THAT'S AWESOME!



thats the one i paid $325 for i traded the 670 for a 630 a 920 that little one in the chainsaw pics and another jonsered parts saw and 3 husky parts saw's and he also gave me $200.00


----------



## Metals406

JONSEREDFAN6069 said:


> thats the one i paid $325 for i traded the 670 for a 630 a 920 that little one in the chainsaw pics and another jonsered parts saw and 3 husky parts saw's and he also gave me $200.00



Your new nickname is Sir Wheeler McDealer.


----------



## JONSEREDFAN6069

Metals406 said:


> Your new nickname is Sir Wheeler McDealer.



lol thats kewl, how do i put that as a quote in my signature?


----------



## Metals406

JONSEREDFAN6069 said:


> lol thats kewl, how do i put that as a quote in my signature?



[qu0te] Words here [/qu0te] Zero's replaced O's so it doesn't turn into a quote.


> Words here



Just like above. Make sure you make QUOTE all in upper case.


----------



## JONSEREDFAN6069

lol i'll try later. i cant figure it out now.


----------



## treebreeginning

*338xpt*

anyone ever mod ur 338xpt was wondering if u can get more power out of it


----------



## BobL

*880 muffler mod*

Because things get lost pretty quickly in the regular threads I though I would post a link to my 880 muff mod here as well.


----------



## JONSEREDFAN6069

BobL said:


> Because things get lost pretty quickly in the regular threads I though I would post a link to my 880 muff mod here as well.



wow Bob that thing's sik. chrome always looks good. must be pretty easy on the ears too.


----------



## CHEVYTOWN13

JONSEREDFAN6069 said:


> wow Bob that thing's sik.



You said it tocayo!


----------



## BobL

JONSEREDFAN6069 said:


> wow Bob that thing's sik. chrome always looks good. must be pretty easy on the ears too.



It's actually just ally pipe, it comes up really nice on the buff. It will discolour with heat but it can always be polished up again.


----------



## Metals406

BobL said:


> Because things get lost pretty quickly in the regular threads I though I would post a link to my 880 muff mod here as well.



That looks sweet!


----------



## BobL

Here it is with the regular clutch cover on. The muff mod was never designed to cope with the regular cover but it goes on just fine and doesn't look too bad either. The chain brake touches the pipe but works fine


----------



## hh1341

*Meg*

I'm having fun with this one.......


View attachment 94699


----------



## 820wards

*820 PowerBee*



hh1341 said:


> I'm having fun with this one.......
> 
> 
> View attachment 94699



Does anyone have any muffler mods for an 820 Powerbee motor. I need to build a muffler for the mill I'm building and need now only to build the muffler.

TIA
jerry-


----------



## gonecountry

BobL said:


> Here it is with the regular clutch cover on. The muff mod was never designed to cope with the regular cover but it goes on just fine and doesn't look too bad either. The chain brake touches the pipe but works fine



So BobL is ther any video of your saw running so we can hear that pipe. If it has been posted before I havent found it. If it hasnt you should make one:greenchainsaw:


----------



## knockbill

*muffler mod on small poulan*

heres an easy mod on a small poulan saw,,,
1st, drill out the baffle holes, i added an extra one at the bottom,, next, i closed up teh small original slit it the muffler case, it came out the back, and got oil all over teh saw,,then assemble teh screen, and baffle back in the case,,, finally, i cut out the front case, and migged in an outlet pipe,,,
still need to re-assemble the saw, adjust the carb and cut some wood...........


----------



## BobL

gonecountry said:


> So BobL is ther any video of your saw running so we can hear that pipe. If it has been posted before I havent found it. If it hasnt you should make one:greenchainsaw:



Sorry but my DSLR has no video recording capability and my phone camera is kaput. I will see if BIL can come around with his camera to the milling yard and record the saw. With the 14 mm opening insert it sounds more like a very loud scooter than a chainsaw. I have installed the 15 mm opening but can't run the saw at home or the neighbors will go spare. I have 16, 17 and 18 mm inserts plus of course no insert , or fully open at 19 mm, that I will eventually try out. The reason I have done this is because this is purely a milling saw and I want to stay in tuning range of the main jet without going too lean. This is just a hobby for me so I am in no rush to do this, fortunately I'm fairly patient so this could take me a while to sort out.


----------



## gonecountry

BobL Thats alright, just curious as to how it sounds. When ever you get a chance to record some vid lets hear it. I bet it sounds good, different good


----------



## hh1341

*My mod*

This is an old thread, but it might be helpful.

I explain the math I used to arrive at my sizes.

http://www.arboristsite.com/showthread.php?t=90616

Carl


----------



## BobL

hh1341 said:


> This is an old thread, but it might be helpful.
> I explain the math I used to arrive at my sizes.
> http://www.arboristsite.com/showthread.php?t=90616
> Carl



Thanks Carl but I have no probs working out the relative area increases. What I don't want to do is open the pipe up so much that the saw runs too lean. The inserts allow me to open up the pipe in a controlled way to make sure I stay within the tuning range of the main jet. I don't want to increase the jet size to enable me to run at fully open (ie 19 mm) as this sucker is a milling saw and already uses enough juice as it is.


----------



## hh1341

*Inserts*



BobL said:


> Thanks Carl but I have no probs working out the relative area increases. What I don't want to do is open the pipe up so much that the saw runs too lean. The inserts allow me to open up the pipe in a controlled way to make sure I stay within the tuning range of the main jet. I don't want to increase the jet size to enable me to run at fully open (ie 19 mm) as this sucker is a milling saw and already uses enough juice as it is.



Bob, I went with inserts too.

I found it worked best at 19mm, then I put a stubby 8 degree megaphone on it, just for laughs, and it even worked better. Ton more power.

Carl


----------



## Motodeficient

Country1 said:


> Not much has been said about this mod?? I assume it's not as good as Lakeside's??? I would be a lot simpler to do... No screen, but the "slits" wouldn't be that prone to letting in debris. Has no one else done this?



How much louder was it with slits in the side of the muffler? I might go this route on my 361


----------



## SLlandscape

SLlandscape said:


> Thinking about modding my 310 but I can't make myself do it. To concerned that I might screw it up. I'm thinking about using the cover for the arrestor screen for the location of the hole. going to start with a 7/16" hole and see what happens. Any suggestions as to where I should place the hole, or will this work.
> 
> Thanks



okay, now that I have some free time (at least until the next page out) here are a few pictures of the muffler on my ms 310 that I want to mod. I'm looking for any suggestions on what size of hole to make and where I should put it. the 2nd pic is with the cover and spark arrestor removed. Thanks in advance.

A side note: directly above the 2 slots is a hole, above the baffle, that goes straight to the block with no obstructions. this is where I am considering the placement of my port. I hope I am not confusing any one in that description.


----------



## ironman_gq

on mine I connected the two outlet holes in the muffler and made a slot 3/8" wide between them then I cut out the bottom of the deflector so looking at it straight on you cant tell I did anything but if you look from the bottom you can see how its opened up. Made quite a difference in the saw.


----------



## Bowtie

I have about 2 tanks through the new 361. Couple more, and Im gonna Lakerize it. Best muffler mod yet in my opinion. It works awesome, and looks classy! Plus, its easy to do.


----------



## Stihlman441

rahtreelimbs said:


> Even a saw as new as the Stihl 441 can be easily muffler modded!!!



How much differance has this mod made to your 441

Cheers


----------



## Smokeeater514

*MS 180c*

Would there be any reason to do a mod on my MS 180c (if so what is recommended) that I just picked up for $20?. Im rebuilding it for something to do.


----------



## ironman_gq

absoulutely. you need to put a different carb on it though cause the stock one isnt adjustable. look here for the carb mod http://www.arboristsite.com/showthread.php?t=98067&highlight=adjustable+carb
Its really easy to do and well worth it.


----------



## JJay03

Still havnt done mine yet but I love using the saw even stock.


----------



## SawTroll

JJay03 said:


> Still havnt done mine yet but I love using the saw even stock.



So do I - but I will put the "Andy muffler" on it this year.......


----------



## billyjoejr

SawTroll said:


> So do I - but I will put the "Andy muffler" on it this year.......



So that is where Andy disappeared to. 
Is he on his way to your place to finally get that muffler on your saw, so that the rest of us can finaly get an experts unbiased fact based opinion of the Mod?


----------



## SawTroll

billyjoejr said:


> So that is where Andy disappeared to.
> Is he on his way to your place to finally get that muffler on your saw, so that the rest of us can finaly get an experts unbiased fact based opinion of the Mod?




:biggrinbounce2:



opcorn:opcorn:


----------



## Trigger-Time

Country1 said:


> Not much has been said about this mod?? I assume it's not as good as Lakeside's??? I would be a lot simpler to do... No screen, but the "slits" wouldn't be that prone to letting in debris. Has no one else done this?




http://arboristsite.com/showthread.php?t=49342&highlight=hillbilly


http://arboristsite.com/showthread.php?t=60417&highlight=hillbilly


----------



## SawTroll

SawTroll said:


> So do I - but I will put the "Andy muffler" on it this year.......



I finally got around to it last saturday.

After a good warm-up session, before and after cuts were made in 11 and 14" birch, and my counting (no stop-watch or video) indicate a 10-15 percent speed gain. 

The cuts were made with a 15" bar, 36RSC, 8-pin rim, at 14500rpm WOT settings.

I experiensed little or no sound gain - which is a bit surpricing.....


----------



## Tzed250

ST has a Hotsaw!!!


----------



## Mo Wood

*muffler mod*

can i pay somebody to do this to my poulan 4000 thanks contact me at [email protected]


----------



## billyjoejr

We need a volunteer to send SawTroll an unmodified American muffler so he can experience a choked up saw. :hmm3grin2orange:


Since you experienced no gain in sound, I assume that the modified American muffler was opened up to be about the same as an unmodified European Muffler.


But since you experience a gain in cutting speed, 
this is a sure sign that you are going *DEAF* :monkey:


----------



## SawTroll

billyjoejr said:


> We need a volunteer to send SawTroll an unmodified American muffler so he can experience a choked up saw. :hmm3grin2orange:
> 
> 
> Since you experienced no gain in sound, I assume that the modified American muffler was opened up to be about the same as an unmodified European Muffler.
> 
> 
> But since you experience a gain in cutting speed,
> this is a sure sign that you are going *DEAF* :monkey:



You are right that my 361 is a German made Euro one, and was not as choked up as the stock US ones. The cylinder has a different part number, as well as the muffler.

It ran pretty "entusiastic" as it was, but there still was a gain......:rockn::rockn:


----------



## asthesun

i have a question about modding my ms 250. i recently retired my old one, so its a parts saw. i'm planning on modding the muffler a bit from the old one and swapping it out on the new one, so if i mess up, i can fall back on the factory muffler. this is my plan, i'm half done already. i dont have pics yet so bare with me while i try to describe it. i started by removing the bracket on the front, it has three vents that angle towards the bar. i took a scrench and made all 3 about twice or 3 times as wide. on the inside of the factory baffle, there's only a staggered grid of about 15 holes on the topside of it. muffler is crimped together and i didnt want to mess with that, instead i've drilled 10 additional holes, 5 on each of 2 sides of the baffle, by going through the side of the muffler. (yes there's holes in the muffler now) i plan on tacking the holes shut when i'm done. the holes are roughly the same size as the ones from the factory. the hole behind the bracket with the vents is about 1/2 inch or so, i'll drill that out some more and i'll be done. also putting the spark arrester screen back and blowing the bits of metal out of it.

any problems with what i'm doing so far? or something else i need to do also?


----------



## asthesun

asthesun said:


> i have a question about modding my ms 250. i recently retired my old one, so its a parts saw. i'm planning on modding the muffler a bit from the old one and swapping it out on the new one, so if i mess up, i can fall back on the factory muffler. this is my plan, i'm half done already. i dont have pics yet so bare with me while i try to describe it. i started by removing the bracket on the front, it has three vents that angle towards the bar. i took a scrench and made all 3 about twice or 3 times as wide. on the inside of the factory baffle, there's only a staggered grid of about 15 holes on the topside of it. muffler is crimped together and i didnt want to mess with that, instead i've drilled 10 additional holes, 5 on each of 2 sides of the baffle, by going through the side of the muffler. (yes there's holes in the muffler now) i plan on tacking the holes shut when i'm done. the holes are roughly the same size as the ones from the factory. the hole behind the bracket with the vents is about 1/2 inch or so, i'll drill that out some more and i'll be done. also putting the spark arrester screen back and blowing the bits of metal out of it.
> 
> any problems with what i'm doing so far? or something else i need to do also?



reposting since noone's answering in other post


----------



## kc2strokerider

*husky 455*

does anyone have pics of a muffeler mod on a rancher 455


----------



## hotshot770

*muffler mod on a 028wb*

I have a 028 wood boss.I want to try a muffler mod. Would it be worth my wile to mod the muffler on this size saw? If so, just exactly what would I have to do.What size holes would it take? First time on this site,glad to be here! Thanks


----------



## TravisL

okay, I didnt want to start another thead on modding a 361, but anyway. without touching the stock port, how big of a hole should be made in to 361 for max gain?


----------



## wheelman

I just finished modding a 028 wood boss. I ported it ,took out the base gasket ,and modded the muffler. Its hard to tell how much I gained with the muffler mod since I did all of this at one time. These mufflers are easy to mod just take the front cover off and if you look inside you will see that there is a lot of space post spark arrestor. All I did was drill in from the outside through 4 of the holes in the heat shield that will end up in the same cavity as the stock exit port.


----------



## canopyboy

So tonight I did it. MS260 muffler mod, including new 194 carb. That was easy. Including re-soldering the wire for the kill switch I broke doing the carb and tuning the thing at least a bit, it took about an hour. Sounds great, should have done this a long time ago. Can't wait to try it in a piece of oak tomorrow.

I calculated 80% of my exhaust port area at 0.40 in^2. Used an end mill in a drill press to enlarge the existing port (maybe 5/16 dia max = .077 in^2). Also opened up the baffle on the other side of the screen a bit, although it wasn't as bad. Screen still fits and seals. Piece of cake.

Hoping someone at the GTG this weekend in WV can check my tuning though. Think I'm getting better, but would like to calibrate against a tach or a more experienced ear.

Sorry for the cellphone quality pics....


----------



## SawTroll

TravisL said:


> okay, I didnt want to start another thead on modding a 361, but anyway. without touching the stock port, how big of a hole should be made in to 361 for max gain?




I believe the tubes Andy prefere is 16mm on the outside.


