How to fit a lanyard kill switch?

[dirtydog]

I want to fit a lanyard kill switch to our PW50.
From what I can see of the switch I've got is its essentially a press to make button, will the cap is on its making the circuit, pull the cap off and it breaks the circuit.
Now my first thought was to wire it in series to the kill switch on the switch gear but after a couple of tests I don't think that's going to work without bypassing the start and run part of the switch. On the PW you have a 3 position switch, Off, run and start. If I unplug all of the wires coming from the switch gear it will start but is kind of in gear so could runaway if given a few too many revs.

This is the complete wiring diagram for the bike


As said, my original thought was to disconnect the black/red wire from the switch gear and connect the lanyard into there but it doesn't kill the engine.

Would it work if I connected the lanyard switch to the 12v feed to the coil so with the cap on its making the circuit, pull the cap off it cuts the 12v to the coil?

[andrewsmith]

DD

You tried wiring it through the Red from the ignition, that looks like a constant 12v when running

[dirtydog]

With the bike running you can completely unplug the connectors to the switch gear it will keep running

[dirtydog]

Ha ha ha just noticed one of the wire colour keys at be top there "Ch:Chocolate"

[andrewsmith]

Rules that out

Inline with the Ignition coil should stop it or from the Magneto to the CDI

The 'B ' ground wire, shown to the left of the coil and spark plug is what grounds out your magneto, which is what you have to do to shut off a magneto ignition. You need a pull-on switch that grounds the B/R, just like what happens when you close the ignition switch.

Just thinking, you could use your switch to remove the ground from the low tension circuit of the coil. That would stop too.

You may be able to glean some info from the wiring instructions here http://www.3built.com/support.asp
I may be wrong but you might need to splice the switch into the black/red wire from the ignition switch.

It's a magneto ignition. There's no battery. They've used magneto ignitions on airplanes since way back when, because they keep producing electricity and sparks as long as they are spinning. They are shut down by grounding them out. My lawnmower has magneto ignition and is shut down by grounding it out.The wire that does this on an airplane ignition is called the 'P' lead.
The 'P' lead in the wiring diagram shown is the B wire leading to ground.
Interrupting the ground to the coil will stop current flow though the coil, killing the spark. Interrupting the B wire to ground, well, it's already interrupted when the ignition is on, so interrupting it again won't do anything.

[timwilky]

Personally I break the circuit between the CDI and the coil and insert the lanyard switch there.