I will definately pull the prop and check the balance, I know it was balanced when it went on, I balance the hubs also. The spinner might be a little out of balance as it has been chewed up by a starter a little bit. All the engine mount bolts are snug and I went ahead and put new fuel lines on and added more padding to the tank. I dont see anything obvious. I hate problems like this, it had been running so well. Thanks