----------



## K5krawler

canopyboy said:


> So tonight I did it. MS260 muffler mod, including new 194 carb. That was easy. Including re-soldering the wire for the kill switch I broke doing the carb and tuning the thing at least a bit, it took about an hour. Sounds great, should have done this a long time ago. Can't wait to try it in a piece of oak tomorrow.
> 
> I calculated 80% of my exhaust port area at 0.40 in^2. Used an end mill in a drill press to enlarge the existing port (maybe 5/16 dia max = .077 in^2). Also opened up the baffle on the other side of the screen a bit, although it wasn't as bad. Screen still fits and seals. Piece of cake.
> 
> Hoping someone at the GTG this weekend in WV can check my tuning though. Think I'm getting better, but would like to calibrate against a tach or a more experienced ear.



This saw flat out RIPS. I really was surprised how well this saw runs! I think I need to go find an 026 or 260 and do the same. Now I am surprised there isn't a blueprint that you've drawn up in your spare time to act as an aid for others!


----------



## hotshot770

*wheelman base gasket*

Wheelman what is the reason for removing the base gasket and do you use any sealant on it?


----------



## canopyboy

K5krawler said:


> This saw flat out RIPS. I really was surprised how well this saw runs! I think I need to go find an 026 or 260 and do the same. Now I am surprised there isn't a blueprint that you've drawn up in your spare time to act as an aid for others!



Thanks, glad you liked it. I'm pretty happy with the results, although now I want to try someone's ported 260 to compare.

Ummm, as for blueprint that opening is made with a half inch endmill, so 1/2" wide by 1" long. A second 1/2" hole is put through the first baffle. Other than that a new 194 carb and used Ryan's tach to set WOT at about 13,500. The rest is stock.


----------



## ridgerunner97

I ran that saw at the gtg also and would have to agree it was pretty darn impressive. I have ran an old 026 at work that me and the mechanic did a lil muff mod on and i can say that your ms260 runs way better than an 026. If i were you chris the hell with the 026 and snag an ms260 and thats coming from a husky fan lol.


----------



## spiffy1

I'll second SawTroll. Earlier in this thread you'll see he tried the 14mm then a 16 mm; I don't recall that he noted a performance difference, but he left it at 16. 

I just finished mine today!  Thanks Andy; no matter where you're hiding these days! 

Using the 16mm screen/clamp part numbers in this thread [it seems somebody here has it in their sig line too], you can get a pretty nice fit with a 5/8 X 1/2 spacer tube [roughly .050 wall - the math would be 16th but they leave about 64th each way for clearance]. I do like the look of the 16mm; the Ace Hardware tubes had an ID taper at the ends so a little grinding on the OD to make the end a full half round - the screen went down flush without even a hammer.

The brazing litterally was minutes. I had to put my own twist on it, so I brazed it before drilling and used the tube as a drill guide rather than dremeling a round hole oval. Doubt I saved any time [with an endmill instead of drill though!] over the dremmel oval as grabby as drill bits are, but it was fun to try!

The one part that got me scratching my head, was that I had it in my head I could pull the limitters without removing the screw cowling [and now somebody is going to tell me it can be done], but gave up, removed the intake and the cowling [at this point wishing I'd blown off the saw better] a drywall screw turned a little further after it it hit the lean end, back to rich, and it came right out. I ground off the tab and replaced it, but now wonder if I could have just turned it 180 richer?


----------



## spiffy1

Paint is drying!!! Then fixed up with the screen and back on the saw.

Did anyone else notice this exit seems to get as much or more volume as the factory? Maybe just the better angle for my non-scientific handtest! I didn't notice a particular increase in noise either - maybe a bit deeper but not louder.


----------



## spiffy1

Uber-Scientific test equipment! The torque-test on the left gave me the best feel at 1/4richer over original [right at limit]: for both before and after. Is that strange?

The power test (picture doesn't show it well, but bar [25"; RSC freshly ground, fairly agressive rakers] has a little length until the middle then just barely exits until the very bottom) was a half dry stump, hackberry perhaps?, monitored with the "nano-second chronograph" on the right. The high end torque was nice, but my first attempt after the mod was 24 seconds just like the first test [original muff, 1/4turn rich]. Both times I stalled right before the bottom, and I fuddled getting back to RPMs worse on the "after" run. However, if operator efficieny could be considered to be offset by the growing diameter [about 1/2" per cut], I did probaby gain 10-20% as I got it down to 20 by the 4th or so, with a light touch and really backing off at the bottom.

That seem about right? 

Anyone know if I should get a new limitter cap, or since the old one went on fine, assume the setting won't wander around?


----------



## spiffy1

The picture labeled "nobar" is more "look Ma no hands" it's there, just can't see it being right at the end.

I didn't tach it [I realized I can only get to 10K 4cycle], but it dogged at 1/4turn more and high revved at about 1/2 less; that seems I could run a bit leaner and more rev, but I liked the torque test there - that seem about right? As someone [THALL perhaps] noted the 4cyle is a bit hard to hear even muff modded.

Also, I had to play with the idle [didn't even grind the limit on that one though] a bit before the muffmod, but think I took it right back to original after, did have to bring down the idle speed though to stop the chain after the muffmod. Maybe a just a bit faster idle now than stock, but as soon as I got the chain to stop consitantly, I was happy.


----------



## spiffy1

Make the images a bit more visable:


----------



## wheelman

hotshot770 said:


> Wheelman what is the reason for removing the base gasket and do you use any sealant on it?



I took out the base gasket to reduce the squish. Yes I used ultra copper sealant and a .004 shim to get the squish right.


----------



## leiterch

*some mod assistance*

any northern michigan guys that could give some assistance with a muffler mod or a couple. I would like to mod the poulan and then maybe the 372. wouldn't mind a little over sight and help with tuning, also welding/brazin not my specialty.

thanks.


----------



## TraditionalTool

*Requesting pics for 359 mod, going out sides, not front*

I'm looking to mod the muffler on a 359 I just got recently.

Anyone have any pics of a mod that has the pipes or gills on the side(s)?

I've seen a few that have opened the front, with either pipes and/or washer/screen, but want to stay away from the front due to the type of cutting I'll do with the saw. The muffler will be butted up against the tree while I'm cutting. I'm trying to avoid the excessive heat to my hand which is holding the bar.

Regards,
TT


----------



## southbound

Time for my dumb ???

I am modding a MS290. I have drilled all the holes I am comfortable with for now..I have opened up the front shield and removed the limiter caps...

My question has to do with the limiter caps..Is it better to....

A. tune saw then reinstall the caps

B. trim off the tab reinstall the limiter caps then tune...

My main concern is if I trim off the tabs the screws may turn while I run the saw.. I betting this is not the case but I want to make sure..

Thanks in advance.....


Found the answer....



"Get A drywall screw, pull both limiter caps cut tabs ,put limiter caps back in. Then adjust, start 1 full turn out on both after each adjustment readjust (LA) idle screw. Should be about 13500-14000 RPM's. I leave mine a little in the "ROUGH" (RICH) just to be cautious. Hope this helped"


----------



## splitpost

*660 pics*

just some pics of my 660 muf in stock form is there a need to mod this?


----------



## 1967smithe

splitpost said:


> just some pics of my 660 muf in stock form is there a need to mod this?



If you want faster cuts...It looks a bit restricted in the back half. You can cut out the baffle box and open the hole on the side.


----------



## wheelman

The exit port on the 660 mufflers is very restrictive. Get a die grinder and open up the factory exit at the very least. If you can afford to get a dual port front cover and let your saw breath.


----------



## BarkBuster20

i was reading some people like to lean the saw up a bit with a MM and some do opposite. so if you MM a saw and richen it up, it will cut faster than a stock muffler tuned correctly? might be a dumb question but im just trying to learn. thanks


----------



## southbound

BarkBuster20 said:


> i was reading some people like to lean the saw up a bit with a MM and some do opposite. so if you MM a saw and richen it up, it will cut faster than a stock muffler tuned correctly? might be a dumb question but im just trying to learn. thanks



If you drill the holes it will lean out the saw. You will have to reset the carb to richen things back up......

Yes drilling the holes and resetting the carb made my saw cut faster...


----------



## BarkBuster20

southbound said:


> If you drill the holes it will lean out the saw. You will have to reset the carb to richen things back up......
> 
> Yes drilling the holes and resetting the carb made my saw cut faster...



alright i was confused i thought the saw itself would actually be running leaner. my buddy has his 460 pushing 16k rpm


----------



## lectrocrew

BarkBuster20 said:


> alright i was confused i thought the saw itself would actually be running leaner. my buddy has his 460 pushing 16k rpm


The richer fuel mixture means it also gets a bit more lubricant. Also a lean mixture burns too hot and will eventually trash the piston (and probably more).
A lean saw will run faster free turning RPM but it lacks torque when put into the wood.


----------



## bigjeepmudder

*Modded J 621*

Did my first muffler mod lastnite. I ground off the lip around the factory hole, then drilled in through the baffle with two 3/8 holes then drilled two smaller holes next two the factory hole and then mig welded a 1" square tube cut at an angle out the front. I would have gotten more in depth with it but i'm learning, addicted now tho. I had to tune the carb just a bit but it is snappier in the throttle and gained a louded voice.


----------



## lectrocrew

bigjeepmudder said:


> addicted now tho.


It happens. Welcome aboard!


----------



## Dr. Hackemoff

splitpost said:


> just some pics of my 660 muf in stock form is there a need to mod this?



I finally modded mine and I wish I had done it sooner. But I didn't want to make the saw significantly louder.

So I simply drilled one extra hole in the box and in the cover (see the pic). The extra hole in the box increased the area by about 20%. The extra hole in the cover increased the area by 38%, which isn't insignificant. While I took my time doing it, this could probably be done in ten minutes (don't forget to wirebrush the screen while you're there).

The first thing I realized when I restarted the saw was that the chain was running in idle. Aha, something is happier. I also found with this "minor mod" that the saw noise didn't increase significantly AND I was able to re-tune without messing with the carb screw limiters.

Offhand I would say the saw cuts about 20% faster.


----------



## splitpost

Dude did the same mod to mine today and had to adjust carb but F:censored: wot a difference ,:jawdrop:In the pic ya posted it looks like she might be runnin lean or something,what fuel mix ya running?:greenchainsaw:


----------



## Dr. Hackemoff

splitpost said:


> Dude did the same mod to mine today and had to adjust carb but F:censored: wot a difference ,:jawdrop:In the pic ya posted it looks like she might be runnin lean or something,what fuel mix ya running?:greenchainsaw:



Splitpost - dunno if you are asking me but I run Stihl Ultra Syn at 40:1

Hack


----------



## tramp bushler

*Muffler Mod / heated handle bar*

I,m going to try it using steel brake line , @ -35 F or C for that matter a heated handle bar is just about mandatory ...... I should be able to find some kind of valve that will work for warmer weather ....... Or in the afternoons ..


----------



## tramp bushler

Can a guy use an ac arc welder with a small rod and low setting to weld on the muffler box ...?????????? ... 
Am still thinking on my handle bar warmer .. I think I will need a pretty good size hole in the handle bar to eliminate vibration from transfering to the handle bar ...
.
. I was thinking if I used Brake line , flared the end ,ran it from the inside of the muffler box out the side and into a hole in the handlebar ... I,ve got a half wrap handle bar for my 460 I,ll use as a guinea pig to see if the hole will substantially weaken the bar ... 
. I would weld the flared end to the inside of the muffler box ....
I have been thinking about a valve for warm weather . But I think the vibration would cause something to crack and break ..


----------



## splitpost

yeah,i get what your thinking,but 1st drilling the handle might weaken it,second,it'll need an exit point drilled down low on the handle and yes movement between the muff and top handle will cause probs unless you can find something flexible that won't turn to crap when subjected to hot gasses,we don't really have a need for heated bars here where i live but have u looked at the genuine stihl bar heater? :greenchainsaw:


----------



## tramp bushler

Ya , the factory ones are great . but the kit is around 300 bucks ... ... I can buy alot of something else with that . .. I was going to make the exit ,exguast point on the clutch cover side ....... It,s an experiment .. I,ve frost bit my hands a couple times and they hurt like hell when they get so cold ... @ 35 below , that cold happens often ............... If I toast a half wrap handle bar it sure won,t break my heart ...............


----------



## splitpost

go for it man ,let us know how u get on ,take some pics and post em


----------



## tramp bushler

*a Picture test*

See if this works ....




might work , lets see..


----------



## tramp bushler

Hey , I did it !!!!!!!!!!!!!!!!!!!!! Hipp Hipp HOORAYYY ......:jawdrop:... This is a summer time pic of my firewood logging equipment ........ Have brought out about 50 cord of wood with the trailer , but the axles are in bad shape ...... 
P.S. I know this is the muffler mod therad ,, But it was available without waiting once I got the Pic up loaded . I,ll go to the loggin show and post some more pics now ....


----------



## splitpost

neat looking trailer,not scared to load her up i see.:greenchainsaw:


----------



## Spitzer

*Hidden muffler mod*

Here's a pic of my MS341 muffler mod. 
Simple but effective, only tool i used was a dremel with a 5mm high speed burr then finnished off with a not so aggresive diamond to de-burr the inside, then flushed with brake cleaner and comp air before fitting back on the saw. Outlet holes are only about 1/4" dia, could go bigger if needed but i'm well happy with the result, i can tell the difference in the cut.


----------



## tramp bushler

asthesun said:


> reposting since noone's answering in other post


.. That ought to work .... reassembly the saw and give it a try .


----------



## Paul Dyar

Has anyone ever did an adjustable muffler mod,so you could fine tune it?


----------



## 820wards

Four Paws said:


> Well, maybe the moderators can sticky this thread, or something - I hope it can grow into a good bit of information, sort of like a reference guide, that folks can use to find info on modding their mufflers, rather than seeing a new post in the forum every other day.
> 
> Here is a muffler I fabricated for the mill I'm building. I am using an 820 PowerBee motor, 135cc, as a power head for the mill. I had to build an exhaust pipe so I was able to have it exit away from the operator as it is running. The exhaust port on the motor is 2-1/2" long and 1" wide. I cut the flange out stainless steel with a plasma cutter and the pipe pieces from a piece of 2" diameter muffler. When I flattened the 2" pipe it spread out to the 2-1/2" I needed for the flang. I also built the spark arestorer from a piece of stainless steel screen mesh rolled up to fill the 2" diameter end. I used some additional SS screen mesh to make a containment screen and then made a containment strap from some 18 gauge steel that I used like a hose clamp to hold the screen on the end of the pipe. It holds the rolled up screen in the pipe. I used SS screen because it will never melt with the heat of the exhaust. I'm hoping it will sound real good!
> 
> Just another type of muffler mod if you want to call it a mod.
> 
> jerry-


----------



## Oldbustedsaws

I call it the "Monster" mod cause it reminds me of the monster energy drink logo  Runs like a top!


