When going up a hill or otherwise under a load the 99 EZGO TXT golf cart will hardly move. It seems as if the motor is "freewheeling" and as it gets moving a little faster the cart will then reach normal speed. This occurs whether the cart is fully charged or run down. Batteries are 3 years old. Controller is a couple of years old, which this is the 3rd controller to be on this cart. Motor is stock and controller was replaced as a stock replacement.