Every new sporster engine I have run has needed to be cleaned out before running. The .65 I just bought had burrs in the carb and some small shavings in the crankcase left over from the mfg process. I had a .20 years ago and it was dirty also. The break in I have done with these engines is always very sloppy rich without leaning for quite some time because it would cause the engine to heat up and die anyway.