Last weekend at the airfield i was flying my YS 110 Fz powered Mustang. the flight seemed completely normal and the sound was just as normal. After i landed i noticed that there were small metal particles in the oil on the wing. I showed this to some of the YS experts at my airfield and they said that i blew a bearing. So i ended missing 3 balls in the rear bearing, so it was replaced. Now i have the engine completely assembled with out the back plate and when i try to turn over the engine, it turns over just fine, but then put on the backplate and carburator the engine only turns over about half a turn then comes to a hard stop. Is the a problem with the backplate or the what? comments please.