Stihl MS271 Farm Boss engine failure

[Jeremy Chatterton]

I bought my MS271 brand new about 10 years ago and have put many MANY hours on it. It has been my "go-to" saw for every day use. A few days ago I was cutting some trees for firewood and had been running the saw for about 30-45 mins. It was running normally and then just quit. No indications of anything weird before the failure. It had plenty of gas and bar oil. It just QUIT! When I went to restart it, I could not pull the cord. I removed the spark plug and still could not pull the cord. I knew it was something internal and took it back to my garage. I have attached pics of the piston and the cylinder walls. It looks like something got into the cylinder and gouged the piston and cylinder wall. The gouge was way too deep to even think about re-surfacing/honing the cylinder. It was toast. My question to all of the knowledgeable folks on here is: What could possibly cause this to happen?? My fuel filter was relatively new, I think I replaced it last summer. It looked perfectly clean when I disassembled the saw and the fuel tank was really clean. I really can't figure out what could have caused this. Have any of you had this happen?
IMG_3864.jpgIMG_3869.jpg IMG_3865.jpg

[Tom M King]

Check the little roller cage bearing in the top of the connecting rod. Were the keeper clips on the end of the wrist pin? If it just shed a clip a piston and cylinder kit will put it back to work. If that little roller bearing is shredded, it will probably need a whole new crank assembly plus seals and cylinder kit, which puts the price of parts more than half the cost of a new saw. Check for slop in the main bearings while the cylinder is off too.

Only use OEM clips regardless of where the other parts come from.

Aftermarket parts are a lot cheaper, but they're a lot cheaper.

[Edward Weber]

Exactly what I was going to say, the photo sort of confirms it.

[Tom M King]

Thinking about this some more, I've never been in the bottom end of a homeowner grade saw. I understand they're not as easy to work on as a Pro saw is. I looked, and it's a $500 saw. If you need to buy a new one, I suggest treating yourself to a MS261cm. It's a couple of hundred dollars more, but a Pro grade saw, lighter weight with more power than the 271.

I googled for a comparison and found this: [COLOR=var(--YLNNHc)]What is the difference between ms261 and ms271?[/COLOR]



[COLOR=var(--bbQxAb)]The 261 is a mag case, easier to work on and rebuild, more power, lighter. The 271 is more plastic, heavier, and a little more difficult to work on for the avg joe at least. The 271 if probably fine for the avg joe that justs cuts a little firewood.




[/COLOR]

[Larry Frank]

Were the rings intact when you took it apart? A broken ring could cause such damage.

[Brian Elfert]

Thinking about this some more, I've never been in the bottom end of a homeowner grade saw. I understand they're not as easy to work on as a Pro saw is. I looked, and it's a $500 saw. If you need to buy a new one, I suggest treating yourself to a MS261cm. It's a couple of hundred dollars more, but a Pro grade saw, lighter weight with more power than the 271.

A $500 chainsaw is considered homeowner grade? I always thought the homeowner grade saws are the $200 to $300 saws, and $500 gets you something pretty good.

[roger wiegand]

A $500 chainsaw is considered homeowner grade? I always thought the homeowner grade saws are the $200 to $300 saws, and $500 gets you something pretty good.

For $tihl you need to move the decimal point over ;-) they strictly control their retail pricing, no discounts. Good saws, though, even the "homeowner" grade-- they will run rings around the cheap saws from the Borg.

[Brian Elfert]

For $tihl you need to move the decimal point over ;-) they strictly control their retail pricing, no discounts. Good saws, though, even the "homeowner" grade-- they will run rings around the cheap saws from the Borg.

I was thinking about chainsaws in general, not just Stihl. I have an inexpensive Echo chainsaw, but it won't start after sitting with fuel in it for years. I have been using a cordless chainsaw instead.

[George Yetka]

I hate to be the guy but how much do you use the saw? I switched off the stihl to a milwaukee 3 years back and have sleep better not having to maintain any 2 strokes anymore. My issue was that I used it a couple times a year and was borrowed a couple times a year. So everytime I used it I would have to put a new blade on it and half the times I would have to overhaul it to get it running.

The milwaukee is super fast do to the narrow bar and chain and with 2 big batteries you can cut for a couple hours.They do overheat so you have to swap back and forth every 10-20 minutes. The stihl I gave to the family so if anyone needs to borrow they have to get it running if they want it.

If I were using a saw weekly or more than I would still use gas or if I was cutting very large stuff

[Tom M King]

Those cordless saws are easy to start, but they won't do this to a dry Maple. I thought I'd just be cutting Pines that a big blow blew down across our trails that day, but we came up on this dead maple, so I just used the saw I had set up for Pine. This a hot rod 066 pulling a 10 tooth sprocket.

https://www.youtube.com/watch?v=R2cdN53BxGs

[Edward Weber]

I have a 270, the precursor to the OP's saw. It's been running fine for 20 years. They are a good quality saw, period.
As always, depending on how often you use your saw and the type of cutting, it may be worth while to simply rebuild it.
A new cylinder kit and a few other parts can have it like new for less than $200, in most cases.

[George Yetka]

Those cordless saws are easy to start, but they won't do this to a dry Maple. I thought I'd just be cutting Pines that a big blow blew down across our trails that day, but we came up on this dead maple, so I just used the saw I had set up for Pine. This a hot rod 066 pulling a 10 tooth sprocket.

https://www.youtube.com/watch?v=R2cdN53BxGs

Tom I agree that is ideal to have a nice saw setup like that I just wasnt using it enough and everytime I had it tuned and sharp someone would borrow it to cut roots(always so dull when it came back). But I did cut up a 30" tree last summer with the Milwaukee.

[Tom M King]

I like cordless saws for some things too. I keep a little one and a polesaw in my truck toolbox. I like to use them when up in a lift bucket too instead of having to start a gas one.

I keep a couple of saws for loaning out. I tell whoever wants to borrow one that they are hard to start. They are.

[Maurice Mcmurry]

I bought my MS271 brand new about 10 years ago and have put many MANY hours on it. It has been my "go-to" saw for every day use. A few days ago I was cutting some trees for firewood and had been running the saw for about 30-45 mins. It was running normally and then just quit. No indications of anything weird before the failure. It had plenty of gas and bar oil. It just QUIT! When I went to restart it, I could not pull the cord. I removed the spark plug and still could not pull the cord. I knew it was something internal and took it back to my garage. I have attached pics of the piston and the cylinder walls. It looks like something got into the cylinder and gouged the piston and cylinder wall. The gouge was way too deep to even think about re-surfacing/honing the cylinder. It was toast. My question to all of the knowledgeable folks on here is: What could possibly cause this to happen?? My fuel filter was relatively new, I think I replaced it last summer. It looked perfectly clean when I disassembled the saw and the fuel tank was really clean. I really can't figure out what could have caused this. Have any of you had this happen?
IMG_3864.jpgIMG_3869.jpg IMG_3865.jpg

That looks like a classic case of gas only to me.

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[Edward Weber]

I keep a couple of saws for loaning out. I tell whoever wants to borrow one that they are hard to start. They are.

loaning out ????
no tools lent out, to anyone, ever
(this is an entire thread itself)