My 2 year old Dixie Chopper mowing performance has dropped off drastically. Recently, I noticed the mowing belt has multiple cracks, plus pieces of it were missing, operating only with a small part of the main string backing holding it together. It still mowed, fine I thought. I changed the belt, but now the belt comes off frequently, the blades bog down at the least bit of tall grass that I try to mow. The nearest dealer is no help either. This is the third belt I've had on the mower in two seasons. Is that unusual? I have just over 300 hours on the mower. Is there a diagram anywhere besides the little cheap owners manual they give out when you buy it that looks like it came off a copying machine? Those instructions are as helpful as a spoon in a row boat.