I was mowing my CRP when I hit a rough patch, it bounced me around in the seat and the tractor quit. I tried to re-start and realized the PTO was engaged. I dis-engaged the PTO and it still won't start. I have rammed it back into the PTO several times, my seat is already by-passed. So that isn't why it quit. I've checked the hydrostatic pedal safety feature and it appears to engage... My battery is good(radio, blower, lights all work). Any ideas?