Hi, and welcome to the site.
I have the qa42a on a 1250 and it works perfectly. For your problem, I would check to make sure the chain has the proper tension (I tightened mine recently because it was a little lose, but it was very easy), and also check the chain and sprocket for wear, if they are worn enough it can cause this problem also. Only other thing i can think of is the chain is misaligned but I don't think that is likely to happen.
|