Poulan 2300 Bar / Chain Self Tightening

[lil171]

Thanks for all of the tips and things to look for. I will be in the city shopping tomorrow after work, so will pick up one of the nuts described above from the hardware store. While I am at it, I will look for loose engine mounting bolts. If I can find them...

 

[Mauser]

Engine mounting bolts = whatever holds the motor in the case. On the 2900, these are 4 bolts in the bottom; just turn the saw over.

If the motor is free to move around, the drive sprocket does not stay aligned with the bar, and even a minor twist in the case will move the sprocket significantly closer to or further away from the bar, changing the tension.

 

[lil171]

Ok, thank you. I will head out in a few minutes and take a look.

 

[undee70ss]

Check your engine mounting bolts! I almost totally ruined a Poulan 2900 by using it so long with loose and some missing bolts - they ruined the mounting holes in the engine block and I had to re-tap for new bolts. Some of the symptoms I was seeing included the chain being thrown (even with new bar and chain), along with the mysterious changes in chain tension. The engine movement also pretty much ate up the inside of the plastic sprocket cover. I felt pretty stupid when I finally discovered that all the problems were simply due to my own stupidity and poor maintenance!

In fact, I was just putting on a new rim sprocket and dressing the bar on that same saw today, and while I was testing it for good oiling, I ran into the same problem with magically tightening chain. Sometimes it goes suddenly very loose, and other times it goes super tight, all for no obvious reason. Flipped the saw over and found one of the mounting bolts almost out, and another two less than fully tight! Even after the first re-tightening, they started loosening up again VERY quickly - finally had to bear down on those bolts harder than I wanted to stop that game.

Use a thread adhesive to prevent this from happening again. Sometimes some bolts will just come loose on their own no matter how much you tighten them. I would use loctite blue.

 

[Mauser]

Use a thread adhesive to prevent this from happening again. Sometimes some bolts will just come loose on their own no matter how much you tighten them. I would use loctite blue.

Good idea, but absolutely wrong with a plastic saw!!!! Locktite destroys just about any type of plastic, and you do not even need to get it directly on the plastic - just the fumes will do the damage.

 

[Ginger15]

I've used locktite on several cylinder bolts on plastic saws, going on years, never had a problem. If you want to be that careful then use locktite 425 which is used for metal to plastic, but the bolts are metal to metal. So normal locktite is fine.

 

[Mauser]

You do what you want, but this is a problem we learned in the motorcycle world many years ago. LOTS of expensive plastic parts have had to be replaced while the owners wailed that they wished someone had told them. The Locktite does not melt the plastic like a solvent, but it seems to affect the molecular structure somehow. My advice is that one should never use Locktite on any bolt that goes through a plastic part.

 

[scottr]

lil171 , I have seen a similar problem caused by a partially stripped bar adjust screw and pawl .

Mauser , the Poulan 2300 has a magnesium crankcase , it is not a clam shell design like your 2900 .

 

[lil171]

Thanks scottr. I can easily look at the screw when I take it apart next time. I was cutting some wood again today but it is misting and drizzling out so I just used my new saw today. However, I left me a few bigger logs to play with using my 2300. I will first try it again now after tightning it again, and if it fails again, I will take it apart to look at the screw as you mentioned. That is one thing I had never thought of. Thank you.