Why Does the Belt Keep Coming off My Riding Mower

The drive belt may come off a riding mower because it is damaged or loose. … If broken or worn, the belt can break while the engine runs, and it can fly off at a great velocity, which is highly dangerous. Check the belt for looseness, cracks, fraying or separation from the rest of the assembly, and replace if necessary.

How do I know if my lawn mower pulley is bad?

If a pulley is badly worn, it can cause a bad vibration from the cutting deck on your lawn tractor. To check all your pulleys, start by removing the mower deck. Next, remove the mandrel covers and belt, then check all the pulleys for play and roughness when spinning.

How do you adjust a tensioner pulley?

Turn the adjustment bolt on the side, top or bottom of the pulley counterclockwise with the ratchet and socket until the accessory belt is loose enough to remove. Tighten the tensioner pulley by turning the adjustment bolt clockwise with the ratchet and socket until the belt is tight.