I took it to the LHS this morning after I got the engine remounted. The guy at the LHS said the same things you guys have been saying, I'm betting that the engine came loose and that what was causing it to rattle so much. He also stated that I need to balance my prop, anyone have any plans for a prop balancer I can make at home. I know they are only $20 but if I can make one for $5 I would rather do that.