I have two engines, one had been run much more than the other. I took apart the worst one first - that's the one that had the stuck crank pin. Now I took out the less run engine but found it was seized. I flooded it with PB penetrant and throttle body cleaner - it was pretty gunky inside. Probably had fuel sitting inside until it all dried up. I took off the rear starter assy. and the cylinder head. After the cleaners the driveshaft moves freely until the head is at the top of its travel, then there is resistance - you can manually turn the drive shaft past it but my other engine doesn't do this, it moves freely constantly with no resistance. What would this be? I suppose I need to take the piston sleeve out next and then remove the piston to look at the bearings on the crankshaft? Just want to be sure its not normal because it hasn't run nearly as much as the other engine.