1992 Yamaha G-9 engine runs great but cart does not move in forward or reverse. Tightened accelerator cable as this has been the problem in the past when the cart does not move when gas pedal is depressed but it didn't work this time. Occasionally the cart will begin to move but less than a few inches and stops. How do I verify if the clutch is the problem and needs to be replaced? If not the clutch, what else could it be?