----------



## Oldbustedsaws




----------



## 820wards

Busted Saws,

I see that you have header wrap on your bike exhaust. I've been thinking of adding it to the exhaust pipe on the mill I'm building. Can you touch that pipe when the exhaust pipe is up to temperature?

jerry-


----------



## rbtree

I think that adding holes to the air filter cover is only going to mess up the air injection system, and will result in clogged filters.

All my Huskys stay very clean......no need for added airflow, especially as I stated above.


----------



## Oldbustedsaws

rbtree said:


> I think that adding holes to the air filter cover is only going to mess up the air injection system, and will result in clogged filters.
> 
> All my Huskys stay very clean......no need for added airflow, especially as I stated above.



I'm planning on putting a screen in behind the holes, just haven't done it yet...

820wards, With one wrap it's touchable, two layers you can grab it with your bare hand, highly recommended.


----------



## SAW4FUN

Well I'm thinking about a muff mod to my 372xp. I've been reading different threads but was curious if you can just open up the factory hole or if you have to drill another? Thanks Alot f/ all the great info


----------



## tramp bushler

If you add a pipe port on the left side of the saw you will have a hand warmer for when you are falling .....


----------



## pwoller

SAW4FUN said:


> Well I'm thinking about a muff mod to my 372xp. I've been reading different threads but was curious if you can just open up the factory hole or if you have to drill another? Thanks Alot f/ all the great info




Here is my 372xp bb muffler mod. Still in the rough stage but I cleaned it up and painted it. Seems to have done the trick. Now I have to port it and advance the timing. And you can tell what saw I'm thinking of getting in the near future.


----------



## injun joe

ok was hopin you guys could post yur pics of a stihl 441 modded? im not really looking for a power increase i just want my saw to sound like its got a pair. sadly to say my ms 390 sounds like it would eat the 441.


----------



## tramp bushler

The 441 does sound like a wus , and it weighs 2 lbs more than an 044 , which is a way better saw , execpt in the vibration department ....... I tire of an overly loud saw . I used to take the whole front off the muffler on a few saws ..


----------



## MnSam

*025*

Is it correct of me to say that I should not mod the muffler on my 025 if it only has the L adjustment on the carb?


----------



## isaaccarlson

*Wow!!!!! Power, power, power!!!!!!*

Just ported my 390 muffler and HOLY COW!!! That thing MUST be pushing 6-6.5 HP!!! It won't stall in elm with 20" bar and full chisel chain with depth guages a little deeper than stock.and thats when I HANG on it!!!:jawdrop: It's just raw power......had to run the port off to the right, above the stock port because of the saw design. THANK YOU LAKESIDE!!!!!! I am going to do this to all my friends saws too....:greenchainsaw::greenchainsaw:


----------



## StihlyinEly

Four Paws said:


> Some Stihl saws can also be equipped with a factory dual port muffler cover which usually makes any additional muffler mods unnecessary for most folks.



Does anyone know whether these are available for the MS290 and 028AV saws? And am I reading it right that if these are installed a muffler mod probably is not needed?


----------



## ironman_gq

Only available for the 044/046 and 660 as far as I know I do know they don't have them for the 028/029 your on your own for these but they mod pretty easy


----------



## StihlyinEly

Thanks ironman.


----------



## isaaccarlson

*Here are some pics of my 390 muffler mod*

its not on all the way because there is still metal dust in it.
View attachment 112898

View attachment 112899

Now for the black stove paint.....


----------



## isaaccarlson

*Here it (390) is....with 1500 degree exhaust paint*

Cooked it in the grill on high for almost an hour and a half.
View attachment 113102

View attachment 113103

View attachment 113105
:greenchainsaw:


----------



## injun joe

isaaccarlson said:


> Cooked it in the grill on high for almost an hour and a half.
> View attachment 113102
> 
> View attachment 113103
> 
> View attachment 113105
> :greenchainsaw:



looks good. i know when i opened mine up there was no comparison. my uncle had a 390 and we went out cutting his non modded 390 couldnt keep up.just out of curiousity does yur 390 sound like its got a pair? i know mine does almost like it better than the rest of my saws.


----------



## bamatj

Howdy, chainsaw newb here. Does anybody have any details on muffler modding an echo cs400? I searched and seen a few people have done this but I didn't see any pics or details. I have no problem cutting it apart, but it would be nice to hear of a proven mod, since its a $50 muffler. Thanks.


----------



## SXSMAN

*Day late/dollar short*

Wish I'd known about this forum some time ago . I did try to buy a book off of ebay " How to modify your chainsaw muffler " but never received the book only to file a dispute to get my money back .

I've also seen and known of " Walkerized " saws for some time but had the pleasure of meeting Don Walker this last summer when I was on Vancouver Island and also his lil dog Tim ( Timber , 150 lbs Siberian Husky , part dog-part pony- I swear ! ). Not to slight Don but I may have made mods to my saw first before sending it to him . As a Euro auto mechanic for over 25+ years we have a very nice machine shop to even make a muffler from scratch . Might have been fun to work on the 394 but there will be other saws ......

Should have my 394XP back from Don in a couple of weeks .

Some repairs and mostly mods were done .

I plan on replacing the 350 with an XP , but may play with some mods on the muffler first thanks to this forum and thread .

Just wanted to say hey and thanks for a good source of info .

SxS


----------



## Ilie

*more power needed here in Romania also *

this thread caught my attention on the first read. This is also my first post here, so cheers to every enthusiast on here. glad I've found this comunity.

I've opened the exhausts on my dirt bike, on my cars and I said why not on the chainsaws. So, my first one that got the muffler mod was the Husqvarna 575XP. I know that there weren't so many modded mufflers on these, but I tried and did it. It performs better than before but also MUCH louder, it screams like a 2 stroke MX. though, I'm looking forward to see if I can get fix it with a black ignition module from 372, cause I couldn't get just 13600rpm. otherwise, I love it!!
I was basically ported the actual 4 inside openings of the firewall that its inside of the muffler, sorry no picture for that. and then added on the lower side of the muffler 2 pipes, and had them angled cutted inside and outside and also got it painted with a thermal paint.

















then I went further with the next chainsaw that I have, its called Partner 352 (same as Poulan 2250 and other), its a small cc chainsaw that I used in my garden from time to time. 
we did porting for the first time on this one. have to say that we didn't do NOTHING on the timing because we have to figure out first how to do it. we've opened the intake and the exhaust side quit a few milimeters. then I did the muffler job, which looks great. It performs way better, and it revs quicker. I just did some carb adjustments cause on first start it stayed higher on rpm, and didn't do it good on high rpms. It still didnt went upper than 13400rpm. I need to get more into this one for sure, but for now it outperforms ANY of his twin brothers 
also, any suggestions are welcomed.


----------



## MnSam

*029 muff mod*



StihlyinEly said:


> Does anyone know whether these are available for the MS290 and 028AV saws? And am I reading it right that if these are installed a muffler mod probably is not needed?



Just did a muffler mod to my 029 this afternoon, can take a few pics and put them up for you if you think it would help. It was fairly simple, and didn't take too long (no welding involved). It is definitely more peppy.


----------



## MnSam

Muffler mods look sweet! Nice welding job.


----------



## voxac30dude

my homelite saw has a cover on the muffler. it's a separate piece of flat steel thats cover the actual muffler. do i need to keep it on? will it make my saw run better if i take it off?


----------



## Ilie

MnSam said:


> Muffler mods look sweet! Nice welding job.




thanks.
I wanted to do a TIG weld, but didn't had one. still went good after all.

thanks.


----------



## MnSam

voxac30dude said:


> my homelite saw has a cover on the muffler. it's a separate piece of flat steel thats cover the actual muffler. do i need to keep it on? will it make my saw run better if i take it off?



What model homie? Add a pic or two.


----------



## voxac30dude

it's a 33cc ranger. model nuber is UTC10532 it has a 16 inch bar. i belive it's a 2006 model.


----------



## MnSam

If it looks like pic #1. I would proceed as follows:

1. Remove the muffler and seperate the plate as in (pic #2).
2. Using a needle nose pliers remove the spark screen from inside the muffler as in (pic #3).
4. Cut out the oval from the center of the plate.
5. Flatten out the screen to create a sheet of screen, single ply.
6. Cut the screen to size so that it fits behind the plate.
7. Reassemble together muffler/screen/plate.

Note:
- You must adjust the carb after this mod (especially the high adj. screw).
- This may significantly increase the noise of the saw as well, but it should increase performance.
- I didn't complete the mod on my saw as I am selling mine as is.

If this isn't your muffler let me know, I'll try to find another.


----------



## MnSam

*029 mod*

I cut out the center recess behind the deflector, opened up the deflector plate, and added another deflector fabricated out of drywall corner mold. Not especially sturdy, but at least gives me a template for something more permanent.


----------



## voxac30dude

does prying open the muffler exhaust port and making it bigger make any difference to the saws performance? and while we are on the homelite subject.

i dont see any stihls or husqys with sluts like this one. goes to show chicks dig homelites.


----------



## MnSam

I haven't done a muffler mod to a homelite, but the other saws I did it too sure made a difference.


----------



## Bulgie

*ms 390 mod*

i own a stihl ms 390 and i would like to do a muffler mod. what is the biggest size hole i should use?? i dont want to go too big and ruin anything.


----------



## isaaccarlson

*My 390 does sound like it has a pair (cuz it does)*

I used a piece if 1/2 inch electrical conduit but it measured about 5/8 ID. Pointed it to the right along with the factory outlet. I just cut a 65 inch silver maple down with it and i can not complain about a thing. I filed my depth gauges down about 2-2.5mm and I run a 20" bar with full skip chisel chain and THAT BABY CUTS!!!! Kinda makes me want a 30" bar.......anybody got one to give away????? At one point I had 6 people from around town standing there watching me and I saw one guy pick his jaw up off the ground...then he came over and asked me when I was going to get to his trees.....I didn't even know him!!!! I got two dump truck loads out of that tree (took 7 hours to cut it all up)....now to split it. I opened up the holes in the baffle a little when I did the mod, but was wondering if anyone takes it out or makes them huge? Here's to woodcuttingitis.....*runs off to work on lathe* anybody got any mods for lathes????


----------



## VINIFIREWOOD

*Dolmar 540*

Any of you guys done a MM on a 540?


----------



## matt9923

Here is my 660 one. 





028 super





039






All are much much better saws with muffler mod!


----------



## matt9923

What kind of screen is used for spark arester?


----------



## the westspartan

tramp bushler said:


> The 441 does sound like a wus , and it weighs 2 lbs more than an 044 , which is a way better saw , execpt in the vibration department ....... I tire of an overly loud saw . I used to take the whole front off the muffler on a few saws ..



it is .6 lbs heavier than an 044 and stock to stock a 441 beats a 440/044 pretty easily. Vibes and filtration are far superior on the 441. I'm about to do a muffler mod on mine and get it woods ported:greenchainsaw:


----------



## WoodChuck'r

Yeah...

The 441 is a nasty saw. Mod that thing correctly and it should beat a 7900!


----------



## WoodChuck'r

Well, a *STOCK* 7900 that is.


----------



## ncdodgeman20

*muffler mod*

this stuff is great i have a mcculloch pro mac 700 would it benifit any from this if so what would be a good way for going about it on this model of saw???


----------



## ncdodgeman20

*stihl 025*

has anybody ever done this to a stihl 025 if so how big of a hole did you make and did you do anything to the baffle??


----------



## dewclaw

*268XP Muff Mod*

This is the result of what I did to clean-up to the original muffler mod. 

I was impressed with how much more air/fuel I could crank thru my saw after the original mod not to mention the nice performance increase.

It wont add anymore poop to the saw it just increased the coolness factor a notch or two.


----------



## matt9923

dewclaw said:


> This is the result of what I did to clean-up to the original mukfler mod.
> 
> I was impressed with how much more air/fuel I could crank thru my saw after the original mod not to mention the nice performance increase.
> 
> It wont add anymore poop to the saw it just increased the coolness factor a notch or two.



pretty smart, no welding or brazing involved.


----------



## Metals406

ECRUPPRECHT said:


> you can do it with mapp gas but you have to get a good adjustable mapp torch in the 60 dollar range it does not work that great tho it kinda clumps up and looks like a s****y weld but its strong. if you can clump enough on you can go back with the torch and kinda melt it down some more and smooth it out a little. then take an angle die grinder with some roloc pads and smooth it out some more, moral not the best not the smoothest but it works and sure beats spending 500 bucks on acetylene torches, lucky for me i already have a set, anyone interested in muffler mods I will do it for you i have done many and they have all turned out very good, im not trying to get rich or anything like that just tryin to help a few good men out let me know pm me or something and we can work together on a price and what you are looking for I have a few pics of mufflers i have done if interested



You're new, so I figure I should tell ya. . . Selling muffler mod services without being a Site Sponsor is a bannable offense.

If you want to sell your services, look into being an AS Sponsor. . . Just trying to save you a banning.


----------



## ECRUPPRECHT

Metals406 said:


> You're new, so I figure I should tell ya. . . Selling muffler mod services without being a Site Sponsor is a bannable offense.
> 
> If you want to sell your services, look into being an AS Sponsor. . . Just trying to save you a banning.



I appreciate the looking out but im not really into making money on here honestly i would just recoup shipping charges to help a few people out that dont know how or have the tools to do the work, I am pretty new to the site and would hate to banned because this is a wonderful site, The GF does not think s tho.. should I delete my post???


----------



## Metals406

ECRUPPRECHT said:


> I appreciate the looking out but im not really into making money on here honestly i would just recoup shipping charges to help a few people out that dont know how or have the tools to do the work, I am pretty new to the site and would hate to banned because this is a wonderful site, The GF does not think s tho.. should I delete my post???



Naw, I think you're safe. . . Just thought I'd give you a heads up. . . Not a lot of new members know the site policies.

I think you'll be okay if you're just recouping your cost. . . But I'd check with a site moderator just to be sure.


----------



## banjobart

My Spitzer style 361 muffler mod is working just fine. Thanks for the idea!


----------



## billmartin

*257 husky muff mod?*

I searched this thread and couldn't find a pic or description for the 257/ 267xp

Did I miss it or is there one here with a similar muffler?

This is looking to be next weeks project


----------



## constantine

*390 xp*

I searched this thread and could not find anything about muffler modding the Husqvarna 390XP. Has anybody done one? How big a hole did you use? I am thinking 5/8 to 3/4 ID in addition to the stock outlet.
Thanks in advance.


----------



## Marlin.45

Here's mine on my Husky 350.

Fired it up tonite for the 1st time with muffler mod fitted. It was late so didn't want to upset the neighbours (though garage is underground). First impression was it was so much easier to start and when shut down after 10 seconds restarted with only a 3-4" of pull! ....and it rev's a lot easier. H mix tweaked 1/4 turn ACW - but that is as far as it will go and then hits the cam stop (see pic).

