I'm working on this tractor which was brought to me non running. All the electrical wiring was shot and I've finally got the lighting system rewired. One of the complaints was that when you tried to start the engine and it didn't start, the starter would continue to turn the engine until the ground cable on the battery was disconnected. I figured I would have that corrected with the rewiring I've done, but the starter still does the same thing. I disconnected all the wiring except the positive battery cable from the solenoid and put a jumper wire to the "s" post on the solenoid--same thing. Checked the voltage on the "s" post while starter was turning the engine and had battery voltage both there and the + solenoid terminal with the jumper cable removed. I disconnected the starter connection from the solenoid and tried it again and the solenoid worked correctly. Owner tells me the solenoid has been replaced recently. I'm pulling my hair out! When the starter is removed from the tractor it works OK. I'm wondering if maybe the spring that disengages the starter drive from the ring gear is too weak to retract the drive when the engine doesn't start. The owner says that if the engine starts, the starter works normally. OK fellas, any ideas? Thanks again!!