Small Engine Troubleshooting Problems? Ask a Mechanic Now.
915020 belt 46 1/2 X 5/8-----is this the belt size you have? A narrower belt will be too long, letting the idler rub the main pulley.
All it shows is the 42 inch deck. Is this a two idler setup where the idlers go one each side of the belt, to pinch it to tighten? Have you tried rerouting the belt through the idlers.
No, I find no diagram showing the belt arrangement for the belt between engine and deck. I will opt out