The crank spins freely when the flywheel isnt on or not tight. Heres what worked for me or i thought. I put shim on the crank inside the motor between the front bearings. This works great except i cant get the backplate on before it smashes into crank now. The bearings themselves are fine. I put a gallon through the motor. I dont know. I dont think if i get new bearings it will change anything?