After a mile or so run down the road the other day I pulled into the drive way and my fairly new OEM belt blew up on me. The belt probably has less than 100 miles and was a Yamaha 700 (on a 660). When I tried to pull the primary sheave off I noticed that the cam plate had spun slightly to the point where the splines were on top of each other. I had to use a hammer to rotate the cam plate before I could pull the sheave off. I put a new Yamaha 660 belt back on with a cam plate off of another sheave. Has anyone heard of a belt failing this quickly or the cam plate spinning on the shaft? The belt that failed had a fairly easy life. It seems like I go through belts to often. Could there be an issue in the sheave like maybe some slight wear on something that is causing the belts to slip some and thus getting hot? I still have an extended warranty so I going to try and get new sheaves out of Yamaha but don’t know if that will happen. Any thoughts would be appreciated.