Original exhaust vent and spark shield are still there. No risk of spark causing an issue here. It's too bl**dy wet 







Off work Sunday and weather permitting I can to go and hack some more of my fallen 'firewood tree' up. So I can give it a proper test.

It is louder but not a whole lot.


----------



## ECRUPPRECHT

constantine said:


> I searched this thread and could not find anything about muffler modding the Husqvarna 390XP. Has anybody done one? How big a hole did you use? I am thinking 5/8 to 3/4 ID in addition to the stock outlet.
> Thanks in advance.



i did a 385 a "walkerized" style port i used two 5/8 tubes at the top of the muffler angled to the sides. i can get pics of it if desired


----------



## ECRUPPRECHT

pics of the 385xp i did


----------



## constantine

ECRUPPRECHT said:


> pics of the 385xp i did



Very nice !!
I'll send some pix of my mods later today.


----------



## flashy

I'm no expert, but shouldn't the openings to mufflers be pointing down, so as to discourage debris from entering the machine?


----------



## constantine

flashy said:


> I'm no expert, but shouldn't the openings to mufflers be pointing down, so as to discourage debris from entering the machine?



Good point, but I think that any chips would have a tough time getting in there, especially when the saw is running. Also, if you have a screen, nothing will get past it.


----------



## ECRUPPRECHT

flashy said:


> I'm no expert, but shouldn't the openings to mufflers be pointing down, so as to discourage debris from entering the machine?



ive never had a problem with that as the factory ports never angle and most people take out the screens. if the saw is running nothing will get in there at all and as long as your not storing it in dirt you wont have any problems


----------



## flashy

ECRUPPRECHT said:


> ive never had a problem with that as the factory ports never angle and most people take out the screens. if the saw is running nothing will get in there at all and as long as your not storing it in dirt you wont have any problems



.....or get caught in the rain.


----------



## gee_dubya75

*break in?*

should I allow my saw to 'break in' before I perform this mod on my 361? If so, how many tanks of fuel should I run through it first? 10-15?


----------



## 2000ssm6

gee_dubya75 said:


> should I allow my saw to 'break in' before I perform this mod on my 361? If so, how many tanks of fuel should I run through it first? 10-15?



That could help if any problems arise during break in. A modded muffler "might" cause your warrenty to be void, depending on the dealer. 8-10 tanks will be fine for break-in.


----------



## Marlin.45

....or leaving it in the vicinity of small frogs and similar


----------



## jimdad07

To Haywire:
I do refrigeration work on commercial and industrial equipment for a living. There is a lot of need for brazing because of the pressures of the refrigerant, especially one like 410a that runs at pressures twice as high or higher than conventional refrigerants. The point of all this is that Mapp gas can be used to braze if you have the right torch. I tried to use mapp gas with a bernzomatic torch that I had bought for a propane cylinder. I had no luck. Then I bought a Lenox torch head that has a very large tip on it. I can braze up to 3/4" pipe with silver bearing brazing rod with the Lenox torch head and mapp gas, it is more affordable than a b-tank and turbo-torch setup, but if you have to do it a lot, there is no sub for the b-tank with turbo torch or the oxy accet. torch.


----------



## voxac30dude

can someone please help me figure out how to mod my 435. i know how to braise metal and weld but have never modded a chainsaw before. i was thinking of doing a muffler mod to my huskvarna 435 41cc. should i port it and where would i do it on the muffler? pics if you can help a brotha out!


----------



## Machold

*Stick Welder*

Reading the posts, I don't see (or haven't read of) anyone using an arc welder to add the ports. Is there a reason? I'm very amateur when it comes to welding and own a Miller arc welder only.


----------



## matt9923

Machold said:


> Reading the posts, I don't see (or haven't read of) anyone using an arc welder to add the ports. Is there a reason? I'm very amateur when it comes to welding and own a Miller arc welder only.



It's hard to weld sheet metal with stick. 

onley way to get good at welding is practice and lots of it.


----------



## Machold

matt9923 said:


> It's hard to weld sheet metal with stick.
> 
> onley way to get good at welding is practice and lots of it.



Thanks, you're right, of course. I guess the simplest mod is a hole with a screen.


----------



## matt9923

Machold said:


> Thanks, you're right, of course. I guess the simplest mod is a hole with a screen.



yup, you could pick up a small mig for sheet metal pretty cheap. Or get a good torch with map gas and braze it. The cheap torch heads don't always work for brazing. If i were better at welding I would have you send me it but i'm not happy enough with my welds. 

This is my 660, I mig'd it, came out OK.


----------



## isaaccarlson

*I used a mig on mine, then used 1800° header paint*

and baked it in the grill for an hour. Used 5/8 electrical conduit with the coating ground off.


----------



## nanuk

*Where do most modders like their port to face?*

I've seen some that blow over the chain, on the chain, over to the off side, up, down....

any pro/cons for direction?


----------



## matt9923

nanuk said:


> I've seen some that blow over the chain, on the chain, over to the off side, up, down....
> 
> any pro/cons for direction?



Mine blows to the left and down, work's pretty well. You have to experiment, its only metal.

Some just open up and add the port where the factory one is, they look really good. I had to figure out what I wanted and go with it.


----------



## war-wagon

*ms290 mod*

so i'm stuck at work today and it's as slow as can be. reading on here and getting excited to modify the muffler on my 290. what exactly do i have to do to the carb when i'm done. high end? low end? please help, i dont want the mouthbreathers down in the valley to hear my saws final war cry echo off the mountain before i inadvertenly do some engine damage.


----------



## matt9923

war-wagon said:


> so i'm stuck at work today and it's as slow as can be. reading on here and getting excited to modify the muffler on my 290. what exactly do i have to do to the carb when i'm done. high end? low end? please help, i dont want the mouthbreathers down in the valley to hear my saws final war cry echo off the mountain before i inadvertenly do some engine damage.



adjust the carb, lots of threads on it.


----------



## war-wagon

i realize i have to adjust the carb, and i got the high end and low end sighted in. am i right to think i have to go counterclockwise with the high end? what about the low end? what am i listening for? maybe it's better to ask what am i feeling for since i'll probably be deaf as hell once i mod the muff.


----------



## matt9923

war-wagon said:


> i realize i have to adjust the carb, and i got the high end and low end sighted in. am i right to think i have to go counterclockwise with the high end? what about the low end? what am i listening for? maybe it's better to ask what am i feeling for since i'll probably be deaf as hell once i mod the muff.



One of the threads has a sound recording and Brad has a good video.


----------



## war-wagon

thanks, i'll try searching for it. but if you've got the link lying around that'd be great. and who is brad?

:monkey:


----------



## tramp bushler

Prolly not mr pitt. sorry , just jokeing ... You don,t want your chain to spin , You don,t want it to whine at the top end ... It won,t take much adjusting .. basically it will give you a little more torque and a little more POP ......


----------



## war-wagon

thanks i'll give her a go


:greenchainsaw:


----------



## bigjeepmudder

[/IMG]
Now that i finally figured out how to put pics up, here are some of my 621 with a slight but effective muffler mod.


----------



## matt9923

bigjeepmudder said:


> No that i finally figured out how to put pics up, here are some of my 621 with a slight but effective muffler mod.



as long as it don't burn the wood.


----------



## bytehoven

I was interested in hearing about shops I could send a muffler to be modified.

Walker in BC is one such shop, but would love to hear about others or if any members would consider taking on the mod.

I understand I could port it myself, but I was interested in a cleaner, welded look.

If I can't find a shop to help me with a welded mod, I figure I will order these Husky parts for $30, and do it myself.


----------



## bytehoven

I ordered the deflector, screen and mounting screws today.

I have noted Lake say the muffler body metal is a tad thin. 

Should I rethink using the sheet metal screw approach for securing the deflector/screen?

I thought it might be easy to drill & tap holes and use a couple of small bolts/nuts instead. Once installed, I could trim off any excess bolt protruding past the nut for a clean look.


----------



## Lugnutz

*Jd cs56*

I've seen some cool mods but it seems like alot of fabrication to clear the chain brake. Why not use the existing access hole in the front of the muffler



and drill a hole in the blocking plate




and then sandwich the spark arrestor screen between the two?

Any thoughts welcome !!


----------



## TommySaw

bytehoven said:


> I was interested in hearing about shops I could send a muffler to be modified.
> 
> Walker in BC is one such shop, but would love to hear about others or if any members would consider taking on the mod.
> 
> I understand I could port it myself, but I was interested in a cleaner, welded look.
> 
> If I can't find a shop to help me with a welded mod, I figure I will order these Husky parts for $30, and do it myself.



this has gotten me to jump the fence into the muff mod world, nice and easy and looks stock. Gonna order up 3 sets, by feb. I should be all modded out.


----------



## bytehoven

TommySaw said:


> this has gotten me to jump the fence into the muff mod world, nice and easy and looks stock. Gonna order up 3 sets, by feb. I should be all modded out.



These are Husqvarna parts by the way.

I plan to see how these parts might work on both my 192T and 211 and then possibly mod them. However, my main purpose to mod the 361 was for more power pulling the 25" bar with RSC chain.

I may run the 361 stock with the 20" bar, but install the modded muffler and retune when I want to run the 25" bar. The 361 ability to pull the 20" bar is fine and I'd prefer the quieter setup. 

I'll post pics ASAP.


----------



## constantine

That works very well. You see it on Husqvarna saws which have the front mounting bracket. Drill 2 or 3 holes and sandwich the screen. If you want to get up to a muffler exit area of 85% of the exhaust port area, there may not be enough room on the mounting bracket. Everybody has their own way to do it.


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## Lugnutz

constantine said:


> That works very well. You see it on Husqvarna saws which have the front mounting bracket. Drill 2 or 3 holes and sandwich the screen. If you want to get up to a muffler exit area of 85% of the exhaust port area, there may not be enough room on the mounting bracket. Everybody has their own way to do it.



I'm pretty sure that the original muffler opening + that big hole in the front will plenty exceed the 85% exhaust port rule.

Reason I was thinking about this as an option is that once the saw is put back together you'll never notice any extra work done on it...sleeper saw! 

I'm off to do some research and then I'll be back with pics!!!! These really cold days give me way to much time to get into trouble :greenchainsaw:


----------



## Lugnutz

*I Did It!*

stock muffler hole and cover










I didn't want to mess with fabricating a new exhaust pipe and wanted to keep the stock look so I modified the following




this is the cover that blocks the access hole in the muffler




this is the access hole
and this is the modified piece








I may have opened up too much, but the area I cut out was a bump..see pic above and you can see the detent that I removed. I'll have to go back in and measure and more than likely weld the hole back shut partially
After cutting away the detent/bump I placed the access blocking plate back on the saw and then put my spark arrestor screen over it and used the heat shield to clamp the screen in place









Hmmmm..what mod? Clean stock look.


----------



## constantine

Looks good! Very low profile. How does the saw run?


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## Lugnutz

I won't fire it up till I get all my measurements taken and double check the opening to make sure I didnt go to much.


----------



## Lugnutz

*sorry took so long*

Fired it up and it seems more lively, it has more jump in it when you gun it, and it sounds pretty nice, not too loud but it definately speaks to you. Not sure I'm gonna keep it this way as the heat sheild on the front now takes a direct hit and gets mighty warm, on the other hand it will keep your hands cozy in the cold! It sounds good and 4 strokes out on the top end. Still need to adjust the low end down a bit as the chain sporadically turns ( now and then..not constant ) and I need to get it into some wood.

How I did it:
I measured the exhaust port on the muffler..not the cylinder. The port on the muff is larger than the cylinder so I cut back my measurements in hopes of erroring on the small side. Then I measured the original muffler outlet ( not the hole but the deflector holes ) and the new opening and made sure to err on the large side, ie measure the longest point of the opening and the widest, despite the fact that my new hole wasn't even nor are the holes in the factory deflector. When I was done I was still below the 85% margin, enuff so that I could put a 1/4" square hole in the muffler and still be in the safe zone! And the best part is the looks! Guess you could call it a sleeper, better get the 62cc slug and jug and port it and leave all the badges on it, stating its a CS56 LOL


----------



## dan365husky

*screen help i already modded mufflers thanks !!!!!!!!!*

i have two 365 specials with dual pipe muffler mods on them i think they are similar to a walker style mod but have no screen on them. im a little worried about stuff entering the mufffler than getting into the cylinder when the saw is not in use i did not think about it until just lately but lets say i was using one and the other i happen to have just sit their whats to say i dont get some saw dust on it. anway can someone dirrect me on how to find a thread or source for the screen style i could install in the pipes with a clamp to hold it in. hey also just picked up a dolmar 5105 brand new i thought i was buying a 5100 but i dont think the dealer has any 5100 left. should i wait to mod the muffler on it until the warranty is up. it has a cat style muffler.


----------



## Lugnutz

try McMaster.com for screen or maybe even Graingers.

I've never used the warranty on my saws, how long is the typical warranty and if you are just cutting wood how much will you really use it during the warranty period? If its a year warranty and your just cutting wood for yourself chances are good that during the warranty you will barely get it broke in real good. I'd lean toward the "go ahead and mod it".

Rick


----------



## dan365husky

*muffler mod on a dolmar 5105 how do you do it ?*

it is a one year warranty i think i will go ahead and mod the muffler. it looks like i can just bend the top cover lip over and take the 2 halfs apart and remove the cat and internal. is that the correct way to mod the dolmar mufflers. i have only modded a couple stihls and 5 husqvarnas. this is my first ever dolmar everyone talked like the 5100 was the to have and i sold off a 353 and a 350. kept one 353 that runs better than the 5105 i bought but the 353 has a muffler mod.


----------



## constantine

dan365husky said:


> it is a one year warranty i think i will go ahead and mod the muffler. it looks like i can just bend the top cover lip over and take the 2 halfs apart and remove the cat and internal. is that the correct way to mod the dolmar mufflers. i have only modded a couple stihls and 5 husqvarnas. this is my first ever dolmar everyone talked like the 5100 was the to have and i sold off a 353 and a 350. kept one 353 that runs better than the 5105 i bought but the 353 has a muffler mod.



You may be able to order the OEM muffler that fits the 5100/5105 (not catalytic) and then do the mod on the spare. That way, you still have the cat muffler if any warranty issues come up.

I also like to order a separate muffler to do the mod, just in case I mess it up.


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## dan365husky

how can i know for certain on whether the replacment muffler will have a cat in it all the online sources for parts lookup do not list the 5105 what other saws have the same muffler as the 5100 and 5105 maybe i could figure what part # to order that way. i think i will buy a different muffler and keep the factory just in case i ever had any warranty concerns.


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## bartch

*muffler mod on a Dolmar 115i, any sense or not?*

Hi all,
i recently bought my first Dolmar (115i, same as the makita DCS5200i), it was a real bargain (it was used, but i could get it for 150 Euro) and it's in good health.
I was wondering, since i read that the 115i is a powerfull saw already, does a muffler mod is of any use? Can i gain more power with such a mod?

