Looking for advice/suggestions on my 9n. Having issues with it missing and sputtering for lack of a better description. It's been rewired. All new wires, harness, plugs, plug wires, coil, starter, etc etc. It will start after cranking for a few seconds and run ok. At the moment it has to be jumped to start. When leaving the jumper cables on the battery it'll run just fine. It purs. When I take the cables off it starts to miss and sputter but otherwise will stay running. Do I need a bigger battery? I'm using a regular car battery at the moment. Charging system seems to be ok. Thanks for your time.