The plunger on the fuel solenoid stays open all the time, even when the key is in off position. After I start engine, it closes. If I unhook one of the wires connected to that solenoid, the tractor will stay running all the time. I have to put the key in start position again, before it will die. Does that mean I need a new fuel solenoid???? Or can I bypass the solenoid somehow? or is it OK to run the tractor like that?