MS261C -M Muffler Mod ?

[Gypo Logger]

That's exactly how I did my 261 MM. Night and day difference.

I actually changed my method of muff mod after one member pointed out the direction of the exhaust.
So I just elongated the existing port and port matched the gasket with the muffler and cylinder. I haven’t run it yet but will report back later today with results.
And I don’t want to hear any hoof rasp comments from the cheap seats! Lol

 

[Gypo Logger]

A better picture of my fine workmanship.

 

[pioneerguy600]

View attachment 779980 A better picture of my fine workmanship.

How about cold chisels and bfh`s?

 

[Gypo Logger]

How about cold chisels and bfh`s?

I lent those to Al Smith.
I’m sure I got a 20% gain on the muff mod.

 

[pioneerguy600]

You going to replace the deflector?

 

[Gypo Logger]

You going to replace the deflector?

No, I can’t see the point, I just elongated it. I went further on the second saw and ground away the rectangular box that the spark arrestor fits in.
I’ll take a picture.

 

[pioneerguy600]

As long as the hot exhaust gasses don`t melt anything then no need.

 

[Gypo Logger]

The spark arrestor retaining bolt is a good delete because it strips easily.
I wonder it other muff mod maniacs also ground away where the bolt should be?

 

[pioneerguy600]

3/4" diameter hole is all they need.

 

[Gypo Logger]

As long as the hot exhaust gasses don`t melt anything then no need.

Good thought Jerry, the exhaust will interfere with the chain break only if I run the saw with it on.

 

[pioneerguy600]

Don`t melt the handle, they melt easily, that is why I always use a deflector.

 

[pioneerguy600]

You know clicking it on and off with the engine running it will be right in front of the exhaust port. clickers!

 

[MountainHigh]

Once I'm sure my saw is running rock solid, I'll be doing a muff mod but I want/need to retain the spark screen.
Any suggestions on best way to open it up and still only use the spark screen outlet?

 

[pioneerguy600]

Maybe John can help you, I always toss the screens away, no need for them here.

 

[MountainHigh]

Maybe John can help you, I always toss the screens away, no need for them here.

John?

I'll pull my muffler off over the holidays and have a peek at what might work.

Thanks and Merry Christmas.

 

[pioneerguy600]

John?

I'll pull my muffler off over the holidays and have a peek at what might work.

Thanks and Merry Christmas.

Gypo Logger.

 

[split_wood]

noob here. Any more info? Thank you.

 

[EchoRomeoCharlie]

noob here. Any more info? Thank you.

Cut a few slits down the flywheel side of the muffler with a dremel cut off wheel.

Bend the metal out to direct the gasses forward(bar side), if it's an M-tronic saw, re calibrate, and run it.

 

[split_wood]

Cut a few slits down the flywheel side of the muffler with a dremel cut off wheel.

Bend the metal out to direct the gasses forward(bar side), if it's an M-tronic saw, re calibrate, and run it.

I like that will give it a try.

 

[Lenny540]

The 261cm is a great little saw. With a bit of work, you can get some impressive gains simply modifying the muffler.

The 261 is different from most of it's brethren in that it has a baffle plate situated directly between the cylinder exhaust exit and the muffler exhaust exit. It is the ONLY thing in the muffler that prevents the exhaust venting nearly directly from the cylinder in to the world. One. Tiny. Plate. When you remove this, the exhaust now has about an inch of travel before it hits atmo. This does two things - removes and prevents any chance of exhaust reversion - and it makes the exhaust very, very, very loud. The end results are much more power everywhere in the rev range.

This is what the muffler should look like when you remove the baffle(I've also opened the external muffler port a bit) - you should be able to see the cylinder exhaust port directly from the outside of the muffler:

This is the result I get on video - the unmodified 261 first, and then only a muffler mod:

That makes total sense as does the sizing. I've always heard not to go larger than something like 75% of the cylinder exhaust port.

How the heck did you get in there to cut it out??