Stihl MS 311 chainsaw chain question

based on first picture an old chain will stretch that much with 10-20 mins of use. Stop and adjust chain periodically. The common problems with chainsaw chains is overheating which leads to stretching. Usually caused by insufficient lubrication (oil port blocked), bar pinched (bad cutting habit), and more commonly dull/improperly sharpened chain.
 
After you remove a link.
Touch up the guides with a flat file first then sharpen and that saw will rip again.
I prefer running chains a hair tight. My chains never come off unless pinched occasionally in some hairy mess. I do not run a loose chain EVER.
Stop and tighten. Keep them sharp and out of the dirt.
And last it’s probably time to dress and flip that bar upside down if you never have before. The bars are made to be flipped.
After all this your saw will thank you. Hang on both hands tight!
 

bany

Senior Member
You need a new chain. And that one needs to lose a link.
Also dress the bar while you’re at it. Over tightening the chain will also stretch it and wear your bar prematurely.
 

bfriendly

Senior Member
I agree with getting a new chain, but replace the bar too! You surely have it adjusted out as far as it will go(me thinks you know what your doing). But that chain AND bar are both history IMHO....Oregon replacements will do just fine. Also, a bent or wore out Bar end, will wreak havoc on your new chain (the end of your bar looks toast to me)............change out both!
Does the chain slide over the end of the bar easily and smooth while remaining INSIDE the track? ONE tree leaning on and pinching the end of the bar will destroy it.....which will in turn cause friction on the chain and make it HOT and stretch no matter how much oil its getting..
 
At some point the sprocket will get grooves worn in it, if it isn't already,, if you set the chain adjustment with the chain riding on a good spot on the sprocket, and then once running it will fall into the grooves, making it too loose, the sprocket ton my 310 needs replacing for that reason.
 

rayjay

Senior Member
Time for a new chain, bar and sprocket. It looks like the bar has been very hot. If the chain is stretched that bad then the teeth on the clutch sprocket are very worn and will cause a new chain to wear out faster.

You could slide by with just a new chain and flip the bar over. You would need to dress the bar as it surely is worn where it has turned blue from heat.

Wear like this is caused by not keeping the chain sharp and by letting the chain hit the ground which dulls the chain and wears out the rotating parts. I use a Dremel tool and their chainsaw sharpening kit to sharpen my chains. Pretty fool proof and gives good results right off the bat.

I only use Stihl chains. You will most likely be amazed the first time you cut with the new chain. You should buy an owners manual and read it.
 
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