Husky 359 Power Increase

[Bills Oak]

For all of the Husky Experts out there. What is the easiest way to get a little more power out of my 359 saw without going into major mods. I'm using a 20 inch bar & saw works just fine just wondering about easy mods to do.--Thanks, Bill Irvine

 

[rbtree]

Open the muffler. Here's my brand spanking new 357 done by Ed Heard. it has been fully modded, and is one amazing screamer! If you look closely, you'll see where he installed the second port. It looks to be 1/2 inch by 11/16 oval. The goal is to make the total port size equal to 1 to 1.25 times the size of the cylinder exhaust port. Also check to make sure the gasket and ports all line up. Muffler mods alone should gain you 15-20% in power, if not a tad more. You'll need to tune the carb for optimum rpm and cutting speed, which means richening the jets as required.

 

[jokers]

Schweet saw Rog!


Bill,

Roger gave you the straight scoop on the best bang for your buck, just remember to start at about a 1:1 cylinder port to muffler opening and work your way larger if need be. It`s a PITA to put back what you shouldn`t have taken out, LOL.

Russ

I`ve found since the time that I posted this info that about 75% of the exhaust port size is a good place to start when modifying a muffler on a stock saw. Thanks ehp!

 

[NebClimber]

I just bought a new Husqvarna 357 XP. The thing has no power. My tophandle echo honestly seems to go thru wood better.

So exactly how do I "open up the muffler"? I'm not a mechanic. In fact, I'm pretty helpless when it comes to this stuff, but I really need this saw to do a better job.

So again, exactly what do I do to "open up the muffler."

Any help would be greatly appreciated.

Steven

 

[jokers]

NebClimber,

Maybe you should send your gutless 357xp to me! LOL.

Do a search here for muffler mods on the 357 and you will find examples.

Russ

 

[Dr. Hackemoff]

Nice looking lawn in that picture. Do you bag or recycle?

 

[dozerdan]

NebClimber
Here is a picture of the extra muffler outlet. Its a 372 but you will get the idea.
There is also an internal baffle plate of the 357 muffler that will have to be removed.
Later
Dan

 

[Hunter]

RBTREE,
I take it you like the EHP357xp. I figured you would like it. I have one its also a powerhouse. What length bar are you running and how many hours do you have on it?
Thanks
Hunter

 

[Doug01]

Bill,

I just did a 372. It is sort of like the pic that Dan posted but it is round. I started out with a 5/8" hole but moved it up to 3/4" by other recomendations from someone at this site. I did a round hole because all I did was drill...didn't have to cut. If you do it this way, get a unibit if you don't have one. It makes a perfect hole. The standard drill bit made the hole a little "out of round". I don't know what to tell you about the baffle though.

Doug

 

[Lawn Masters]

For detailed instructions on opening up your muffler, I can give them to you.

You start by removing the muffler from the saw to prevent any metal shavings/dust from the drilling/cutting from getting into the cylinder and damaging the piston and cylinder.

After you remove the muffler, you separate the 2 halves of it, remove pretty much anything you see inside, if its loose, it goes, if its fastened in, cut it off. Do this to most anything, other than the sides of the muffler itself.

Next, you get your dremel/drill, either one is fine, and you cut or drill a hole in the front of your muffler cover, this will reduce restriction of exhaust gases as they are leaving the saw, allowing it to run significantly cooler thus prolonging the life of the saw. You can start with a dremel to cut a hole or drill one with a drill and make it to the appropriate size and then take an air hose and blow all metal shavings out of the muffler so they dont get sucked back in when you start the saw the next time.

Then put the muffler back together, just throw the ballfes and anything you removed from it in a box/garbage can, and put the newly gutted muffler halves together and re attach it to the saw, then get out your earplugs and a sharp chain, you'll LOVE the power of your saw after the modifications are done.
Dont forget to adjust the fuel mixture on the H and L screws to a richer setting as this will prevent lean seizure in your valuable saw and save you money by not destroying the piston and cylinder.

Then take your saw outside and enjoy!

There you go, thats how you modify a muffler to gain HP and allow your saw to run cooler. Please feel free to add anything I may have forgotten to mention.

 

[sedanman]

OA this advice is based on the dozens mufflers you've modified? I would not just disembowel the muffler. You can always remove a little more materail, it's a real B1TCH to put any back. Is this more of the mental problem you mentioned on another thread? Or are you merely regurgitating information again?


Here's the quote, remember when you had people looking for equipment you did not intend to buy?

