I have a 48" Scag belt driven WB that has gone through 4 belts on the right side this season. It doesn't really wear them out, it just stretches them to the point that the right side won't pull. I've tried treating it with belt dressing, and that seems to help for a little while but it will do it again soon after. Has anyone had this problem? Or perhaps some idea of why it is doing this? Any input would be helpful. I love this machine, it leaves a beautiful line but gets really frustrating having to replace belts or constantly stay on the left brake.