MS261 C-M mod question

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Stihl-y Dan

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Hi everyone, im new here and very grateful for all the sage advice, saw reviews, etc... I am well impressed with the depth of knowledge here. Cheers, all!

So my question is this: if i am going to do a muffler mod on a MS261 C-M, do i need to remove the carb limiters or can the M Tronic compensate adequately? I have read some posts on this and some members say that you would. I will not port, but I will completely remove the baffle in the muffler and add 3 or 4 "gills" as i have seen in member photos... just wondering if i open it up too much, is that why some members say the carb has to have the limiters removed and then re-tune?
 
With the c/mtronic you just have to let it idle for 60s i think for it to tune itself. Someone with better knowledge will chime in. I own carb saws


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Hi everyone, im new here and very grateful for all the sage advice, saw reviews, etc... I am well impressed with the depth of knowledge here. Cheers, all!

So my question is this: if i am going to do a muffler mod on a MS261 C-M, do i need to remove the carb limiters or can the M Tronic compensate adequately? I have read some posts on this and some members say that you would. I will not port, but I will completely remove the baffle in the muffler and add 3 or 4 "gills" as i have seen in member photos... just wondering if i open it up too much, is that why some members say the carb has to have the limiters removed and then re-tune?

There is no baffle in the newer 261 mufflers. It's part of the reason they run better in stock trim compared to the older ones.

No carb limiters in m-tronic.
 
Cheers, thanks all. The warranty just expired so I still havent taken it apart yet to do anything other than clean the filter and swap the plug once. No baffle in the 261 Mtronic? Good tip, didnt know that! Thanks for the replies, I coulda swore I read a thread on modding a 261 Mtronic where someone mentioned limiters on the carb. Thanks for clearing that up makes sense... lol
 
Cheers, thanks all. The warranty just expired so I still havent taken it apart yet to do anything other than clean the filter and swap the plug once. No baffle in the 261 Mtronic? Good tip, didnt know that! Thanks for the replies, I coulda swore I read a thread on modding a 261 Mtronic where someone mentioned limiters on the carb. Thanks for clearing that up makes sense... lol

There is a tube in the older style mufflers that's hard to see looking in from the exhaust side, it's a performance killer.

What year is your saw ? Is it a version 2 ?
 
Cheers, thanks all. The warranty just expired so I still havent taken it apart yet to do anything other than clean the filter and swap the plug once. No baffle in the 261 Mtronic? Good tip, didnt know that! Thanks for the replies, I coulda swore I read a thread on modding a 261 Mtronic where someone mentioned limiters on the carb. Thanks for clearing that up makes sense... lol
tinkeridis KILLS GOOD STIHL SAWS ,,,leave it alone an use it if its Mtronic.if you dont your asking for trouble.
 
This is what I did with mine and what a lot of people do. Make 3 slices with a dremel cutoff wheel then bend the fins with a pair of duckbill pliers. Make sure you remove the muffler before you do this and clean it well before reinstalling. There’s a lot of gain doing this along with the timing advance. IMO this is all this saw needs done.

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The Mtronic system will adjust for the majority of mods, up to and including muffler modifications, porting, and timing advances.

There will be NO adverse effects from a muffler mod as Short Timer describes above (other than increased noise that is). I have this exact mod on my 261c muffler, albeit with 4 slots, and countless hours on the saw after the mod with nothing but positive results.

If a saw is a conventional carbureted saw, then yes, you would need to richen the H jet on the carb to offset the muffler mod or possibly suffer a lean condition.
 
The Mtronic system will adjust for the majority of mods, up to and including muffler modifications, porting, and timing advances.

There will be NO adverse effects from a muffler mod as Short Timer describes above (other than increased noise that is). I have this exact mod on my 261c muffler, albeit with 4 slots, and countless hours on the saw after the mod with nothing but positive results.

If a saw is a conventional carbureted saw, then yes, you would need to richen the H jet on the carb to offset the muffler mod or possibly suffer a lean condition.
Spot on.

Amazing to me what disinformation gets thrown around here.
 
just wait an see who is right..seen it time an time again.it messes the Chip on the Mtronic module up.why would you think Stihl wouldnt do that to start with? and no it isnt because of EPA either.its called a lot of testing on Stihls part to make a product that lasts not a tinker toy.
 
just wait an see who is right..seen it time an time again.it messes the Chip on the Mtronic module up.why would you think Stihl wouldnt do that to start with? and no it isnt because of EPA either.its called a lot of testing on Stihls part to make a product that lasts not a tinker toy.
How long should we wait? How many hours? You know how many since you pulled the time off the computer when you’ve seen this “hundres of times”.
 
just wait an see who is right..seen it time an time again.it messes the Chip on the Mtronic module up.why would you think Stihl wouldnt do that to start with? and no it isnt because of EPA either.its called a lot of testing on Stihls part to make a product that lasts not a tinker toy.

WRONG. Modifying the muffler doesn't "mess with the chip".

You have ZERO clue about that of which you speak.
 
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