Thanks,
Bart


----------



## constantine

bartch said:


> Hi all,
> i recently bought my first Dolmar (115i, same as the makita DCS5200i), it was a real bargain (it was used, but i could get it for 150 Euro) and it's in good health.
> I was wondering, since i read that the 115i is a powerfull saw already, does a muffler mod is of any use? Can i gain more power with such a mod?
> 
> Thanks,
> Bart



Hello Bart and welcome to AS. 

Generally, any saw will benefit from a muffler mod. There are many threads here showing how to do it. Just use the "search" tool to find them.

Congratulations on the new saw. There are many people on here who are fans of Dolmar. We do not have as many dealers in the US for Dolmar as we do for Stihl and Husqvarna, but the people who use Dolmar really like them. I got my first one, a 7900, when a local shop added the Dolmar line. They give good service and the saw is excellent.


----------



## gee_dubya75

*Silver brazing*

Has anyone ever silver brazed the tube onto the muffler before? I'm thinking about trying it when I mod my MS 361 but obviously don't want it falling off the first time I get the muffler hot. Also, what is the typical temperature of the exhaust once everything gets warmed up?


----------



## mustangwagz

*Carb Tuning, AFter the mod*

ok..well i can run and maintain saws fairly well in my opinion..but for as far as the H and L screws, ive never touched em... So, my question is, after i mod my muff (haha..i said muff..) How do i go about tuning my carb correctly? If i'm burning excess fuel, no biggie..i just dont wanna cook my saw...seeing as they're worth they're weight in gold since i heat with wood. I've got my baby 135 husky that imma mod. its a fast cutter, but cmon....even faster would be great.. and MORE LOUDER would be sweet too.. i like obnoxious sounding toys. lol 

Thanx guys!

-Zac:chainsawguy:


----------



## matt9923

mustangwagz said:


> ok..well i can run and maintain saws fairly well in my opinion..but for as far as the H and L screws, ive never touched em... So, my question is, after i mod my muff (haha..i said muff..) How do i go about tuning my carb correctly? If i'm burning excess fuel, no biggie..i just dont wanna cook my saw...seeing as they're worth they're weight in gold since i heat with wood. I've got my baby 135 husky that imma mod. its a fast cutter, but cmon....even faster would be great.. and MORE LOUDER would be sweet too.. i like obnoxious sounding toys. lol
> 
> Thanx guys!
> 
> -Zac:chainsawguy:



there are more then enough carb tunign threads, some with videos even. madsens has an audio file and a good wrigth up. 

http://www.madsens1.com/saw carb tune.htm


----------



## mustangwagz

Thank you sir! ...imma have to find a site for non pro saws with rpm suggestions. Also have to find me a single cylinder tach!


----------



## Metals406

mustangwagz said:


> Thank you sir! ...imma have to find a site for non pro saws with rpm suggestions. Also have to find me a single cylinder tach!



I bought my tach from Edge & Engine (site sponsors).

Here's their profile and web link: http://www.edgeandengine.com/webstore/wecs.php?/

http://www.arboristsite.com/member.php?u=14432


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## matt9923

mustangwagz said:


> Thank you sir! ...imma have to find a site for non pro saws with rpm suggestions. Also have to find me a single cylinder tach!



go to the "Beg for the manuals" thread and ask for you manual. it will have the tunign specs, they wont matter after you MM it so use madsens. You have to use your ear, not a #. A tach is good for after tuning to check and make sure something is int way off.


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## mustangwagz

yah imma grab a tach from work that we use for checking spindle speed. i'm sure itll work. Its gotta rubber tip that goes into the pilot hole on the crank shaft (or spindle) itll measure speeds from 0 to like 30,000 rpm. Maybe not as acurate, BUT free so itll get me close. Yah from what i've read on that carb tuning page, playin it by ear is how it'll get done.. With automobiles, i can pick outta problem easily...now its upto my senses to learn myself how to read saws as well.. Thanks guys!


----------



## mustangwagz

*Muff Mod on my 137 E-Series..*

Awww, he's just a lil guy..but Big at heart! lol did my mod, just gotta get my tach so i dont toast it. always did cut very good, but now it mowed through a white oak log about 12 inchs in diameter faster than ever before... I'm excited! 

AND OF COURSE, pic to go with my testimonial! lol aint pretty, but it works! Oh and by the way, pic was before i mowed the log in half, so now the pretty orange paint is scuffed. lol I tried...*sighs*


----------



## voxac30dude

check out his beauty!
http://www.youtube.com/watch?v=s_II4Fr8WoI


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## mustangwagz

So how'd that work out? you cut the muffler open or just punch holes in it?. Just curious, i got the 445 and was wandering if it had all kinda stupid #### inside the muffler like my little 137 did. Had a cylindrical thing with screen in it and an oval thing as well, all kinds of useless stuff. Only saved the screen from inside for the exit hole i made to keep sparks N stuff from gettin out..if it actually helps. i had to cut mine open, and mig it back together.


----------



## 02powerstroke

Anyone on here mod a MS 361? I'm looking to do this to mine.

thanks


----------



## 02powerstroke

Spitzer said:


> Here's a pic of my MS341 muffler mod.
> Simple but effective, only tool i used was a dremel with a 5mm high speed burr then finnished off with a not so aggresive diamond to de-burr the inside, then flushed with brake cleaner and comp air before fitting back on the saw. Outlet holes are only about 1/4" dia, could go bigger if needed but i'm well happy with the result, i can tell the difference in the cut.



whats that just taking the caps off?


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## constantine

02powerstroke said:


> Anyone on here mod a MS 361? I'm looking to do this to mine.
> 
> thanks



Here you go. Check on the "Lakeside53" sticky to see how to do it. It really works. Mod the saw, tune the carb, run about 8-10 tanks through and it's primo!






"MS 361 Lakeside-style muffler mod"


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## Junkrunner

Here's one, I did on my 036


----------



## rayvil01

*Oxy-Mapp Brazing?*

There were a number of posts about using Mapp gas to braze a mod onto the muffler. Sounds like some folks had success and some didn't. Yesterday I was in the hardware store and saw an Oxy-Mapp torch. Seems like that would be a good bit hotter burning than straight Mapp gas. 

Has anyone been using one of those for brazing muffler mods?


----------



## mustangwagz

rayvil01 said:


> There were a number of posts about using Mapp gas to braze a mod onto the muffler. Sounds like some folks had success and some didn't. Yesterday I was in the hardware store and saw an Oxy-Mapp torch. Seems like that would be a good bit hotter burning than straight Mapp gas.
> 
> Has anyone been using one of those for brazing muffler mods?






I've never used the brazing rods myself, i just used my mig. turned the amperage way down and just pretty much stitched it. (Stitching is what i consider several spot welds overlapping each other.) I had no problem with mine yet and i used the heck outta it yesterday.


----------



## constantine

*Oxy-MAPP Brazing*



rayvil01 said:


> There were a number of posts about using Mapp gas to braze a mod onto the muffler. Sounds like some folks had success and some didn't. Yesterday I was in the hardware store and saw an Oxy-Mapp torch. Seems like that would be a good bit hotter burning than straight Mapp gas.
> 
> Has anyone been using one of those for brazing muffler mods?



That is exactly what I use. If you burn straight MAPP gas, the temperature is really marginal for brazing. MAPP alone won't even melt a nickel-silver rod. Using the oxy-MAPP gives a higher temperature. The brass melts quickly and flows into all the crevices like it should. For $55 you can't beat the small oxy-MAPP setup. For ordinary soldering of copper pipe and the like, you just don't use the oxygen tank.

I've found that one of the factors in successful brazing is to use a low velocity flame. That way, the brazing liquid doesn't get blown around, and can seep in and fill all the spaces between the parts. Even when using oxygen, you have to heat the parts thoroughly before you touch the rod to the work. It should melt right away and the melt should flow freely, like water.


----------



## rayvil01

constantine said:


> That is exactly what I use. If you burn straight MAPP gas, the temperature is really marginal for brazing. MAPP alone won't even melt a nickel-silver rod. Using the oxy-MAPP gives a higher temperature. The brass melts quickly and flows into all the crevices like it should. For $55 you can't beat the small oxy-MAPP setup. For ordinary soldering of copper pipe and the like, you just don't use the oxygen tank.
> 
> I've found that one of the factors in successful brazing is to use a low velocity flame. That way, the brazing liquid doesn't get blown around, and can seep in and fill all the spaces between the parts. Even when using oxygen, you have to heat the parts thoroughly before you touch the rod to the work. It should melt right away and the melt should flow freely, like water.



Many thanks to you for the info. MIG is somewhere in the future. But, this Oxy-Mapp is something I can do right now.


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## ktmsooner

No, he didn't just take the caps off, look close and you will see the small holes that he made with a dremel tool.


----------



## Diesel Pro

Here's my 345 muffler mod. I slit the deflector on the sides and folded it back to minimize the welding. I have a Miller 250X and had a bit of trial and error geting it turned down low enough with the .030? wire.


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## Junkrunner

Here's my 365 with its "brazed" pipe.


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## o8f150

i bought a poulan tiger shark the other day just to use as a debranching saw,,,i only gave 50 for it,,,runs great for a used one,,so i figured i would try a muffler mod on it,,had nothing to loose,,,,the exit ports on this one is on the backside of the muffler,,,,when i pulled it apart the screen was on the entrance of the muffler,,,,so all i had to do was drill a 1/2 inch hole on the front side of the muffler and deburr it,,fired it up and the only adjustment i made was turning the idle down a tad,,,seems to run a little bit better,,not much louder either,,i wasn't expecting to much out of a 33 cc saw,,,ohhhh yea,,,for a used saw,,the piston looked dang near new,,you had to look real close to see the 1 small scuff mark,,,,guess i didn't go to wrong


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## halfskip

*how about ms362 mufflers?*

Would a ms362 muffler mod be the same as a ms361. I was thinking about the lakeside style muffler mod.


----------



## halfskip

*ms362 exhause port*

Also wondering if anyone has calculated the exhaust port area on a ms362 at the piston.


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## teatersroad

*346xp cat muffler mod.*

Knew little of muffler mods before joining this group, so thanks.

The photos should explain the method pretty well. Removed muffler, and from the cylinder side drilled out existing 1/8" holes to 5/16", 9 holes total, plus existing 1/8 holes I could not reach. The black tube you see flows from hollow chamber downstream of catalitic plate and out the exhaust. Could probably be cut to allow flow from the upstream side. 

For the additional port, I drilled a hole and tapped it to 3/8" mpt. At first I finished it off with a black pipe 3/8 to 1/4 bushing I had drilled out a little. Temporary as I tried to figure how I was going to get a spark screen in there.

That solution. 3/8" mp to 1/2" compression. I set the fitting; btw take care when drilling and tapping such thin walled stack. I'm impressed and comfortable with how much purchase I have with those threads.

Ground down the shoulder (?) of the compression nut so it would seat more fully. Set a #40 stainless aerator screen over fitting and locked into place with the compression nut. 

Total cost. Fitting $3.49, Screen 35 cents. I'm pretty happy with it. Not a lot of cool factor, but finished and servicable. As a coincidence my Husky scrench fits the compression nut.

Saw is modded in other fashions as well, but I'll share that in a thread when it's done.

Regards.


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## constantine

*NPT reducers*

I like your use of the NPT reducers, 'cause I use them myself. Do you plan to solder that brass fitting in place? I'm thinking that it may vibrate loose when cutting. The way you handled the screen is very neat.


----------



## teatersroad

constantine said:


> I like your use of the NPT reducers, 'cause I use them myself. Do you plan to solder that brass fitting in place? I'm thinking that it may vibrate loose when cutting. The way you handled the screen is very neat.



thnx,

seems like solder would be a good idea, wonder if I could sweat it in ??. The fitting takes up nicely, and have had it out a few times in my building it. solder or locktite at some point.

I haven't found again the usfs mesh req. for spark screen. hdwr. store had a variety. I cut on private mostly anyway, but a spark areester is wise at times.

I saw another npt used here at one point, maybe that was yours.

regards


----------



## matt9923

I wouldn't permanently attach it, you want to be able to clean the screen, that's one of the best parts of that mod.


----------



## teatersroad

matt9923 said:


> I wouldn't permanently attach it, you want to be able to clean the screen, that's one of the best parts of that mod.



Right, Its the fitting to muffler that gets soldered. Not the compression nut to fitting that holds the screen in place.


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## matt9923

teatersroad said:


> Right, Its the fitting to muffler that gets soldered. Not the compression nut to fitting that holds the screen in place.



ohh, makes seance. misunderstood ya


----------



## teatersroad

A person could use 1/2" mpt to 5/8" compression if they wanted a bigger opening. Aerator fits better there too, though trimming's no big woop.


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## constantine

*Great Idea*



teatersroad said:


> A person could use 1/2" mpt to 5/8" compression if they wanted a bigger opening. Aerator fits better there too, though trimming's no big woop.



I'm working on a 460 right now, and am doing an NPT muffler mod, as opposed to getting the factory OEM "fire-safe" (read "pre-EPA style") muffler. Think I'll try that compression fitting with the screen. When it's done I'll post a pic or two and let you know how it turns out. I'm planning to use a steel NPT for the piece that joins the muffler and oxy-MAPP braze it in place. We'll see how it comes out.


----------



## TFPace

*345 Muf mod*

I just finished my first ever muff job on my 345.

Thanks go out to Diesel Pro, Lil Possum and Brad Snelling for their excellent help, not to mention the stickys that get a fellow going in the right direction.

I just have to re-tune the saw and this mission is accomplished.

I really hate that this saw didn't have the Husqvarna 7ga. heavy muffler option offered in the earlier years of its production.

I have loaded the pictures to my photobucket account.

http://s1021.photobucket.com/albums/af336/Plasmaguy_1964/Husky%20345%20Muffler%20Modification/
Later,

Tom


----------



## Diesel Pro

Diesel Pro said:


> Here's my 345 muffler mod. I slit the deflector on the sides and folded it back to minimize the welding. I have a Miller 250X and had a bit of trial and error geting it turned down low enough with the .030? wire.



Finally got a good edge on the chain and got a chance to work it a bit today. Worked very nicely.


----------



## MS390

QUOTE=windthrown;1371281]But but but... where can I get a drill bit to cut an oval? Madsons? Harbor Freight? Does Stihl make one? :greenchainsaw:[/QUOTE]

:hmm3grin2orange::hmm3grin2orange::hmm3grin2orange::wave:[


----------



## Homric

*036 pro mod*

I recently mod the muffler and now I am getting sound like it is dry, no oil. The sound seems to be coming form the engine not bar. I did adjust the cab but not sure if it is right. Would to lean cause this? Any sugestions?


