This engine is a very mild mannered engine - you couldnt inflict any damage on the conrod if it wasnt crashed alot. I bet its a manufacturing defect.
Ive been using mine for a long time and much more frequently than you have, with a PSPEC pipe at over 15K rpm. (with omega 5%)
Its my favorite, non-problematic engine. It never cut out in the air or the ground. knock on wood
