Thanks for your replies. Yes, it took me that much money to figure out it was not just bad starters. I've had a pro look at it, and he concluded like me it was a bad starter. I have tested my current starter with jumpers after removing it from the tractor, and there was no sound or motion. There was a spark at the + battery terminal when I disconnected the jumper, so I'm guessing the solanoid is shorted out(?). I've checked all wiring, and replaced battery, battery cable & key switch. Clutch safety switch quit, and I wired around it. More money spent. I have never tried fixing the starter myself, but have taken it into a shop.
@jaxs , if the bendix got locked, could that somehow cause a higher than rated current in the solanoid?
Here's another lead - the starter seems very rusty on the inside, as is the ring gear. Tractor has always been stored in a shed, and not used all that much. Condensation?
Another wierdness with this tractor is that the oil seems very thin, like the 10W30 I put into it got mixed with a lighter weight oil or transmission fluid. Does not appear to be mixed with radiator fluid, as there is no separation after the tractor has been sitting. The oil pressure light comes on soon after it starts - but this could be a bad pressure sensor.
