I have a 110 quad engine that has a hard spot when spinning the engine over by hand while checking the timing. Spark plug is out while spinning it over. It has a spot where it feels like the engine binds slitely then move free thru the rest of the rotation. To me this is a crank shaft main bearing issue. Anyone else have this problem? Thanks in advance.

 

Probably just the camshaft shoving the valves down. However if it really is binding on something, it is unlikely to be mains, a loose stator, or the piston partly seized are far more likely causes of a tight spot.