Belt Auction

Why does my lawn mower keep throwing the belt?

Could a small dent on the idler pulley cause this?

Public Comments

1. Yes to the dent, possible other causes: loose or worn belt, pulleys out of alignment, wrong size belt. Bearing on one of the pulleys is going bad.
2. The dent is most likely the cause. At high speed it throws the belt off the pulley. Try straightening it out . If that doesn't work, buy a new pulley and a new belt. Your problem will probably go away.
3. Also check the bushing/bearings of all pullies and idlers. If one or two of them are wobbly, they they will need to be replaced.