Stihl MS 261 rebuild questions

[PETDOC]

I live on 20 heavily wooded acres near the Great Smoky Mt. Natl. Pk. and for 24 years had harvested dead and fallen trees for firewood with a Husquvarna 51. Sadly it was pancaked when I finished dropping a large ash tree with wedges. Wanting an equally powerful, but lighter saw, 17 months ago I purchased a Stihl MS 261 C-M with the requisite 6 units of oil to double the 1 year warranty. Since owning the MS 261 I've cut down ~30 trees (20 small to medium sized cedars, 1 very large loblolly pine and 9 hardwoods). Recently while facing a cedar post to attach a sign the saw began to slow then with a puff of white smoke abruptly seized up. After it cooled I could cycle the piston, but had no compression. I dropped it off at dealer assuming the warranty would cover the repair, but was told the damage was at exhaust port and predicted Stihl will claim I 'abused' saw and not pay. Have yet to hear from Stihl, but assuming the worst I have researched acquiring parts for a rebuild, hence I found HL Supply and this forum. Having been an avid motorcyclist I've serviced and repaired all of my bikes, but never a 2-stroke.
I've got 2 quick questions:
1. Based on reading posts on this forum my assumption is the very best non-OEM top end would be the Italian Meteor kit?
2. My plan would be to check for any possible air leaks during disassembly, rebuild top end and then take it to shop for pressure testing and test/readjust carburetor. Does this seem reasonable?
Grateful for any advice.
Thanks Dave

 

[DND 9000]

I don`t know if Meteor for example already has a cylinder kit for the newer slanted fin cylinder MS 261 C-M. The older cylinder version can`t be used with the newer updated MS 261 C-M. The 261 was redesigned and updated in 2015. It`s possible that you have to take the OEM cylinder.

Your plan checking for air leaks is a good idea. Do this before you have it appart, and if you rebuild it, do it after the rebuild again. Also take new rubber parts to have a good sealing.

Going to the dealer for the initial setup after the rebuild is good, but you can also recalibrate it by yourself.

When your saw seized up, how did you ran it? Was there a lot of part throttle use? M-tronic needs full throttle phases and load to tune itself right. Part throttle can confuse the m-tronic system, if it`s to much. I would also have the dealer see what the stored last fuel settings are now on the control unit. That may help diagnose the reason why it seized up.

 

[PETDOC]

I don`t know if Meteor for example already has a cylinder kit for the newer slanted fin cylinder MS 261 C-M. The older cylinder version can`t be used with the newer updated MS 261 C-M. The 261 was redesigned and updated in 2015. It`s possible that you have to take the OEM cylinder.

Your plan checking for air leaks is a good idea. Do this before you have it appart, and if you rebuild it, do it after the rebuild again. Also take new rubber parts to have a good sealing.

Going to the dealer for the initial setup after the rebuild is good, but you can also recalibrate it by yourself.

When your saw seized up, how did you ran it? Was there a lot of part throttle use? M-tronic needs full throttle phases and load to tune itself right. Part throttle can confuse the m-tronic system, if it`s to much. I would also have the dealer see what the stored last fuel settings are now on the control unit. That may help diagnose the reason why it seized up.

Thanks for the advice. Regarding the chainsaw operation-I made 2 quick horizontal cuts about 1/2" into face of ~4" diameter cedar post 12" apart and then chiseled out a narrow flat surface on which to mount a wooden sign. Most of the time I had the saw going full throttle. It began to slow down suddenly as though it was running out of fuel, then abruptly stopped. There was a puff of white smoke and some oil below where the bar mounted. I had checked the chain oiler at the beginning (i.e. oil splatter on the post) and it was fine. When I removed the side cover and checked the oil channel on the bar it was clear.

 

[NCPT]

Unless your gas mix was off (or straight gas), I dont see why stihl wouldn't warranty it?

If they dont cover it, and you fix it yourself, you need to figure out what caused the damage before you buy any parts.

 

[PETDOC]

Gas mix was correct. Exon ethanol-free gasoline with Stihl oil. I always rock the gas container before filling up the saw, but have read the Stihl oil doesn't settle out.
I dropped by another Stihl dealer and told them my story. They gave me the same answer 'Stihl will not likely cover the repair'. The guy said Stihl only covers a defective part, e.g., bad bearing, etc, and considers seizure as overheating and operator error. I asked if it would be worth contacting customer service and argue my case. He said that sometimes will get them to supply parts. I have yet to hear anything, but will post the response.

