Just bought (my first) tractor. An Iseki Landhope 160 (TU160F) 1984-86, 3 cyl diesel, 4wheel drive. Ignition switch works fine to start it (even the counter clockwise position to warm glo-plugs seems to work ok). PROBLEM IS THAT WHEN YOU SHUT IGNITION SWITCH OFF, TRACTOR KEEPS RUNNING. Only way...