I just got a Hobbico Avistar(with and OS .40 LA engine) from Tower Hobbies. After flying for several months on realflight, I decided i was ready to solo(dumb idea). Well, I broke in the motor about 5 tanks of gas, very very rich. I flew 8 successful flights and now my engine is very noisy. At low RPM it rattles really loud. It also has a lot of end-play in the crank. The sound goes away at higher throttle settings though. I know it is a LA with oilite bushings instead of ball bearings, is that noise normal for these engines?

Thanks,
Brandon