I fixed diesels for lumber companies. Engines broke down in the woods as well as in the lumber yard. Diesels are pretty durable, but I would see loose wires, sawdust clogging the filters, and fuel leaks. It was a young man’s trade. You get tired of scrambling over logs in the rain. I invented a better fuel injector, but I wasn’t able to patent it. I could tell you who wasn’t interested in it.