Stihl 026 chain loosening

[Totembear]

Change your rim sprocket while your at it. Its worn.

 

[natej3]

Well I pulled off the clutch and all the case bolts look to be in place. I also checked the cylinder fins and those 4 bolts are present as well. I did have a new cylinder put on last year and I hadn’t cut with it much since then so it is possible that the bolt had been lost/dropped and left in there loose. I took the opportunity to really clean the saw as well. I found that the gap is due to the rubber swelling so I should replace that, as well as the sprocket. After all that, I put the bar and chain on and noticed that the chain seems to bind—it won’t tighten or loosen. When I take the bar off, the tensioner mechanism moves like it should but when the bar and chain go on and I tighten the bolts the tensioner won’t adjust. And, yes I know this was a bad idea, I fired up the saw anyway and the chain flew off and hit me in the leg. I think that I mentioned that I knew it was a bad idea. Just glad my wife didn’t see it

 

[pioneerguy600]

You cannot adjust the chain if the bar nuts are on tight, just can`t tell exactly what you are saying in your last post. The bar nuts must be loose to tension the chain, just saying to be clear.

 

[Jasonrkba]

Loosen the bar nuts, hold the bar up at the nose while adjusting the chain. Once the proper chain tension is achieved tighten the bar nuts while still holding the nose of the bar up. There are good YouTube videos showing how to do this. Do not over tighten the chain and replace the sprocket.

 

[Blueduce]

I think NickC is correct about the cylinder bolt, your not going to fat finger that right rear bolt in there w/out a tweezer.
Dropping that bolt once is almost a sure bet....

 

[drf255]

Check that all 4 cylinder bolts are in.

That sprocket is done. Make sure it’s the same pitch as the chain.

Not too many places that use an M5 bolt that long on an 026. The case bolts, the jug bolts and the coil bolts are all that come to mind. Could be a case bolt, but would have had to found its way out through the oil pump adjust dummy hole, which I doubt. The coil bolts would stay contained in the Fly side and would cause damage. A jug bolt that falls into the void near the impulse line is all I can think of for that bolt.