Top End Ate two cranks.

[afleetcommand]

So in general terms sometimes it causes some alarm if the bore is out of spec and it could be the piston pin is askew on some of this after market stuff .Then again if the crank and pin bearing had some slop it might not have happened .For that matter it might have ran forever until it rattled itself apart .

yup...and there will be a "tolerance stack" from everything starting from the bearing pockets in the cases! Crank, bearing slop, cylinder....problem here was I jumped to conclusion based on the look vs. the true measurement of the cranks. One of those you SEE this hand, but miss the one about to deck you. My bet is as MM mentioned, even the best is out some. This was out to the point the rod bearings failed first....then the piston started smacking the squish band until it broke. A mess. A cross WJL & friend. Had "Hy" hopes for that setup! LOL

 

[sunfish]

What saw/kind of top end

It must be a secret?

 

[Mastermind]

It must be a secret?

I think he said it was a Cross top end in his last post.

I assumed that it was. They are supposed to be top notch. I have one in service on a friend's saw that is doing well, but we all know Chinese manufacturing QC for saw parts is not great at this point.