Blow-by

[Sportsterizer]

Ok, let me test your knowledge, well maybe mine.
Did a lower end rebuild on a 93 650. Dumb right, didn't do the top.
Well, the rear seals blew out. Would this be caused by blow-by?
Second, I'm now going to do the top end. Is it necessary to install new pistons or just over-sized rings since I'll be going 10 over on the jugs?

[John Kubiak]

Re: Blow-by

PTO seals blow out due to improper installation, hydrolocking of the engine, or because of a backfire while starting. Boring to 0.010" oversize will require new pistons..