Stihl MS271 crushed

[Wilfman825]

I've had this saw a couple years, have maybe 10 hours on it. I had a tree start falling but only tilted 10 or 15 degrees before it became entangled on those around it. Long story short I got the saw stuck while cutting through the remaining wood fibers between the notch and the back cut. No problem, I attached the tow rope to the tree and snatched it off the remaining log. I have no idea how physics managed to let this happen but the saw fell, flipped under the tree, and was.. piledriven?

I'm attempting to revive this one before I commit to getting the MS261 I've been wanting. If the engine on the damaged MS271 is repairable within reason I'll look into getting a new handle and some new plastics.

When I attempt to turn the engine over there is more resistance than there was before. Seems like it is only in one spot, aligns perfectly with the compression stroke. I stripped the powerhead down and I can tell when I slowly turn the engine over by hand that the flywheel has a high spot. In other words the distance from the engine to the edge of the flywheel varies as the engine is turned over.

How can I determine whether the flywheel is bent or if the crankshaft is bent? If it is the crank I would be tempted to bang on the high spot with a piece of wood to attempt to straighten it and get some more life out the powerhead. Depends on the cost of a crank I guess. Any input is appreciated!

Dang man wow that's not good sorry about the 271 RIP sorry hard way to learn valuable lesson

 

[Pripyat]

I wasn't expecting all my parts until Saturday. Surprisingly everything but the bar came in yesterday around noon. I threw on the new parts, cleaned the air filter, and the saw started right up. Runs good with no load - The bar will be here this weekend, I expect to finally get the tree out my front yard. I do need to tune the carburetor, though - I don't know the correct terminology for 2 strokes but it doesn't seem to idle smoothly. It isn't like it is skipping but it is almost like every other revolution is a more powerful stroke. Or in other words it vibrates a LOT. I'm assuming getting the caked on dust out the air filter is causing it to run lean?

Anyway, I'm sure there is a great tutorial someone can point me to.

 

[HarleyT]

Is the flywheel gap even all around the circumference of the flywheel?

 

[user 122190]

I too am skeptical that after being crushed, replacing some parts, that now it is the carburetor that is all that effects the run. This saw might have an arms length list of problems that need to be found and corrected.

Is the flywheel gap even all around the circumference of the flywheel?

 

[Pripyat]

Well I noticed that the idle wasn't quite right when I was using it to cut the tree that fell on the saw. I let a guy borrow it a while back and he said that he "had to tune it". It hasn't run the same (correctly) since. It never bogs but the idle doesn't seem as smooth as before. Same now - It runs fine but I can't shake the feeling that it needs to be adjusted. I didn't do a full evaluation of the flywheel but I do plan to pull that cover back off and check it to be sure. I glanced at it when I had pushed the flywheel on by hand but not after I ran the nut down. I'll work on making a video of the saw idling so you guys can see if you can make any determinations.

 

[nighthunter]

Put up a video of it running, post it to YouTube and share a link here

 

[user 122190]

Good sound reasoning. Sounds like you got very lucky in resurrecting this saw from what would normally be a throwaway, or at best a parts donor.

Well I noticed that the idle wasn't quite right when I was using it to cut the tree that fell on the saw. I let a guy borrow it a while back and he said that he "had to tune it". It hasn't run the same (correctly) since. It never bogs but the idle doesn't seem as smooth as before. Same now - It runs fine but I can't shake the feeling that it needs to be adjusted. I didn't do a full evaluation of the flywheel but I do plan to pull that cover back off and check it to be sure. I glanced at it when I had pushed the flywheel on by hand but not after I ran the nut down. I'll work on making a video of the saw idling so you guys can see if you can make any determinations.

 

[HarleyT]

Or in other words it vibrates a LOT

I would explore this a bit.

 

[Overkill338]

Well I noticed that the idle wasn't quite right when I was using it to cut the tree that fell on the saw. I let a guy borrow it a while back and he said that he "had to tune it". It hasn't run the same (correctly) since. It never bogs but the idle doesn't seem as smooth as before. Same now - It runs fine but I can't shake the feeling that it needs to be adjusted. I didn't do a full evaluation of the flywheel but I do plan to pull that cover back off and check it to be sure. I glanced at it when I had pushed the flywheel on by hand but not after I ran the nut down. I'll work on making a video of the saw idling so you guys can see if you can make any determinations.

Never ever ever, loan out your chainsaw or your wife!