Correct, I was wondering if you hand hand start tractors and were using a pto gen set. I have a couple old AC tractors with hand start and am restoring a buzz saw for the smaller C
Nope. Engines. Those then run the PTO generators. Generators need something to turn them. I have vehicles with engines that can be started with simply cranks, in addition to old style diesels without electronics.
FWIW the 2 streams bordering my property could be used to turn paddles, which would in turn turn a generator.