Mower Belt Not Staying On

[jbell1981]

I picked up a used Murray garden tractor with a 42" mower deck on it. I used it mow the lawn right after I got it (about 2 acres) and it seemed to work fine. A week later when I went to do it again the belt will not stay on the deck. It seems to stay on after I engage the mower but as soon as I move (either forward or reverse) the belt comes off. Any ideas on what would cause this?

[blue_healer_guy]

stretched or wrong sized belt would be my guess.

[jbell1981]

One of the times it came off it broke so I replaced it but the new belt has the same result.

[fishersofmen]

There is maybe a belt guide out of place. They can come loose or even break off. Also check the tensioner pulley and make sure it is working properly.

[delcecchi]

Are you sure you put the new belt on correctly?

[jbell1981]

There is only one logical route for the belt so I am confident it is on correctly.

The tension/idler pulley appears to be functioning correctly from what I can tell.

Perhaps it is a guide. Some of them seemed to be rubbing against the belt so I moved them back a bit but maybe they are to far off now. I will re-look at them.

[Walleyehooker]

The guide bolts should be very close to the pulley and usually need to be loosened to get the belt off. Shouldn't hurt if they rub the outside of the belt.

[Walleyehooker]

Checked my Scotts mower which is made by murray and the belt does rub on the guides but shows no sign of wear and has been on there for years. So if your belt is coming off of that pulley and can easily slip by the guides you need to adjust the guides.

[jentz]

The belt tension need adjustment along with the belt guide bolts

[jbell1981]

Thanks for the help. I re-adjusted all of the guides so they were nearly touching the belt when engaged and that seemed to solve the problem.