How do I install a kill button on my electronic ignition?

We get this question often so we decided to address it in this tech post.

The typical method of shutting of the ignition on a EI bike is with a key or toggle switch. Both of which are in the closed position during running. Switching off or opening the circuit kill power to the ignition turning off the engine.

Most ignition makers omit instructions for mounting a bar mounted kill button. There are two reasons they probably do this:

One the kill button can be a cause of faults. A corroded switch can cause all sorts of problems. Please use new electrical components. I can’t tell you how often a problem can be traced to reusing original suspect parts such as high tension wires.

Two using the wrong type of kill button can damage your ignition. Unless you understand what you are doing ask for help. We will detail this further below:

We should begin with stating there are two different ways of wiring an ignition: positive and negative earth. There is a preferred type of kill switch for each of these.

Positive earth (ground) systems: we advise installing a normally closed push switch inline on the white wire. Pushing the button opens the circuit interrupting power to the power module.

Normally Closed Cutout

Negative earth (ground) systems: we advise installing a normally open push switch on the negative side of the far coil. Pushing the button closes the circuit interrupting power to the ignition coils.

Grounding Buttons