 

[lehman live edge slab]

Check another dealer if the one you tried won’t work with stihl to make it right. E-free gas and stihl oil then stihl has no reason to turn it down. Even if it sucked a crank seal so what not like you leaned the jets out or straight gassed it.

 

[lehman live edge slab]

261 is pro saw designed for heavy uses 25-30 trees in 17 months isn’t heavy use. I could see the dealer laughing if you bought an ms 170 to cut 24”+ oak, ash and hard maple

 

[PETDOC]

Yes my use of a chainsaw is limited. That associated with my care of the saw really set me up for a major disappointment after hearing the 2 Stihl dealers make the same comment on warranty coverage. Wish I hadn't crushed my Husquvarna 51. I have yet to get official word from Stihl so my pessimism may be misplaced.

 

[lehman live edge slab]

Happens with all brands and dealers, my buddy bought a husky 350 from a local shop bought six pack of oil at same time. Saw blew up about 8-9 months after he got it. Dealer told him that it was wrong oil and not covered. He showed him the receipt for saw and oil they said too bad was bad gas. I looked at it later and the muffler was loose which caused it to score. Only way I could tell is oil tank was melted a little. Then another guy from work at same dealer brought his 357 in with snapped off pto crank end gone. They told him was do to not greasing the clutch drum needle. It tempered the crank and that’s why it broke but the needle bearing was completely intact and spinning. I told him definitely a line of bs. The guy that had the 350 bought a gen 1 ms261c and loves it, cuts 25-30 chords a year for last 4-5 years.

 

[drf256]

Truly believe MT came about to reduce warranty issues. It can compensate for small air leaks and should prevent a saw from frying most times.

If you do have a C-M, there is no carb to adjust. There’s a chance something went awry with the MT system causing the saw to fry. It also can just be some mechanical issue with the saw.

Bring it to another dealer. Get it diagnosed.

 

[PETDOC]

While awaiting word from Stihl Corp. on warranty coverage I've been scanning threads on ms 261 in chainsaw forums here and in Europe and I'm getting the impression I may have purchased the "Edsel" of Stihl chainsaws. Apparently there have been a number of crank shaft failures and problems with sprocket bearing. Suggested remedies on threads have included a 40:1 vs 50:1 gas/oil mix and re-greasing sprocket bearing whenever chain is sharpened.
I'm curious if there are people with the 261 C-M that have had several years of reliable use with normal maintenance?

 

[lehman live edge slab]

I don’t think I’ve heard much of anyone having lower end issues, personally know 4 people with them and nobody’s had issues. One guy has a tree service and the other 3 have had the version one ms 261’s for 5 years cutting 15-20 chords a year plus whatever dead trees on property ect. All run 50:1 with stihl ultra or Husqvarna xp oil. Not that five is that many people but they have been flawless for them minus one guy burining a bar up from the Oiler not being turned up.

 

[drf256]

While awaiting word from Stihl Corp. on warranty coverage I've been scanning threads on ms 261 in chainsaw forums here and in Europe and I'm getting the impression I may have purchased the "Edsel" of Stihl chainsaws. Apparently there have been a number of crank shaft failures and problems with sprocket bearing. Suggested remedies on threads have included a 40:1 vs 50:1 gas/oil mix and re-greasing sprocket bearing whenever chain is sharpened.
I'm curious if there are people with the 261 C-M that have had several years of reliable use with normal maintenance?

If you bought it 18 months ago, you didn’t get one with the problems. There are growing pains with any new equipment models.

It’s a great design that really has few problems and makes a lot of power for its displacement.

The problem lies in the fact that the “foolproof” MT system isn’t always so, and when it’s fails it’s tough to diagnose. It’s also tough to know what to blame for the failure when there is an auto system that could have intermittent problems.

The system creates a crutch where one tends to pay less attention to the saw tune, assuming it will always be ok. As there is no way to adjust, that part is out of the equation during its use.

