Did you overtighten the 4 cylinder studs and crack the crankcaseI'm rebuilding my bottom end. My crank spun perfect until I insalled the new seals. Now I have to use some pretty serious force to spin the crank. Is this normal? Please help.
There are no shoulders on a Chinese bicycle engine.Not saying you're wrong but every engine I've seen has a shoulder machined into the case that the seal bottoms against. I've never seen one where the seal could be pressed in too deep. A seal with the wrong inside diameter, too small, could account for it however.