[427sharpe]

Either your battery cables are too small (I always suggest 00 gage welding cable) or your ground is insufficient. Make sure that you main ground (the batt neg) is fully contacted--no paint, and to the frame (I have seen this cable run to the crossbar for the rollbar that had painted surfaces where it hit the frame!) and I would suggest running 2 ground straps (both 00) from the motor to the frame, and from a starter bolt to the frame. This is a redundant feature that will keep you from being stranded if one ground works loose!