I have a 6v, 9N tractor that has a front mounted distributor 8N engine. I rebuilt the engine several years ago but have been having trouble starting it recently. Engine turns over at the normal speed but doesn't want to start. When I jump start using a 12v battery, the tractor starts right up. Figured that I had a weak spark caused by a weak battery. Old battery was putting out 6.33 volts. I replace the battery. Tractor started on its own power a few time but I'm back to having to jump it again. Could the starter be getting tired and needing rebuild/replaced? Also, how many amps should my generator be putting out. Any advice would help.