Will not stop

[ToonArmy]

1997 Force 120, cannot shut it off. I've had problems with engines not starting, but this is the first time I've had one that keeps running w/ignition off. I have to disconnect the fuel line to stop the engine from running. Any suggestions ?

 

[roscoe]

Re: Will not stop

First off, don't run the gas out to kill the motor.
Your end up running the fuel lean and risk damage to the engine.


You have a wiring issue.

Either on the back of the ignition switch, or on the engine.

Start with the easy one.
Look at the back of the ignition switch.
There should be a wire attached to each of the terminals marked with an "M".

These 2 wires are connected in circuit when the switch is turned off, they ground out the ignition.

.

 

[fucawi]

Re: Will not stop

to be more accurate the two terminals marked M ( for magneto) are joined together with the key in the off positon. Grounding is not involved at the switch. I the old days they made the opening and closing of the contacts ineffective so the engine stopped . similar effect here on the electronics.

 

[eurolarva]

Re: Will not stop

Next time it wont shut off try choking it instead of running the gas out. Choking it should kill it real quick with no damage to the motor

 

[Frank Acampora]

Re: Will not stop

1997 is mercury ignition, so everything is in the wire loom. Check the switch, and also check for corrosion inside the big red (or black) connector inside the engine. Corrosion in there will prevent the capacitors in the CD unit from going to ground and stopping the engine. YES--the ignition switch does allow the capacitors to ground out instead of dumping into the coil(s). That is how the engine is stopped--no spark.
Also, use a VOM to check the wire and see if it has continuity with the switch off. One broken wire of the stop pair will also cause a run-on condition. I will leave it to someone else to jump in and tell you the specific terminals in the red connector and the wire colors.
Now, offhand, I do not remember if the 97 has a terminal boare where you couls also short the capacitors to ground. If iit does have one, look for a broken wire or again, corrosion there.