My problem started out with Kubota BX1850 not starting. I had problems with the pto safety switch so I replaced it. It started but when I turned the tractor off it wouldn't start again. Changed the battery, it started and I mowed some. Turned the tractor off, it wouldn't start again. I worked the speed control peddle back and forth, the tractor started, but now the tractor doesn't move. I'm not a mechanic. When I press the pedal in either direction I hear it engaging. The front end loader and attached brush mower are working. Any ideas on what to check to see if I can repair it myself. On a fixed budget so trying not to take it in for repairs.