Lakeside53's --361 muffler mod w/photos

[(WLL)]

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]

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]

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]

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]

Looks good, nice work!!!

Thanks.

 

[SLlandscape]

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.

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.

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