I like automatic pistols a whole bunch, but if I had to pick one weapon to protect my life with it would be a revolver. One trades simplicity for better all around performance. Simplicity will always win with all out reliability-like points in a distributor.

I still like non-auto tune saws myself for the above reasons.

 

[pwheel]

...It’s a great design that really has few problems and makes a lot of power for its displacement.

The problem lies in the fact that the “foolproof” MT system isn’t always so, and when it’s fails it’s tough to diagnose. It’s also tough to know what to blame for the failure when there is an auto system that could have intermittent problems. ...

I still like non-auto tune saws...

Until the MS462 arrived, the local power shop would not sell you a Stihl auto-tune saw. Too many problems. According the lead tech (old school), if the saw won't run, there's no way to run diagnostics. I came by a used standard carb MS261 built in late 2012, replaced the carb diaphragms and I couldn't ask for a better saw.

 

[deraeler]

I purchased an ms261c in 2014, it appears to be a 2013 model. I've never used anything except steals own HP Ultra oil and I treated the saw very very well. It just died with scoring on the exhaust side of the cylinder. Can't determine the cause for this. I was told by my dealer that a Stihl cylinder rebuild kit would cost approximately $400. So obviously they recommended buying a new saw. Can anyone recommend a third-party cylinder rebuild kit? I also read here where they did some redesign on the saw in 2015 so I would need something that's compatible with the 2013 model. Any and all insights very much appreciated.

 

[lehman live edge slab]

I’d pull it down and look cylinder might be just fine so all you’d need is a 50$ meteor piston or oem your choice and a gasket set. Also vacuum test to see if you have an air leak because the mtronic can actually tune a pretty substantial air leak out.

 

[PETDOC]

I purchased an ms261c in 2014, it appears to be a 2013 model. I've never used anything except steals own HP Ultra oil and I treated the saw very very well. It just died with scoring on the exhaust side of the cylinder. Can't determine the cause for this. I was told by my dealer that a Stihl cylinder rebuild kit would cost approximately $400. So obviously they recommended buying a new saw. Can anyone recommend a third-party cylinder rebuild kit? I also read here where they did some redesign on the saw in 2015 so I would need something that's compatible with the 2013 model. Any and all insights very much appreciated.

I purchased my MS261C-M early 2018 so may have been a late 2017 or an early 2018 model. Met same fate as yours after minimal use and optimal care. The dealer said they require factor rep. authorization for warranty repair and he sincerely doubted Stihl rep would approve it. It took over 1 month to finally get approval. In the meantime I researched all the parts for rebuild. If warranty was denied I was going to rebuild it myself. I could never find an aftermarket slant fin cylinder head, only the older flat fin model. After my dealer rebuild I looked at the parts and he had installed the old style flat fin head. I objected, but he showed me on his computer that Stihl would not permit him to purchase the newer slant fin head. Every time he clicked on the slant fin the computer redirected him to the older version. It has worked fine since rebuild, but after reading stories of numerous failures and recommendations to use a 40:1 oil:gas mix that's what I’ve done. (A side note- to tide me over during the absence of my MS261, I purchased Stihl's 60V battery powered chainsaw. I've owned a half dozen chainsaws in my life, and hands down the 60V battery powered saw is the most useful saw I’ve ever owned.)

 

[DND 9000]

....so I would need something that's compatible with the 2013 model. Any and all insights very much appreciated.

For example on sawagain.com is a piston and cylinder kit from Meteor for the MS 261 (replaces Stihl piston and cylinder 1141 020 1200). That part no. fit`s your 2013 model. Also do a search for it and I`m sure you`ll be able to find a solution.

https://www.sawagain.com/meteor-cylinder-kit-fits-stihl-ms-261-11410201200/

 

[deraeler]

Really appreciate the replies folks! I Admit to being a newb so please bear with me. What equipment do I need to do a vacuum test? Since this is an m-tronic model I need to have a dealer tune it once the rebuild is done right? Any video tutorials available on this? Only found German ones on YT....and I don't speaka da deutsch.

 

[deraeler]

Looking on sawagain.com they must have pulled their video How-To's on the saw rebuild process. Could really use some resources.
I can't even figure out how my dealer got the muffler off....how do you get to the screws inside the muffler that screw into the exhaust port? (Need a service manual!!)