we tried everything . finally checked the last thing possible as suggested by local racers . we put the piston at top dead center and removed the back plate and as suspected by the local racers the back bottom of the piston has a chunk missing causing the motor to lean . the piece was ground up by the motor causing other internal problems . we really liked the power and smoothness of the b6 . we ran the b5 tonight , it ran great as always. great motors we must have just got a bad one . would still recommend the b6 as a top choice . Thanks for all the suggestions you guys are a great help .