----------



## BarkBuster20

Homric said:


> I recently mod the muffler and now I am getting sound like it is dry, no oil. The sound seems to be coming form the engine not bar. I did adjust the cab but not sure if it is right. Would to lean cause this? Any sugestions?



I'm not into the whole "muffler mod" thing cause it isnt actually going to help your saw in big wood (big wood for your saw) but since you modded it it will be running lean, you need to richen up the carb a bit.


----------



## brokenbudget

I'm not into the whole "muffler mod" thing cause it isnt actually going to help your saw in big wood

wow, so everybody here thats done one (or a few) is just blowing smoke?


----------



## Kingsley

Anyone have any prictures of a muffler mod to a Stihl ms210 or roughly the same muffler style? I'd like to gather some ideas.
Thanks,
Marty


----------



## 2000ssm6

BarkBuster20 said:


> I'm not into the whole "muffler mod" thing cause it isnt actually going to help your saw in big wood (big wood for your saw) but since you modded it it will be running lean, you need to richen up the carb a bit.



So your 20" 3/8 equipped 026 does not have a muffler mod?


----------



## Pierreg

*Muffler mod.&welding type.*

With all the modifying here,can this be done with an AC welder? I assume that a wire feed or brazing is best?Can someone steer me where to study this more?Kind of like the muffler mod101?The saws run much better afterwards?I see that carbs need adjusting.I have an oxy/acetelene rig but have never brazed anything.Thanks for the tips.....


----------



## constantine

Pierreg said:


> With all the modifying here,can this be done with an AC welder? I assume that a wire feed or brazing is best?Can someone steer me where to study this more?Kind of like the muffler mod101?The saws run much better afterwards?I see that carbs need adjusting.I have an oxy/acetelene rig but have never brazed anything.Thanks for the tips.....



Go to the sticky on the Lakeside53 mod to check out the basics. There are a lot of good photos also. About the AC welder, I can't help you, since I use only gas. Oxy-Acetylene is great, but you have to keep the temperature down and not use too intense a flame. The key in brazing is to have a low-velocity flame to heat the workpiece, then touch the rod, and the brass or nickel-silver flows in to the spaces between the pieces to be joined - just like soldering only higher temp. and much stronger. I like to use oxy-MAPP myself because there is no danger of burning through the relatively thin sheet metal of the muffler. The oxy-acetylene works well, but you have to use a light touch. 

No matter what anybody says, muffler modding really increases the power. You can definitely feel it. You mod the muffler, then take the limiters off the carb, adjust to run richer, put the limiters back, and you're in business. I've modded some saws after 10 - 12 tanks, and some when brand new. No reason to wait. Just do it. You won't be sorry.


----------



## sbhooper

I have now modded all of mine and I have to say that to me, the most impressive is my little 260. It makes the 16-inch/.325 scream and the mod was super easy. I haven't pushed any of them too hard on the rpms, keeping them all tach tuned right around max suggested.


----------



## hooligan971

Been lurking here for a while and searched what seems like hundreds of posts but can't find info on muffler mod for ms441. Sorry if I missed something :monkey: but does anyone know a link to steps for the mod for this specific saw and carb adjustment that needs to be done after ?
Thanks


----------



## 2000ssm6

hooligan971 said:


> Been lurking here for a while and searched what seems like hundreds of posts but can't find info on muffler mod for ms441. Sorry if I missed something :monkey: but does anyone know a link to steps for the mod for this specific saw and carb adjustment that needs to be done after ?
> Thanks



I did one for a buddy using the "lake style" 361 pipe mod. I've seen the 288xp deflector used also but thought it was too tight of a fit. Here is the link(also at the top) to Lake's mod. http://arboristsite.com/showthread.php?t=33528 

You can place the pipe in the same area as the 361.


----------



## tawilson

hooligan971 said:


> Been lurking here for a while and searched what seems like hundreds of posts but can't find info on muffler mod for ms441. Sorry if I missed something :monkey: but does anyone know a link to steps for the mod for this specific saw and carb adjustment that needs to be done after ?
> Thanks



The first page of this thread has a post with a pic of one. Might get you started.


----------



## hooligan971

Thanks guys. I hadn't thought about trying a space between ms and 441 or simply searching 441. I ordered the screen and tube today for the 441 and I'm going to mod the 260 tomorrow. I've used stockers all my life but after reading all the stuff on here I've gotta at least try the muffler mods. I have 4 little Poulan 2000 top handles I use alot . Bought them at yard sales here and there and might have about $50 in them all together. They're actually good little saws for what I paid for them. I got one for $5 still in the box.Think I'll see what a mod will do for one of them.opcorn:


----------



## tawilson

hooligan971 said:


> Thanks guys. I hadn't thought about trying a space between ms and 441 or simply searching 441. I ordered the screen and tube today for the 441 and I'm going to mod the 260 tomorrow. I've used stockers all my life but after reading all the stuff on here I've gotta at least try the muffler mods. I have 4 little Poulan 2000 top handles I use alot . Bought them at yard sales here and there and might have about $50 in them all together. They're actually good little saws for what I paid for them. I got one for $5 still in the box.Think I'll see what a mod will do for one of them.opcorn:



Posting pics is a good way to make friends, especially if it involves a saw I also own.


----------



## jpj6780

*Question*

1. What do y'all think about threading the tip of the Lakerized muffler port so that it could be capped and re-tuned when a little less noise is better than a little more power?

2. Why not just go ahead an weld the new muffler port on instead of brazing? I know brazing is easier, but is there a reason that it shouldn't be welded?


----------



## Carl Anderson

Hi, I'm new to this site and been getting some great info. I'm trying to tune up and shake the cobwebs off of my Jonsered 2050 turbo. It's running OK and it has always been a good saw with good power and very quick acceleration for it's size (I didn't realize how good it is until I cut with my dad's cheapo depot box store saw - yuck).

So I put a new E3 plug in it and tweaked the carb just a bit and it's running pretty decent (needs a new chain too but that's a different story). I was interested in a muffler mod but didn't see anything on this specific saw. I don't have access to a welder and what little welding I've done is far from professional quality. So would I just be in over my head and better off leaving a decent running saw alone?

The saw was purchased new in 1995, is that pre EPA crapola?

Thanks!


----------



## ECRUPPRECHT

Kingsley said:


> Anyone have any prictures of a muffler mod to a Stihl ms210 or roughly the same muffler style? I'd like to gather some ideas.
> Thanks,
> Marty



you dont really have to add a port on that style muffler just open the existing one up a bit


----------



## Carl Anderson

ECRUPPRECHT, thanks for the info. For now I guess I'll leave it alone until it's running tip top and then maybe I'll open up the port a little and see what it does.

By the way, I didn't mean to put down the box store saws, they certainly have their place for the person who doesn't cut enough to justify spending a lot of money on a higher end saw (like my dad). Besides, it ran and cut in a pinch while my Jonsered was waiting for new gas lines and for me to clean it out after the person I lent it to put oil in the gas tank and gas in the oil tank. So I can't really say anything bad about the cheaper saw, it's just a big difference between the two.


----------



## rapidlee

*ms 200t 020t*

hello all.
i see the muff mods are on ground saws,
can anybody tell me if the mod will work on ms200t, i use my 200t daily and would love to squeeze a bit more power out of it.

pictures would be great


----------



## isaaccarlson

A muff mod will wake up any saw that has a choked up muffler.
if the saw is quiet, it's choked off.


----------



## gee_dubya75

*can't wait to try it now*

Well guys, I finally got around to cutting a hole in my muffler and brazing on the tube I made on the lathe. I pretty much followed Andy's instructions with the exception of the brazing part. Instead of using the regular brazing rod I decided to go with silver brazing instead. The advantage of silver brazing is that it wicks into the joint like when sweating copper pipe. Before I painted it you could hardly see the solder in the joint. Don't worry silver brazing won't remelt until the temp gets over 1100 degrees F so it won't fall off when the muffler gets hot. Here are the pics of the finished job. I fired it up and retuned the carb but I want to run it in some big wood now.


----------



## jpj6780

Well let us know how she runs.


----------



## SpaayDawg

*028WB "Front/downward" Facing Muffler Mod*

There seems to be more help on the side discharge 028 mufflers, so I thought I'd post what I did to my 028WB front discharge muffler. It is rather open to start, with only a shroud type of baffle entering from the cylinder. I drilled a 1/2" hole in it anyway.






Then I cut away the entire shroud on the inside of the spark arrestor screen plate.






I did this before even knowing I was "muff modding" my saw. Bent the exit shroud so that it was at the max opening allowable under the front cover.






The entire assembly on the saw. The exit is the max it can be without further modification. I left in the spark arrestor screen for a bit of back pressure. The saw itself is the smallest 028 made (42mm bore) but this mod allows it to pull a 3/8 16" b/c pretty well.






Hope that any one with this style muffler won't hesitate to complete this. It made the saw alot more throttle responsive, and earmuffs are almost mandatory!!


----------



## Gareth83

I have a Husqvarna 44

What can I do to the muffler on this one?










By my 'brief' calculations, the exhaust port at piston is ~230mm^2 (hard to calculate accurately)

So the ideal exit area would be between 184mm^2 and 196mm^2 (80 and 85%) 

the existing exhaust port is 113mm^2 so I'd need to drill an additional hole that would yield an area of ~70-80mm^2

Do I just therefore drill an additional hole of between 9 and 10mm in diameter?? If so where?

Or must I port out the existing exhaust to 15mm diameter?

There isn't a spark guard at present as my guess is due to the baffled design this takes care of its self internally

Finally, is it essential to have a tube fitted or would a hole just suffice?


----------



## Gareth83

any suggestions?


----------



## jeffro

*Altered Stihl 066 muffler*

So I got an 066 second hand, looks like somebody put an intake and exhaust on it! The OEM muffler is missing the cover??? The internals are complete, still has baffles and screens. Has the side port, maybe all 066 mufflers did though.

Can I just add a regular Stihl muffler cover to this?? The saw is a bit loud, and idles more like a Harley than a chainsaw, I think maybe they did not know what they were up to, or have it tuned for some oddball settings.

Still has plenty of power, I need to get a tach and fine tune things though. Trying to trade off the Max Flow filter and cover for a Stihl HD filter/cover too.

Thanks!!

http://www.flickr.com/photos/[email protected]/4514935836/
http://www.flickr.com/photos/[email protected]/4514935630/


----------



## SpaayDawg

jeffro said:


> So I got an 066 second hand, looks like somebody put an intake and exhaust on it! The OEM muffler is missing the cover??? The internals are complete, still has baffles and screens. Has the side port, maybe all 066 mufflers did though.
> 
> Can I just add a regular Stihl muffler cover to this?? The saw is a bit loud, and idles more like a Harley than a chainsaw, I think maybe they did not know what they were up to, or have it tuned for some oddball settings.
> 
> Still has plenty of power, I need to get a tach and fine tune things though. Trying to trade off the Max Flow filter and cover for a Stihl HD filter/cover too.
> 
> Thanks!!



I'd leave that sucker as-is. That's a "stock" factory dual-port cover. If you put a newer "stock" single port muffler/cover on it you will lose power. Wear some muffs and go cut wood!:greenchainsaw:


----------



## jeffro

SpaayDawg said:


> I'd leave that sucker as-is. That's a "stock" factory dual-port cover. If you put a newer "stock" single port muffler/cover on it you will lose power. Wear some muffs and go cut wood!:greenchainsaw:



Ahh, so that is what the dual port looks like, I was wondering if that was what it was. I was expecting even the Stihl dual port to have a full front panel on it, but had yet to find a real answer. Thanks!!

Trust me, I was wearing muffs, I think I might get some 30dB muffs.

It was going through 20-25 inch diameter dead red oak pretty well after I got the chain sharp....


----------



## Tiger Rag

OK, I've been a lurker on here for a while. Read this whole post and decided to go for it on my Husky 365 special. It ended up being pretty easy on this saw since it had a removeable spark arrestor screen. 

Started with this:






Removed the spark arrestor screen:






Took my cut off wheel and cut both sides of the deflector and heated it up with torch and bent it backwards:






Took my die grinder and removed some material from the original hole:






Heated the flap of the deflector back up and bent it back into place:






Took some thicker steel and cut pie shaped pieces on both sides (had to shape on side on the anvil to fit) of the flap so it could open wider and flow better. Tacked it with my mig to avoid distortion and blowing through thinner muffler steel. The thicker steel helped from blowing through. Seamed it up and came out decent with a little work from the grinder and a forgiving flap disk.


----------



## Tiger Rag

Taped up where the exhaust gasket mates and rattle canned it with some high temp bbq grill paint.











Finished product:











Back on the saw:
















Seems to run pretty good. Not as loud as I expected based on some other comments on here. Haven't gotten a chance to test in some cuts yet but I'll try and follow up when I do.

Thanks to all that posted their experience on here! Sorry for the poor quality cell phone pictures. It's what I had on me.


----------



## HittinSteel

Great job on the muffler and great choice in beer


----------



## Tiger Rag

HittinSteel said:


> Great job on the muffler and great choice in beer



I didn't think that would get bypassed without notice. It was Saturday after all..... 

Oh, and Thanks!


----------



## SpaayDawg

Tiger, impressive job!!  
I like the serviceable spark screen for sure!


----------



## Tiger Rag

SpaayDawg said:


> Tiger, impressive job!!
> I like the serviceable spark screen for sure!



Well, I wish I could take credit for that but we have to give credit to Husqvarna for that. That is a stock feature on my 365 Special. It just made my job easier and I was careful to retain it by not welding it closed. It can still be pulled and cleaned.


----------



## Tiger Rag

I should also mention that this muffler was a hollow can type. It has no internal baffles so I did not have to split it open to open up anything internally.


----------



## kraftzion

*Rat saw muffler mods*

I heated and spread the seam, removed the baffle, heated and recrimped the seam, drilled a 5/8 hole in the front, took a long radius 3/4 copper el and sawed it so it would lay flat against my muffler and brazed it in place. If you want to see it copy the following link and paste it into the address bar.


http://picasaweb.google.com/lh/sred...7393&authkey=Gv1sRgCO-Goeav5sup1gE&feat=email


----------



## frogg

*echo*

how do you do a muffler mod on a echo cs-400. ? searched but could not find any info.

maybe i did not search correctly.

thx, frogg


----------



## Meatco1

I'm wondering if anyone has tried this with a new MS362, or if it's even possibile? 

I don't have a clue as to what emissions restrictions they have on the 362 muffler, but supposedly, there are more than the 361s.

Thanks,

Richard


----------



## ric5141

*Poulan 4620 AVX*

I did a muffler mod to a Poulan 4620. I forgot to take pictures during the mod...doooh. Anyway I uncrimped the muffler using a screw driver to lift the edge around it. Rather then pulling the baffel I made it into Swiss cheese. I made a plate and used the original screws to eliminate the rear discharge. 

