Stihl 261 muffler mod question

[Highdesignfool]

So I'm finally getting around to doing the muffler mod on my NON mtronic 261. I cut the gills in the left side of the muffler, took out the screen also. Is there any more that should be done?
What's the consensus?

 

[Redfin]

Open up under the screen holder.

 

[Highdesignfool]

Open up under the screen holder.

Within the deflector or below? How much?

 

[Redfin]

As much as you can under the deflector.

 

[Redfin]

Get rid of those limiters. 261 likes abit more fuel to run at its peak.

 

[Highdesignfool]

As much as you can under the deflector.

Thumbs down

 

[Highdesignfool]

Get rid of those limiters. 261 likes abit more fuel to run at its peak.

I drilled out the pin that limits the travel on the H screw. That went great, just need to buy a tach

 

[Chainsaw Jim]

Under the deflector, not below. Some might even say "within the deflector".

 

[Highdesignfool]

Under the deflector, not below. Some might even say "within the deflector".

Does that look like enough?

 

[Chainsaw Jim]

Does that look like enough?

Not if the channel feeding the screen wasn't cut open, removed or partially removed. A ball burr is about the best tool to use for this. You grind a hole through the channel where I have it marked. I don't like to grind it open too far forward because the deflector won't be able to direct the flow.

 

[Highdesignfool]

Not if the channel feeding the screen wasn't cut open, removed or partially removed. A ball burr is about the best tool to use for this. You grind a hole through the channel where I have it marked. I don't like to grind it open too far forward because the deflector won't be able to direct the flow. View attachment 104542

Are you saying the channel that the screen sits in needs to be removed?

 

[Redfin]

This is the way I have done a few 261s. I prefer to keep a screen in all my builds but it is replaced with one more open.

 

[Redfin]

Starter side outlet will get nutserts with 8/32 and a screen.

 

[Redfin]

 

[Joseph]

• Hello at all

I would ask every body about return of expérience of muffler mod on ms 261 Electronic ( or not Electronic )

The first modif have 6 or 7 years now

So What about the gain of power after long time of use ?

What about éventual fail or broken engine ?

Or else news

Thanks a lot for answer

Jo

 

[smokey7]

Mods on a ms 261 ive only done 1 and it responded very well. It was a carbed saw and actually needed leaned out some after. Defiantly gained rpm and power. I just modded the stock outlet under the stock deflector. Actually extended the stock deflector some as it was coming out the side a little too miluch for my taste. Most saws i much prefer a single outlet over duel ports for performance and sound. I think duel ports have a crappy sound to them and i figure exhaust flows in a column of air and splitting up that air would probably not do it any good. Sorry for the ramble but that is my experience with them.

 

[RI Chevy]

Interesting theory there. I never thought about exhaust like that in a singular path.

 

[Evan03]

I to like to build my mufflers with a single outlet. On 2 stroke machines

 

[Country96]

this is what i did to the muffler on my 261, and then reset mtronic, can anyone see any issues doing it this way? thanks

 

[RI Chevy]

YOU MAY GO DEAF!
But how does the saw run?
Any vids?