Help please! Trouble finding ms261-c replacement piston.

[Hkeyees]

Hello,
First off- I've been lurking around this forum for a couple years now reading about saw repair and modification. I finally joined and this is my first post.


I have a stihl ms261c m-tronic that appears to have scoring on the exhaust side, I haven't pulled it yet because I wanted to be sure I could track down the parts before getting in too deep.


I've done many searches and haven't been able to find my answer yet.
Some sites list the piston/cylinder kit as fitting both the ms261 and ms261-c, and other places I've read that the 2 are different.

Can someone point me in the right direction please? Also, are they any aftermarket brands that are good and ones that I should avoid when it comes to pistons and cylinders?

This 261c is an awesome saw, I'm really hoping I can save it.

I was considering having it professionally ported and the piston replaced at that time, but it seems that wicked work saws in east TN has disappeared and I can't find anyone else to do it.

Thanks In advance.

 

[blsnelling]

Go to your dealer. A new piston is probably only $35-$45. Forget aftermarket.

 

[tree monkey]

oem pistons are $36.6o
and I'm right here, I like porting saws

 

[lone wolf]

Go to your dealer. A new piston is probably only $35-$45. Forget aftermarket.

Are they the same the mtronic and non mtronic pistons would you happen to know Brad? I would think they are.

 

[big t double]

Are they the same the mtronic and non mtronic pistons would you happen to know Brad? I would think they are.

not trying to talk for blsnelling but yes...they are the same for both versions. 1141 030 2012

 

[lone wolf]

not trying to talk for blsnelling but yes...they are the same for both versions. 1141 030 2012

I thought so. Thanks. Do you have a 261C?

 

[big t double]

I thought so. Thanks. Do you have a 261C?

nope...just the regular carby version. good saw...I have a couple 026's im going to sell because the 261 makes them obsolete in my opinion.

 

[lone wolf]

nope...just the regular carby version. good saw...I have a couple 026's im going to sell because the 261 makes them obsolete in my opinion.

I was wondering if the Mtronic runs stronger then the carb versions . I have one with a carb already.

 

[SteveSS]

How old is the saw, and what is the root cause of the scoring? Mtronic should have adjusted the fuel mixture to prevent any type of lean scoring, I'd think. Is it possible that your saw is still under warranty and needs a check out at the dealer? Just wondering out loud...

Pics?

 

[Hkeyees]

Thank you for all of the replies, I've attached photos in the original listing.

 

[Hkeyees]

I'm unsure of the saw's age. I purchased the saw used. I didn't think the m-tronics could run lean so my assumption is that someone used straight gas.

The cylinder itself has hairline scratch marks (very light) with the exception of a larger gouge right below the intake port. I can feel this one with my fingernail.

Is it possible that there could be further problems besides just the cylinder and piston? Would the m-tronic compensate for an air-leak?

 

[old guy]

That doesn't look seized to me, looks like something got in there.

John

 

[Hkeyees]

That's a good point, I didn't even consider something getting in there.

Do you think the cylinder needs to be replaced or is it save-able?

 

[old guy]

It all depends on how deep that scratch is, I can't tell from here, my guess is it needs to be replaced.

John

 

[tree monkey]

I think the cylinder is good, did you find anything in he case or muffler that would help determine where it came from?

 

[angelo c]

Is it wayyyyy too early in the morning or is that in intake side?
More common to score the intake side with FOD then leaning IMO. By looking at that gouge in the cyl I'm saying that's not transfer.
What do the bearings look/feel or sound like...

 

[whitedogone]

Judging from the pics, I would run that jug. I don't think I'd want to drop the change to have that one ported though. New oem piston and rings...gtg

 

[Hkeyees]

Before I pulled the cylinder it started right up, ran and cut just fine, but after running for about 30 seconds it would start to make a racket. Like a rattling/vibrating noise.
The compression was reading 150psi on 4-5 pulls also right before I dismantled it.


I'm far from an expert, but I couldn't feel any play in the crankshaft or piston.

I'll double check for foreign matter, but I haven't came across any yet.

Thanks for all the replies!

 

[Hkeyees]

It looks like there might be some fine metal chips in the crankcase, but other than that I didn't see any objects In there or in exhaust.

Is it common for objects to get inside the cylinder and damage it? Nothing can get in there except through the fuel/carb or something falling down in it while changing the plug right?

 

[tree monkey]

sounds like a bearing