I own a 1993 bobcat 743b with 3 cylinder kubota diesel. I went to start it a few days ago and when I turned the key I heard the solenoid kick in but no crank. I cycled the key 5 or 6 times and got it to crank but then it would not stop cranking even with key off and out. I had to hustle up and remove the battery cable to get it to stop cranking. Put a new starter and solenoid plus a new ignition switch knowing for sure it was going to fix it. It did not. As soon as I hook the battery up the starter starts turning over, key off. Any ideas. Machine had been running great a month before.