I just went over 4000KM on my prowler and my engine died. Pulled the cylinder and piston they were both scored up pretty bad, so I ordered the Big Bore Kit 650-700 for it. Then I noticed that the crank gets hung up every third or fourth rotation when spinning it by hand. Does this mean that bearing is gone?. If so is there any way to replace just the bearing or do you need to buy the whole crankshaft. Has anyone else had this problem?