My 1984 60hp Johnson runs great, but when I turn the key off it continues to run. I have to pull both spark plug wires off (It will still run on 1 wire) or disconnect the fuel line and let it run out of gas. If I pull the emergency stop switch, it still runs. Checked the wiring on the key switch. all OK. The red/black wire has 12 V when key is on, 0 V when it is off. I believe this is what is supposed to shut the motor off. Never heard of a motor that wont quit.