I have an older toro proline 36" walk behind, and I'm having trouble engaging the blades. Every time I hit the switch, the belt starts to turn, and then the engine just quits . I tried loosening the belt but that didn't seem to do anything. Other than that I really don't know what else might be wrong. If one of you guys could maybe give me an Idea of something else I might want to look at I'd appreciate it.