I have a cub cadet model# 2185, after i use it about 3 times it throws the belt and when it does it gets wedged between the pully and the tension bar and rips it, i can't keep replaceing these belts its getting very exspensive. Thetension pully is either plastic or fiberglass, it's not steel like the rest of the pully's. I can't fiqure out why it keeps throwing belts. Please help walt

Hi,
Two things are the most common culprits. They have different symptoms that usually occur with each. The first is a pivot point on the tensioning arm/pulley that is not completely free. Clean and lube the pivot. The symptom will generally have the belt not slapping around a lot, but the arm may seem to move sluggishly.
The second will be evident if the belt does slap around quite a bit. This usually means that the "V" in one of the pulleys has "opened" up allowing the belt to ride deeper into the pulley at one point and then be "pushed" outward after it passes that point. It is solved by slow and careful inspection to find the guilty item.
Peace,
Clarke