After a quick scrounge through the parts bucket i found a steel pipe that looked like it would do the job. I drilled out two 7/16th holes and brassed the Bologna cut pipes on to the muffler can. 

I recrimped the muffler case and sprayed it with black stove paint. After an adjustment to the carb I cut some wood with it. The saw really seems like a new saw except I really need to dump that POS safety chain!!! As far as sound this saw now sounds like a chainsaw should.


----------



## Gareth83

I have just bought a Dremel 300. What attachment do I need to rip open the muffler on my Husky 44


----------



## Tiger Rag

Gareth83 said:


> I have just bought a Dremel 300. What attachment do I need to rip open the muffler on my Husky 44



You might want to post a picture of the muffler on your 44 so those not familiar with it can still offer you advice on how to do it.


----------



## Gareth83

I've got a thread open just below this one


----------



## rpecinovsky

*MS 270 Muffler Mod*

Hey Guys
First post on this site been pretty interested in the mod threads some great info here. I was able to mod my ms270 by enlarging the existing port so the factory spark arrestor can still be used. I also was able to get the slant pipe welded on with an ac welder using 6013 rod running it at 50 to 55 amps. I do need to clean up the weld a little and paint it. I have two questions.
1. which high temp paint? the bake on or just spray on?
2. i'm still a little confused on the limiter caps for re-adjustment they seem to come out just a little bit i don't want to break anything.
Any advice would be appreciated thanks in advance.

I will post pics in the next day or two.


----------



## Tiger Rag

I just used flat black bbq grill paint. I had some laying around and it has worked well for me in the past. Readily available too.


----------



## Shin Barker

I've just finished reading this whole thread in one sitting, and now my mind in numb and my eyeballs are slushy.

At the beginning of this thread, it mentions the modified hole should be 80-85% of your exhaust port size.

But how does the current muffler hole size fit into the equation if you’re drilling new holes, as opposed to opening up your current sized blowhole?

‘fer instance:

Does ‘X’ (current size) + ‘Y’ (new hole size) = 80-85% of exhaust port.

Or

Simply make ‘Y’ (new hole size) = 80-85% of exhaust port.

Or did I just miss that part somewhere... in the backwoods of me skull.

Cheers!


----------



## rayIN

The _total_ outlet size (new and old hole) should be 80-85% of the exhaust port outlet.


----------



## weimedog

I hacked a couple this weekend..it was windy and rainy out. The first was a bent up and broken Muffler from a Jonsereds 820. I had to split it and fill in holes & removed the baffles. Did these with brazing rod. Curious if it will stand up. The second is a spare muffler I had for my 455 Husqvarna....I haven't run the 455 yet but the 820 really perked up with its new old muffler!

Jonsereds 820:












[/QUOTE]


Husqvarna 455 Rancher:












Think this will work? One thing of interest is the cross sectional area of the 455's exhaust was about the same as the much larger 820! Thats why I used the same diameter exit pipe. Wonder if the X-torq design is part of the reason why the Husky's is so large.


----------



## avason

*Will I gain power with these saws?*

Very impressive gentlemen! I have been itching to try a muffler mod for a while now. Now that I have read this thread I think I am ready to play. I have some saws to experiment on. 
All this epa stuff does have me a bit confused. I have a husqvarna 353 that is an etech model, (I don't know what that means) would I gain anything from modifying this 353?
I also have a husqvarna 36, 51, and a 357xp. Which one would I gain the most out of? I am ready to take this head on and just want to make sure that the model I'm working on is worth working on. 
I just want to say thank you in advanced for your expertise. It has been very educational reading this thread. Keep Modding!


----------



## Adam_MA

I personally can't speak for any of the saws listed other than the 36. I had one of the muffler bolts fall out of my 36. On the 36 that in effect made an extra exhaust port. I noticed right away that it woke the saw up. The down side of this, is that with that saw, a lose muffler caused exhaust gas to melt through the oil tank. So that was of course bad, but just that little extra hole made a pretty big difference. Now that the saw has been repaired, I plan on adding an extra port to get the extra power back.


----------



## avason

Adam A..thanks for the info. That is exactly what I wanted to hear. That was the one that I wanted to experiment with first because it is my smaller saw. Did you have to adjust the the h or l on the saw? Thanks again!


----------



## Adam_MA

avason said:


> Adam A..thanks for the info. That is exactly what I wanted to hear. That was the one that I wanted to experiment with first because it is my smaller saw. Did you have to adjust the the h or l on the saw? Thanks again!



Any saw that you mess with the exhaust or intake you will have to retune the carb. Truly not a big deal, no limiter caps on the 36 so it's easy, and it only takes small adjustments.


----------



## avason

Adam_MA said:


> Any saw that you mess with the exhaust or intake you will have to retune the carb. Truly not a big deal, no limiter caps on the 36 so it's easy, and it only takes small adjustments.



Excellent..thanks!


----------



## freeweight

any way of doing this without welding


----------



## scottr

freeweight said:


> any way of doing this without welding



What saw/muffler ?


----------



## freeweight

if i do this on my husqy's ill get someone that knows how to weld,but i would like to play around with a "powerhorse" from northern tool & equip.  one is 40cc and the other is 50cc i think ,just bought em cause i wouldnt care what happened to them .....but they have NO power whatsoever its really sad seen electric chainsaws do better than these


----------



## RacerX

Anyone ever mod a 020T/200T, or is it not worth the effort on such a small saw?


----------



## automaticman

*Echo CS 400 Mid*

I'm looking at a Echo CS 400. Has anyone done a muffler mod on one of these? Any info wood help. Thanks , Phil:greenchainsaw:


----------



## K.C.

I''l be the first to admit I have not read every post in this thread, but in the ones I have read here as well as the posts in Lakes muffler mod thread I have not seen mention of opening up where the muffler meets the cylinder. 

I just pulled apart my new-to-me 046 and found that while the metal gasket matched well to the size of the port, the heat shield and muffler itself (all OEM stuff) were notably smaller in size so I bolted those parts together and opened everything up to match the opening of the gasket as the first step in my 046 muffler mod. I think that will help a bunch on its own.

I have another idea for the main mod that I will post here if I am successful!


----------



## voxac30dude

Oldbustedsaws said:


> I call it the "Monster" mod cause it reminds me of the monster energy drink logo  Runs like a top!



WTF is this??? you copied my idea! haha. nah it'a all good. glad you admire me


----------



## voxac30dude

Oldbustedsaws said:


> I call it the "Monster" mod cause it reminds me of the monster energy drink logo  Runs like a top!



WTF is this??? you copied my idea! haha. nah it's all good. glad you admire me


----------



## rinkrat311

here's a poulan 4218avx muffler mod....

more detail in my other thread about this "poulan 4218avx build" but thought i would show the pic here also


----------



## sunfish

Husky OE 346xp muff mod. Does this look like it'll work? 1/2" hole under deflecter.
I'll put a screen in it soon.

Ran it a little this morning, cut 10" sycamore like butter. This saw has always run very strong though, so hard to tell if this helped. Need to tune the carb and really put it to work


----------



## avason

sunfish said:


> Husky OE 346xp muff mod. Does this look like it'll work? 1/2" hole under deflecter.
> I'll put a screen in it soon.
> 
> Ran it a little this morning, cut 10" sycamore like butter. This saw has always run very strong though, so hard to tell if this helped. Need to tune the carb and really put it to work



I like how you did that..no welding required! She must sound a lot different. That's a great saw even without a mod...you must notice a difference!


----------



## Tiger Rag

sunfish said:


> Husky OE 346xp muff mod. Does this look like it'll work? 1/2" hole under deflecter.
> I'll put a screen in it soon.
> 
> Ran it a little this morning, cut 10" sycamore like butter. This saw has always run very strong though, so hard to tell if this helped. Need to tune the carb and really put it to work



Looks fine to me, as long as it runs good after carb adjustment. The only thing I see missing is a spark arrestor screen.


----------



## sunfish

avason said:


> I like how you did that..no welding required! She must sound a lot different. That's a great saw even without a mod...you must notice a difference!



Thanks , I've seen the factory deflectors used in this manner with screws. So figured I could make a deflector and do same. Yes, sounds different. I guess I did notice a difference, it cut like a screaming banshee


----------



## sunfish

Tiger Rag said:


> Looks fine to me, as long as it runs good after carb adjustment. The only thing I see missing is a spark arrestor screen.


Thanks! I made it like this so I could add a screen, will get, or make one soon.


----------



## Tiger Rag

sunfish said:


> Thanks! I made it like this so I could add a screen, will get, or make one soon.



I know one of the professional saw builders on here builds his saws with a similar muffler mod. He buys the OEM Husky parts from Bailey's I believe to do his. Not sure if he uses a thread lock compound or not. Not sure how that would hold up to the heat.


----------



## sunfish

Tiger Rag said:


> I know one of the professional saw builders on here builds his saws with a similar muffler mod. He buys the OEM Husky parts from Bailey's I believe to do his. Not sure if he uses a thread lock compound or not. Not sure how that would hold up to the heat.



Belive it's Brad the porting king using this method. Seems the heat would void the thread locker. If I have trouble I'll try it, or lock washers.


----------



## WagonRanch

*XP371 Mod or not?*

After reading this thread I got all fired up and rushed out to do this to my Husky 371XP. Took it apart and was thinking about whether or not to do a pipe or just a screen that's held on by the bracket. 

Well, I got to looking at it and the muff is empty....just a tin can. The exhaust is out the top of the can and has a screen that can be changed, but that's all. The opening is huge....well, maybe not huge, but easily 85% the size of the stock exhaust port, probably more according to my micrometer eyeball. So I just slapped the whole kit and caboodle back together. 

Is there much, if anything, to be gained on this pre-EPA saw by carving up the muff? I'm ready to do it, if somebody can demonstrate that this model benefits from a muffendectomy. The saw runs great and has for years, so maybe leaving well enough alone might be the ticket.

Comments please!


----------



## spiffy1

If that's the case, I don't see it benefitting enough. 

On a tangent to another thread I saw, my dealer noted the 362 coming out a second [of perhaps 20seconds average] ahead of a [somewhat different than here] muff-modded 361, but was quite impressed (didn't test it in wood) with mine done as shown previously in this thread.

Further tangent:  to my dealer who noted "cool muffler mod!" when I asked him to tach it [which he did free - after which I spent $100+ on chains and wedges] to confirm my ear tuning [a bit rich] a while after I did the mod in this thread.


----------



## Jbevs

MnSam said:


> Just did a muffler mod to my 029 this afternoon, can take a few pics and put them up for you if you think it would help. It was fairly simple, and didn't take too long (no welding involved). It is definitely more peppy.



I'd really like to know what size holes you drilled, or how much you opened up the muffler. Also, did you mess with the baffles inside which redirect the flow right after the exhuast port?


----------



## Canyon Angler

I'm thinking of doing Lakeside53's famous 361 muffler mod on mine.

I'm thinking of tigging (braze welding) it with silicon bronze filler. Is there any problem(s) I should look out for with that?


----------



## constantine

I've never done TIG welding, but you just have to be careful that the temp doesn't get too high. The muffler casing is pretty thin (about 0.080") so you don't want to damage it. The oxy-fuel (propylene) torch I used on mine worked great.


----------



## CUCV

Silicon Bronze works great, some of the muffler mods I have done are on .025" metal and I have used silicon bronze and regular steel filler. Its all in the weld prep if there is any rust.



Canyon Angler said:


> I'm thinking of doing Lakeside53's famous 361 muffler mod on mine.
> 
> I'm thinking of tigging (braze welding) it with silicon bronze filler. Is there any problem(s) I should look out for with that?


----------



## dancan

The mig welder worker fine for me , not the prettiest but trees don't have eyes .


----------



## CUCV

Its amazing how good a grinder can make a boogered mig weld look I've done some nice muffler mods with the mig with very little grinding.


dancan said:


> The mig welder worker fine for me , not the prettiest but trees don't have eyes .


----------



## wyk

You guys and your purdy muffler mods. Y'all have slammed Honda civic's, too? 

Here's my quick-n-easy dremel + Scrench mufmod:


















Yes, I do a mouse check before I fire her up. Come fire season I'll prolly put a Husky cover over it and screen it.


----------



## GASoline71

Get caught in the woods around here with out a spark screen... and you'll not be a happy camper. That is why Andy went to the trouble of making one that would accept the spark screen off a TS400 cutoff saw.

Anybody can hack a hole in a muffler and pry it open with a scrench... what the heck, do you drive a Passat? 

Gary


----------



## Tzed250

GASoline71 said:


> Get caught in the woods around here with out a spark screen... and you'll not be a happy camper. That is why Andy went to the trouble of making one that would accept the spark screen off a TS400 cutoff saw.
> 
> Anybody can hack a hole in a muffler and pry it open with a scrench... what the heck, do you drive a Passat?
> 
> Gary





LOL!!!! ....that'll leave a mark!!!!

.


----------



## wyk

GASoline71 said:


> Get caught in the woods around here with out a spark screen... and you'll not be a happy camper. That is why Andy went to the trouble of making one that would accept the spark screen off a TS400 cutoff saw.
> 
> Anybody can hack a hole in a muffler and pry it open with a scrench... what the heck, do you drive a Passat?
> 
> Gary



Ouch! 

Well, in my defense, that is my GF's Jetta diesel. You see her at the end of my last vid. I drive a Comanche(mj), a Chevy Colorado, a TJ and a Chevy 3500. The Jetta is in the barn because the CV's blew up ;( The manche gets the wood out of the forest, the 3500 takes it to wherever or whomever needs it when we have enough(which seems like never with our hungry furnace), and the rado mostly takes me on pavement. The Tj mostly tries to kill me.

As for fire marshals, who do you think sold me his saw?  Outside of fire season, the others don't care.

Here's the poor lil Jetta after it threw it's CV out in Tigard:







I really shouldn't make fun of you guys, coz the girl also has a slammed Scirocco. Or however ya spell it. She's from Belgium, go figure.

WYK


----------



## ncvarmint

Hello, 
I have a ms361 that i want to mod the muffler like Lakeside53. But i had some questions on what stuff he or you all used
1) Did you use mapp gas to braze ? AS i have some in the basement)
2) What kind of brazing rod did you use. 
3)Any good place to buy a 5/8od, 9/16 Id pipe (what kind of pipe do you recommend)
4) Can i drill a hole in the muffler with a regular drill bit and not have to drill it on a angle, to put the pipe in once i cut a 45 degree angle?

