Stihl 044 - Suggested Muffler Mods?

[SteveSr]

Hello,

I have a new to me Stihl 044 that has the EPA muffler with the 10mm hole (1128-140-0604) instead of the previous with the 18mm hole (1128-140-0607). It appears that the EPA mods raised temperatures significantly that they had to also add several heat shields to protect the cylinder and crankcase and maybe the top cover from overheating.

So what is the best way to turn back the clock to non-EPA time? Just enlarge the hole in the existing muffler to an effective 18mm diameter. Is this enough to get a good HP increase or should it be bigger? Suggestions?

Thanks,

Steve

 

[Trx250r180]

@MustangMike

 

[Chainsaw Jim]

You are on the right track. Enlarge the hole and that saw will rip.

 

[blsnelling]

Open up under the deflector all the way to the back, top, and bottom. Do not bring it any farther forward. You'll also need to remove the limiting tabs on the carb needles and re-tune.

 

[Stihlofadeal64]

Or you could put a dual port cover on the muffler. I believe they were running less that $20.00 the last time I checked flea bay.
Make sure to tune the carb as well if you switch the cover.

 

[blsnelling]

Or you could put a dual port cover on the muffler. I believe they were running less that $20.00 the last time I checked flea bay.
Make sure to tune the carb as well if you switch the cover.

You'll want to open up the hole in the main body even if installing a DP cover. You'll gain more area with the larger opening than the DP will give you. Of course, you could always do both

 

[Adirondackstihl]

This is a 461....but same concept.
I also added a DP cover.

Before


After

 

[Adirondackstihl]

 

[Foragefarmer]

If you want a good HP increase you should add an HD2 air filter as well. I added a DP cover to my 10mm 044 and ran it. But then I added a HD2 filter and tached it before and after and the filter added 800 rpms. So you will need to retune after you add the filter as well.

Also on the DP cover the hole in the cover and the spark arrestor screen cover didn't match well on my after market cover so I ground the exit hole to match.

 

[mcobb2]

This is a 461....but same concept.
I also added a DP cover.

Before


After

What a hack... GFY

 

[SAWMIKAZE]

Id skip this whole muffler mod thing and just send it straight to tennessee for a new recipe if it were mine.

 

[Trx250r180]

Just put your bar wrench in the slot in front of the round exhaust port and twist ,instant dual port

 

[SteveSr]

Open up under the deflector all the way to the back, top, and bottom. Do not bring it any farther forward. You'll also need to remove the limiting tabs on the carb needles and re-tune.

Thanks, i was looking for pictures of the old muffler but couldn't find any. This answered the question prefectly. Looks like this would be best done from the inside with a Dremel or equivalent. Operating from the outside looks kind of tight with the deflector on it.

 

[SteveSr]

What a hack... GFY

Looks like nice machining to me! What tools did you use?

If that is a 460 muffler it looks like the deflector is wider and shallower than on my 044 which may make machining from the outside a little more challenging...

 

[big t double]

What a hack... GFY

now you have photographic proof...you don't have to warranty his crap now

 

[pioneerguy600]

A 3/4" or 19mm hole works really good for a non ported 044, once they are ported you need more, a dual port works better then.

 

[windthrown]

As Stihlofadeal64 says above, just put a DP muffler cover on it. AdirondackStihl has a photo posted of it. No tooling or drilling to other BS required. Simple job, takes 15 minutes.

I put a Canadian 460 DP muffler cover on my 044 and re-tuned the carb and insto-presto upgraded saw. More power than a stock 460, lighter and less vibration. No shipping to Tennessee needed (or waiting in a 3 month long queue). Ran cooler, ran better, stress was within the original design specs of the saw. Also quitter than drilling holes bigger and way cheaper than getting it ported.

 

[RedneckChainsawRepair]

If you have a cage in the back half, remove it or drill it open big time IMO

These didnt need any modding as I just replaced with after market complete DP mufflers for $25 apiece shipped. Made by Raisin. 460 and 440

 

[ktoom]

Ive thought about "fish gilling" my stock 044 muffler cover. Anyone ever tried it???

Whats the p/n for the oem Stihl DP cover?

 

[big t double]

1128 140 0801