Mower belt keeps breaking

If you are continually having this problem, I suggest you remove mowing deck, first remove battery ground for safety. Gloves on and belts removed, check pulleys and bearings by spinning pulley's by hand and see if there is any resistance or bearing noise. Next, each pulley at a time, try rocking pulley using both hands back and forth, up an down. Visually inspect inside of pulley's for rust, debris, and sharp metal slivers and edges. I also recommend using factory belts, they will last longer. Check idler pulley's same way. If all checks out good, grab upper idler arm by hand and see if it rocks back and forth while moving it up and down. This is the problem I had, my son and I remedied the idler assembly mount bolt issue by going to a stronger and larger bolt. This factory bolt is much too small and probably is on most lawn and garden tractors produced over the last several years. The factory bolt for my mower was a grade 5, 3/8" x 1 1/2" long. After careful inspection, we found the threads stretched and bolt warped. Notice the last three to five threads do not contact the square, bolt is stretched and warped. I purchased my lawn tractor from a dealer, maybe you did and maybe not, it does not matter. I contacted my tractors manufacturer by email concerning this issue, and I believe we all should when it concerns any issue's we are having with improperly functioning equipment.

http://www.lawnmowerforum.com/simpl...plicity-belts-braking-problem-resolution.html

That bolt issue wouldnt happen if you clean grass off the deck after done mowing every time.