- Drive belt is not installed correctly. (30 Series Only, Flat side goes towards engine)
- The wrong belt is being used
- Stressing the drive system; pulling loads over the maximum load limit, climbing inclines too steep.
- Pressing the brake while accelerating (riding the brake)
- Malfunctioning driver pulley and/or driven pulley
- Brake, bearings or axle that is binding or dragging
- Pulleys improperly aligned