Ignition switch problem

[spy1309]

I have a 1960 Johnson 40hp and the strange thing is that I cant stop the motor from running, I did not touched the ignition switch and the wireing is the original one.
In the junction box there are 2 wires coming from the magnito, I trace them and they are connected to the 2 M poles of the switch, the continuity is perfect but when I turn of the switch the motor is still running.
I read in the forums that the switch in off position grounds the 2 M poles but in my switch there is no ground pole.
Checking with the ohmeter the switch opens and closes in off or on position the circuit betwen the 2 M poles nothing more so I tried to short the 2 magneto wires in between them but no succes the motor keeps running.
The only way to stop it is to ground one of the magneto wires with a wire to the negative battery pole.
Now as I said theres no pole for negative on the switch or room for it so it was never intended to have a negative pole at the switch so how in the world was the motor stoped before?
Any ideeas ? the seloc manual is useless.

 

[F_R]

Re: Ignition switch problem

The switch electrically connects the two M posts together in the "off" position, not connect them to any ground. SO what happens if you just connect the two blacks together? It sounds like you've tried that and it didn't kill the motor, is that right?

If connecting the two blacks together at the switch doesn't kill the motor, there is something wrong with the wires or connections. One black wire goes to one set of points. The other black goes to the other set of points via a connection on the center of the vacuum cut-out switch. The whole scheme of things is that in the switch-off positon the two sets of points are connected together, thereby shorting everything out and no more spark to the plugs.

Trace the blacks clear back to the motor and you should find the problem.

 

[Barnacle_Bill]

Re: Ignition switch problem

My manual doesn't cover 40hp but on the 50 the magneto wire goes to one of the M poles and the other goes to ground.

 

[BoatBuoy]

Re: Ignition switch problem

In the case of a CDI ignition, one wire from the power pack is grounded to kill the engine. Therefore, using the same ignition switch, one M is a ground and the other is the power pack kill wire. When the key is switched off, the CDI kill wire is connected to the ground. A little different than the magneto kill method.

 

[spy1309]

Re: Ignition switch problem

Thanks guys for the input, as FR said one black wire is from the first set of points the other one is from the second set so none of the 2 black wires is ground .
I traced them up to the vacuum cut-out switch and perfect continuity I will try to check the vacuum cut-out switch, in the manual they said that if you disconect the wires you should not have spark.
Now I see that the magneto wire from the vacuum cut-out switch goes to some ....my guess......mercury level switch placed on the acceleration lever ( the one whitch moves when you switch between slow...start....high speeds) the seloc manual leaves alot to desire they don t mention alot of very important stuff.
Basicaly I guess like FR said the engine suppose to shut down when the 2 magneto wires where shorted togheter, I did that with a wire to be closest to the source but no luck the engine is still running.
FR I forgot to mention that the wire kill metod ( grounding the magneto wires to the battery negative with a wire) does not work with both magneto wires it works only with one wire, now I don t know yet if it is the one going to the vacuum cut-out switch or the one going directly to the points set.

I have 2 work arounds in case I can t solve the problem even do I will like to fix this one .
One ideea is to install a push button switch with one lead to ground and the other one to one of the M poles of the ignition switch.
The other ideea is to remove one of the magneto wires from the switch and replace it with a ground wire.