BTW Does Lakeside53 sell the kit (pre finished pipe, spark arrester, clip), if so how much, or how much if i bought a muffler and sent it to him. 
I tried to pm him but him box was full

thanks so much for any and all help

trevor


----------



## Trigger-Time

ncvarmint said:


> Hello,
> I have a ms361 that i want to mod the muffler like Lakeside53. But i had some questions on what stuff he or you all used
> 1) Did you use mapp gas to braze ? AS i have some in the basement)
> 2) What kind of brazing rod did you use.
> 3)Any good place to buy a 5/8od, 9/16 Id pipe (what kind of pipe do you recommend)
> 4) Can i drill a hole in the muffler with a regular drill bit and not have to drill it on a angle, to put the pipe in once i cut a 45 degree angle?
> 
> BTW Does Lakeside53 sell the kit (pre finished pipe, spark arrester, clip), if so how much, or how much if i bought a muffler and sent it to him.
> I tried to pm him but him box was full
> 
> thanks so much for any and all help
> 
> trevor




Lakeside53 retired from AS some time back and we lost one of the best!




TT


----------



## ncvarmint

Trigger-Time said:


> Lakeside53 retired from AS some time back and we lost one of the best!
> 
> 
> 
> 
> TT



that sucks, 
maybe the other here will be happy to help. :biggrinbounce2:

trevor


----------



## southbound

wyk said:


> You guys and your purdy muffler mods. Y'all have slammed Honda civic's, too?
> 
> Here's my quick-n-easy dremel + Scrench mufmod:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Yes, I do a mouse check before I fire her up. Come fire season I'll prolly put a Husky cover over it and screen it.





Does that let any heat/fumes on you hand or in you face????


----------



## Trigger-Time

ncvarmint said:


> that sucks,
> maybe the other here will be happy to help. :biggrinbounce2:
> 
> trevor




Yes it does! and am sure they will 



TT


----------



## JJay03

Did anyone ever find a good place to get the 16mm tube from? I tried my local true value and they did not have it. 

Its funny how little some stihl dealers know also trying to tell me it will hurt my saws performance lol. They did not even know what the RMC chain was.


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## ScottWojo

JJay03 said:


> Did anyone ever find a good place to get the 16mm tube from? I tried my local true value and they did not have it.
> 
> Its funny how little some stihl dealers know also trying to tell me it will hurt my saws performance lol. They did not even know what the RMC chain was.



Jay, no disrespect to andy...but are you certain you want that condom looking screen with that hose clamp on your saw? I just think it looks cheesy, even on the blowers.

It does not have to be exactly 16 mm. I make my mufflers much larger than the small pipe Andy used. And the saw screams.

If you can just go to your local scrap yard and ask to see their steel pile. Chances are good you will be able to find something with a pipe on it that will be the right size.

Thanks,
Scott.


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## JJay03

I was just looking for the 16mm cause I alrdy have the screen and clip. I think it looks pretty good when all done. I also thought about buying the husky parts but I alrdy have these parts in hand and that would be more money plus shipping.


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## ScottWojo

PM me your address and I will send you the part you can weld in. no charge. I will pay for shipping.

Scott


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## dancan

JJay03 said:


> Did anyone ever find a good place to get the 16mm tube from? I tried my local true value and they did not have it.


 


ScottWojo said:


> PM me your address and I will send you the part you can weld in. no charge. I will pay for shipping.
> 
> Scott


 
That's a great offer from ScottWojo ! 
Sure beats running around looking for stuff !

I used caliper slides for mine , the od was fine for the screen but I had to run a drill through it for the id .
The slide I used had a groove on the ends to hold rubber dust boots so when I cut the tube to fit I used the groove to hold the clamp , one tube did 2 mufflers .
The next ones I do may just get the Husky screen and deflector .


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## JJay03

Thanks again! Sent you a PM.

The caliper slides were a good idea also dancan.


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## ScottWojo

dancan said:


> one tube did 2 mufflers .
> The next ones I do may just get the Husky screen and deflector .


 
But you just cant beat that sound that comes from a pipe.

Part is on its way, should have it Wednesday. 


Scott.


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## Slackerjpt

OH MY :msp_confused:


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## ScottWojo

Slackerjpt said:


> OH MY :msp_confused:



Yeah me too.


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## docrw

*Husqvarna 61 muffler mod (positive results)*

I just did my Husqvarna 61 a few days ago and the difference was remarkable! I was so impressed and it was more noticeable than my two Jonsered 625II muffler mods! :wink2: I did a small vent on the oposite side with (5) 3/8" on the plate.



SRT-Tech said:


> would it be worthwhile doing a mod on my Husky 61 muffler? Its a 2 piece, with removable baffle plate/screen.


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## Bowtie

I have done a lot of the Lakeside 361 mods. he actually was sending people to me before he got sick of the rigamorole here and retired.

Its dead easy. I use 1/2" or 9/16" ID pipe and the TS400 screen and clamp. I use a tiny tip on an oxy acetylene torch and braze it on. I aint gonna dig up my pics, but they are on here. Its not hard to do. Just remember to retune the carb properly.


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## SawTroll

The muffler on my Euro MS361 is an Andy one (done by him), but made a bit different, as I don't need spark screens over here! The tube is at the upper right corner of the muffler, not down left.

It works great! :msp_smile:


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## kmcinms

docrw said:


> I just did my Husqvarna 61 a few days ago and the difference was remarkable! I was so impressed and it was more noticeable than my two Jonsered 625II muffler mods! :wink2: I did a small vent on the oposite side with (5) 3/8" on the plate.



I need to do something similar to the muffin on my 61. Did you do any port work to the saw? Here is the one I rebuilt last year. Piston and cylinder was perfect, replaced the ring and left the base gasket off. Did a 70% exhaust port on it. Runs well :msp_sneaky:

http://www.arboristsite.com/chainsaw/99507-42.htm#post2839914


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## saxman

Here is my 361 muffler I did back in the day. Really helped the saw. I did the same type of mod on my old 441, I have a new M-Tronic now and not touched it yet 


Steve


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## docrw

*Husqvarna 61 muffler mod and porting*

I haven't done any porting yet (time) but I want to. I saw your work and it looks nice, I'd like to do the same clean up to all the ports, maybe you could expound on what you did any port width numbers and performance difference. BTW I used a vent I ordered from parts tree and it fits perfect where I put it. I bought this saw off craigslist because it was so so clean but noticed it has some scoring on the piston which I'm hoping to clean up, since I won't spend $80. for a new piston...



kmcinms said:


> I need to do something similar to the muffin on my 61. Did you do any port work to the saw? Here is the one I rebuilt last year. Piston and cylinder was perfect, replaced the ring and left the base gasket off. Did a 70% exhaust port on it. Runs well :msp_sneaky:
> 
> http://www.arboristsite.com/chainsaw/99507-42.htm#post2839914


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## FlyLow

wyk said:


> You guys and your purdy muffler mods. Y'all have slammed Honda civic's, too?



Yup....:msp_wink:






Not my house

AMG E55 470hp 0-60 3.9 sec


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## tthstrm179

*Thanks for the info! Here are my results.*



Lakeside53 said:


> Continuing from the earlier post in this thread showing the inside of the 361 muffler and spark arrester issues.
> 
> 
> The easiest solution to adding a port is simple to drill a hole and insert a tube. Covering this with a screen is a poor choice as the surface area of the screen is small. Stihl solved this problem on the BR400/420/340/380 series of blowers (as far back as 1992 on the BR 400) by inserting a tube of screen material into the pipe. It folds back over the pipe and is secured by a clip. The screen is many times the area of the outlet, so flow restriction even with some blockage is minimal.
> 
> This can be used on any almost any saw where you need a spark arrester and are adding a port (so long as you have room inside). You can of course choose not to fit it, but so long as the tube is the correct dimension, you have the option of putting it back in!
> 
> 
> 
> 
> 
> 
> There are two basic sizes available: One fits over a 14mm OD (roughly 1/2 inch ID) pipe and the othe over a 16mm OD thin wall pipe. The picture shows the 14mm version. I'll have the 16mm version is a day or so and will likely use this as the pipe is thin wall 9/16 ID tube will work and is easier to find (for me).
> 
> Part numbers:
> 
> 14mm version (BR420 etc blower)
> Screen - 4203 141 9005 $5.56
> Clip - 4203 141 6600 $2.00
> 
> 16mm version (TS 400 Cut-off saw)
> Screen - 4223 141 9000 $4.25
> Clip - 4223 141 6600 $3.25
> 
> 
> I did not need to tear the muffler apart to do this modification. The only reason I did was to educate myself on the internals and space constraints. In the future, it's just drill a hole at 45 degrees, grind the bottom of a short tube at 45 (so the screen has maximum area inside the muffer), and braze it on. For those of you intimidated by the thought of brazing, it is dead easy and can be done with Mapp gas available at your local hardware store.
> 
> The easiest way to drill a big hole at 45 degrees in thin metal is to use a uni-bit or one of the cheaper clones. They look like this :
> 
> 
> 
> 
> 
> 
> 
> Here's the muffler back together (heated the crimp area "red" and crimped it back together):
> 
> 
> 
> 
> 
> 
> 
> This is what the 14mm screen looks like inside the muffler. The 16mm is longer.
> 
> 
> 
> 
> 
> 
> 
> Here's the completed muffler on the saw. The factory spark arrester and exhaust port are unmodified. Heck you could even put it back to "factory" by plugging the new port!
> 
> One nice coat of matt exhaust paint and a quick bake (450F for an hour in the convection oven!) and it's one tough coating and ready for work. Hmmm, looks like factory stock to me.
> 
> 
> 
> 
> 
> 
> 
> 
> Questions? Improvements?



I know this post is several years old, but based on the number of people who have viewed it, it seems still popular. I thought I'd post my results of following Lakewood's procedure. 
I picked up a 1/2" ID piece of steel pipe from the hardware store. It was thick walled and in the trays of misc. nuts and bolts. The steel was sold as a steel spacer, was 1" long and cost $1.80. 

I had the local shop weld the metal on after I cut it at a 45 degree angle. Rather than drilling the hole in the exhaust first, I drilled it after the welding to reduce the chance of melting through. The welding cost me $20.00.
View attachment 222107



I ordered the smaller of the two spark screens which cost me about $6.00, and then picked up the clip from the hardware store for $.80. Due to the thick wall of the steel spacer I had to slightly slit the screen on the outside to make it fit over the outside.

Altogether this mod cost me less than $30.00. A coat of high temp paint and it was done. 

View attachment 222108


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## garzanium

Greatest thread ever. Worked on my 361 today.

I didn't find the info on muffler removal for the 361..so wanted to add it.

If your muffler has the 2 little rivets in the front,you will have to remove them with a screwdriver to access the torx screws. You will need:


-#27 torx
All you need to do is remove the 2 torx and bottom torx screw bolts and the muffler come straight out.
I was concerned about MIG welding black steel to the muffler, but it worked great.soldering didn't work for me.


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## Eoghan

*338 xpt mod*

Hey Guys, just finished up on the 338xpt and 460 mods. Port matched the exhaust port>gasket<to Muffler. Enlareged the mufler output to 1/2'' and smoothed out all edges. Welded an Eyelid over the output to direct the gases away from my hands ( FINALLY). Then Pulled the limiters and and tuned it up! Now it should be called the 338 screamingeaglePT. Wowza what a difference. Ran through some 8" spruce alot faster and more consistent. Alot less Lobing and slightly higher rpm. Havent fully finished the mods to the 460 yet, but I can only hope its a similar outcome. Have a pic of the 338 muffler, still a bit rough, but I'll clean it up and paint it tomorrow!

Oh and exhaust temps dropped 42degrees !!!

View attachment 279383


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## ScottWojo

Eoghan said:


> Hey Guys, just finished up on the 338xpt and 460 mods. Port matched the exhaust port>gasket<to Muffler. Enlareged the mufler output to 1/2'' and smoothed out all edges. Welded an Eyelid over the output to direct the gases away from my hands ( FINALLY). Then Pulled the limiters and and tuned it up! Now it should be called the 338 screamingeaglePT. Wowza what a difference. Ran through some 8" spruce alot faster and more consistent. Alot less Lobing and slightly higher rpm. Havent fully finished the mods to the 460 yet, but I can only hope its a similar outcome. Have a pic of the 338 muffler, still a bit rough, but I'll clean it up and paint it tomorrow!
> 
> Oh and exhaust temps dropped 42degrees !!!
> 
> View attachment 279383



Nice job. How are you measuring temps? and Celsius?


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## Eoghan

Infrared thermometer ! and yes in Celcius. I operate at 3500 ft+ daily so rich conditions are easy to miss. So I've been checking exhaust temps on every job with a consistent drop in temps overall! This should give some extra life to the P&C while getting every bit of power from these lightweights.


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## Eoghan

Eoghan said:


> Infrared thermometer ! and yes in Celcius. I operate at 3500 ft+ daily so rich conditions are easy to miss. So I've been checking exhaust temps on every job with a consistent drop in temps overall! This should give some extra life to the P&C while getting every bit of power from these lightweights.



Hey Does anyone else lose half of what is written on here?? My posts are getting shortend severly.......


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## Fish

Andy WHO??????


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## spladle160

I thought I would share some pics of my 36 MM. I am a process piping project manager so I had one of the guys tig weld this .020 wall 5/8 304SS on there.
The paint is VHT flame proof. It doesn't really match as well as I'd hoped.
View attachment 286799
View attachment 286800
View attachment 286801
View attachment 286802
View attachment 286803


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## NewBee-CRO

Hi all .. This is the exhaust from my Stihl 026 muffler wanted to make a mod so I need help ..
How best to do that and to be cautious of sparks ??

I was thinking to drill a hole in the center?
How to make the output part of the muffler?

Does someone have a picture ??

Thank you all


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## blsnelling

It would be best to start a new thread and keep this one about the 361. Or there are probably lots of threads/posts on 026 muffler mods. However, I've never seen an 026 muffler like yours. I'd start a new thread to discuss it.


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## splitpost

blsnelling said:


> It would be best to start a new thread and keep this one about the 361. Or there are probably lots of threads/posts on 026 muffler mods. However, I've never seen an 026 muffler like yours. I'd start a new thread to discuss it.


i got one just like it Brad ,its aftermarket

Sent from my GT-S7500T using Tapatalk 2


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## Bieber

bsnelling said:


> It would be best to start a new thread and keep this one about the 361. Or there are probably lots of threads/posts on 026 muffler mods. However, I've never seen an 026 muffler like yours. I'd start a new thread to discuss it.


Not 100% sure but I think this is an oem Stihl European muffler.


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## xanik

Bieber said:


> Not 100% sure but I think this is an oem Stihl European muffler.


 Yes you are right. Its the European version of the 260 muffler


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## HarleyT

Hairy armpits?


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## saxman

You new members really missed out on a great guy in Lakeside Andy. He was a wealth of knowledge and always had time to help. I really enjoyed his posts and did a Lakside mod on my 361’s muffler many years ago. I was just running it this afternoon, great saw!


Sent from my iPhone using Tapatalk


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