261CM Gen II muffler mod questions

[HotRail]

I did a search on the site for this topic and it came back with HolmenTree's post about taking out the spark screen....real simple so went ahead and did this.  Yes a little louder and maybe seems a little stronger. My question to HolmenTree or any others is how big a mod is required to make it worthwhile w/o being ear splitting loud... I realize they kinda go hand and hand but what would be the minimum expansion of the existing muffler outlet without doing any gills or taking apart the muffler and recrimping.  I basically want to expand the existing exhaust hole and staying within the built in deflector.  I do realize if I do any cutting or grinding on the muffler I need to take it off the saw and be darn sure no shavings or steel is left inside.  Btw I have a 2017 Gen II 261cm that has been absolutely trouble free and I am very happy with.  I have owned a Gen I 261 carb model with muffler mod, a ported Gen 1 261cm, and now the Gen II stock form. Its warranty just expired I believe or close to it so no worries there.  It is well broken in but not even close to being used everyday or anything like that.  I put a 16" stihl ES guide bar and 3/8" RS chain on it recently and boy does it work surprisingly well.  I personally like the balance better now also.  I owe that to HolmenTree cause I kind of gave up on the idea of 3/8" chain in hardwoods for the 261cm until I was reading his posts.

Thanks
BK

[HotRail]

Ok, not many ideas for the muffler around here looks like, thats ok. I was planning for not to mess with this 261cm but lol.  The 2 saws that were modded were done by the guys doing it for a business.  They did an excellent job btw
...maybe I'll just leave it as is.

[lxskllr]

Since you aren't getting much love, you got me! What's in the muffler? My 362cm is pretty much an empty can, and about as loud as I want it. I took the spark arrestor out, but I don't think there's much left without going to something exotic.

[HotRail]

Since you aren't getting much love, you got me! What's in the muffler? My 362cm is pretty much an empty can, and about as loud as I want it. I took the spark arrestor out, but I don't think there's much left without going to something exotic.

Alright, thanks for the response....from what I can see on my 261cm muffler from the exhaust outlet hole it looks like there is some baffling in these mufflers....not for certain though, I could very well be wrong.  Anyways, I'm gonna leave the spark arrestor out and call it good.

[HolmenTree]

HotRail,
It's best to just enlarge the existing exhaust outlet rather then adding another outlet.
Like said the 261 muffler is just a empty can.
There is a ledge that holds the screen in place on the inside of the outlet that adds restriction.
You can enlarge the outlet all you want but the ledge also needs to be enlarged.
Then the screen needs to be screwed over the outlet on the outside of the muffler wedged under the deflector. Don't go overboard in outlet size .
I did a rough job with a dremil as I had to work under the deflector but got it done as the mod does the job for a work saw.
Screens are a must from seeing fires started in some of the logging camps I worked at.
One of the crews lost half of their weeks production when they came to work monday morning and found half of their pile in the landing burnt up over the weekend. 

[HotRail]

Thanks HolmenTree and lxslr....ok, yes what I was thinking of "baffling" on the inside is this ledge that HolmenTree is talking about...anyways I do like the sound of the saw just without the spark screen fwiw, but do not want an overly obnoxious saw for a work saw.  Thanks again.

[HotRail]

Holmen Tree or lsxkklr - would a guy need to put a new gasket on when you remove the muffler ??  Im thinking it should be fine but not sure.  Thanks

[lxskllr]

I've saved the gasket. If you can get it off without damage, it should be fine.

[HotRail]

Thanks for the reply...sounds good lsxrllr

[HotRail]

Well, drilled a 7/16" hole next to the existing one on the muffler where the spark screen bolted in....sounds good and mean but not too abusive lol...anyways lsxllkr or HolmenTree what have you used for a new spark screen??  

[lxskllr]

I haven't used anything, but most times you'd need a cup of diesel to set things on fire here. If you have a potential fire hazard, you should probably have something in place. Maybe find a bigger screen and cut it to fit. You may also be able to add another standard arrestor next to the stock location.

[Two Trax]

This is how I modded mine. Seems to have made a difference and not too loud although I wear ear protection anyway. Used a dremel and screwdriver.  Was able to reuse stock gasket.

[HotRail]

I'm not one to do the timed cuts or stuff like this but I'm of the opinion that opening up the muffler on most any saw will give you more in the cut rpms or torque.  Anyways, I like the sound of the 261 better, not too loud, and I "think" it powered up a little for sure.