We've got a brand new Grasshopper mower. Broke a Mule Drive Belt yesterday. Fortunately I had ordered a few spare parts and had one one the shelf. This morning, around 7:00, I met one of my guys heading back to the shop. I radioed him and he told me he broke another one. Two belts in 20 hours of operation. Tired of spending $72 a piece, I bought a few from our local industrial supplier and worked on the mower this afternoon. Put the new belt on and ran it in the shop. Started and stopped the mower deck dozens of times. I noticed that the idler pulley bounces so much on startup that the belt actually becomes slack enough for a fraction of a second that it completely leaves the drive pulley. I can see how it jumps off all the time and then gets eaten alive when it gets caught in the rest of the belts and pulleys. I am wondering if the clutch is being engaged at too high an engine RPM. But at the throttle's lowest setting, I bet the engine is still running at 2500 or 3000 RPM. It seems really high. In fact, there's not much difference between idle and full throttle. So I then tried to adjust the throttle down. The throttle plate on this carb isn't something that can be adjusted without making modifications to some push rods or springs. Not something I want to do with a new mower. Maybe it's just designed to run nearly wide open all the time. I've called the guy who sold it to us and am expecting a call back tomorrow but was hoping somebody here has seen this before.