ORIGINAL: malicent
send back your motor, you got a bad one thats it. way better than proboat. im thinking there was a different issue here like maybe you were too lean, could have been a bad bearing, who knows but i would give aqu another shot!!!
Or over revving on the bench... If the OP is used to planes or buggies...boats are different. You can't rev up the engine more than a short blip on the shore. The motor has no load and can break a rod if you do.
Sean