I'm not a farmer, but I've been running tractors since I was 4, and I don't mean lawn tractors. I have a 1942 Farm-all model A in my garage that I'm trying to restore to look new, it was the first tractor I ever ran, it has a crank start and it's entire electrical system consists of a paper clip on the side of the distributor that when pushed against the metal distributor casing will short it out to kill the engine.