"I'm sorry about that, I make strange decisions on impulses and then I think about them later and realise that I have no idea why I need something in the first place. My place seems to be more to the effect of the woods or at sea, not at a pc. I'm simply trying at least as of right now keep myself from spending money I dont have, again this is caused by a mental disorder that causes me to behave impulsively, I'm trying to get control over this problem as I post this, my next move is to see a medical professional about it. Once again, I'm sorry for the inconvienence that I may have caused anyone." (Oldsaw Addict)

 

[rahtreelimbs]

One thing to make sure of is to deburr anything that you have cut, removed, etc. This is important. Any loose metal can free itself up down the road and wind up inside the engine.

Also, IMO compressed air is good to finish cleaning the muffler. Mufflers that have some run time on them have an oily residue in them that will hold metal shavings. I always wash the muffler out in soapy water first then use compressed air. If there is a lot of residue a propane torch will dry it up and make it easier to remove. The trick is to dry it up before you do any work on the muffler.

 

[046]

First let me put my disclaimer, as I have only modded one muffler.

but I've came up with an inovative way to measure the size of the ports. (maybe you have a better way?)

According to the experts and by no means am I an expert. with one muffer mod under my belt ha ha ha.

Anyways I was scratching my head on how am I going to measure how much material to cut. Let's see the exhaust port is oval and the port I'm adding is round. the internal hole needs to be oblong.

Solution: I used some small round spegetti. Filled the exhaust port up and counted the number of spegetti it took to fill the space. Then I filled up the new exhaust port, then counted the number of spegetti it took to fit. Divide the two numbers and you have a fairly good idea of what the ratio is.

The formula given by the pro's here is to open up your exhaust 1 to 1.25X the exhaust port size.

I elected to copy the walker design for my 335, which is 85% of exhaust port.

The result is it kicks butt. (after adj the carb of course) I'm glad I went with the smaller size hole first.

 

[sedanman]

046, I like your unconventional approach! Very clever.

 

[Marky Mark]

I copeid a walkers when I did a few of them, Then it became easier to have the person who built my saws do it since they are more in tune with these beasts. Now I have a new 066 that I am going to have worked over. I wonder where that one might go. I need another saw like I need another computer.

I will be picking up a few 090's next week when I am down in Uraguay. But those saws are just way to big of a club to have anything done to them.

http://www.arboristsite.com/showthread.php?s=&threadid=5148&highlight=muffler

Rich I think your right about the washing before and after. Time to let the puppies out.

 

[Bill G]

Originally posted by sedanman
OA this advice is based on the dozens mufflers you've modified? .....Is this more of the mental problem you mentioned on another thread? Or are you merely regurgitating information again?


Here's the quote, remember when you had people looking for equipment you did not intend to buy?

"I'm sorry about that, I make strange decisions on impulses and then I think about them later and realise that I have no idea why I need something in the first place. My place seems to be more to the effect of the woods or at sea, not at a pc. I'm simply trying at least as of right now keep myself from spending money I dont have, again this is caused by a mental disorder that causes me to behave impulsively, I'm trying to get control over this problem as I post this, my next move is to see a medical professional about it. Once again, I'm sorry for the inconvienence that
I may have caused anyone." (Oldsaw Addict)

Sedan hit it on the head. By the way OldSaw the 750 you wanted is still available and I believe Brad still has the 075 you wanted. Now for getting back on the topic I cannot offer any advice as I have never modified a muffler. I guess i could copy what other have said but what the he"" good would that do.

Bill

 

[WoodTick007]

Holiday Inn Express

I have never modified a chainsaw muffler before. If anyone wants to send me theirs, I have an 80 gallon 2 stage compressor and a few die grinders that will tear them puppies up.....

PS..... I did stay at a Holiday Inn Express last night. Does that count????

 

[NebClimber]

Next question:

After I open up the muffler, how do I "adjust the carb." Sounds like there is a screw a hi/lo screw I turn. So do I turn it higher or lower. And how high or how low?

steven

 

[sedanman]

The"hi/lo" screw is actually 2 screws. The screws control how much fuel is metered into the air going to the engine. There is one screw that makes this adjustment at low throttle openings (read this as idle) and another that is resposible for high throttle opening (read as full throttle). Idle and wot (wide open throttle) are the only places where we adjust the fuel mixture which is one of the reasons to always cut at full throttle. To be honest, until you have mastered the concept of carburetor adjustment, I cannot recommend that you tinker with your muffler.

 

[sedanman]

I have a friend who grew up in NYC, never mowed a lawn until he was in his 20's. Now he's a genuine redneck!