Another gen problem

I had similar problem with a 4K onan. After taking it in and out twice and to a shop twice I fixed it myself. Took the cover off, found a square plug with multiple wires coming and going. Sorry I don't know what it would be called, about 2" square. Unplugged by gently prying open with screw driver, multiple tiny pin style connectors, very tiny so be careful. Sprayed with electrical contact cleaner, both male and female sides, plugged and unplugged multiple times to clean corrosion. Plugged back in, fired up and problem solved. Not saying this is your problem but solved mine. Generators live with corrosion due to road spray like anything else. Good luck, Don