Killswitch Issues - '76 KZ400 Kickstart

Hello, I have a 1976 KZ400 kickstart only. I purchased a "motocross" style killswitch, and I have tried wiring it up in several ways and unfortunately it's not working.

I have the kill switch wires spliced into the power and negative wires of the coil. From my understanding this is how it's supposed to be wired, that way when the kill switch button is pressed, it completes the circuit and the power into the coil is suppose to bypass the coil and go straight to ground, correct? I have also tried wiring the ground directly to the frame (which does have a complete ground to the battery, I checked.)

PS I have checked that the killswitch does work as intended with the multimeter, and checked it across various points. I am completely stumped.

Neither of these setups are working. Am I doing this completely wrong?

Is there a problem with the factory switch?

I no longer have it.

You may want to check a wiring diagram but as far as i know power / 12V usually goes battery + to fuse to ignition switch to kill switch to ignition circuit and the usual or stock kill switch when operated just breaks that connection. Just an on/off toggle switch. .
I dont know how a motocross kill switch is supposed to work but all you want is something that is as simple as on/off. No diversion of 12 V somewhere else. The kill switch on most of these old bikes is centre on and the other 2 positions are off - disconnected.
Edi
You should not have kill switch connected to both power and negative wires to coil. Check wiring diagram

Hope that helps

k1z947060 wrote: Hello, I have a 1976 KZ400 kickstart only. I purchased a "motocross" style killswitch, and I have tried wiring it up in several ways and unfortunately it's not working.

I have the kill switch wires spliced into the power and negative wires of the coil. From my understanding this is how it's supposed to be wired, that way when the kill switch button is pressed, it completes the circuit and the power into the coil is suppose to bypass the coil and go straight to ground, correct? I have also tried wiring the ground directly to the frame (which does have a complete ground to the battery, I checked.)

PS I have checked that the killswitch does work as intended with the multimeter, and checked it across various points. I am completely stumped.

Neither of these setups are working. Am I doing this completely wrong?

Yes.
You are wiring it as a CDI or magneto ignition. The Kz uses a Kettering ignition.

On the Kz, when the ignition switch is "on", it feeds power to the kill switch. When the kill switch is in "run", it feeds power to the coil. There is another wire on the coil that goes to the points which open and close to provide the coil with a ground.

When the kill switch is in kill mode, the switch opens which interrupts the power to the coil.

If you are stuck with the motocross switch, you could wire it so that the points wire gets grounded through the kill switch. This will ground the coil current and prevent spark, but will energize the coil so you don't want to leave the ignition on very long this way.

A better idea would be to get the correct style switch.

loudhvx wrote:

k1z947060 wrote: Hello, I have a 1976 KZ400 kickstart only. I purchased a "motocross" style killswitch, and I have tried wiring it up in several ways and unfortunately it's not working.

I have the kill switch wires spliced into the power and negative wires of the coil. From my understanding this is how it's supposed to be wired, that way when the kill switch button is pressed, it completes the circuit and the power into the coil is suppose to bypass the coil and go straight to ground, correct? I have also tried wiring the ground directly to the frame (which does have a complete ground to the battery, I checked.)

PS I have checked that the killswitch does work as intended with the multimeter, and checked it across various points. I am completely stumped.

Neither of these setups are working. Am I doing this completely wrong?

Yes.
You are wiring it as a CDI or magneto ignition. The Kz uses a Kettering ignition.

On the Kz, when the ignition switch is "on", it feeds power to the kill switch. When the kill switch is in "run", it feeds power to the coil. There is another wire on the coil that goes to the points which open and close to provide the coil with a ground.

When the kill switch is in kill mode, the switch opens which interrupts the power to the coil.

If you are stuck with the motocross switch, you could wire it so that the points wire gets grounded through the kill switch. This will ground the coil current and prevent spark, but will energize the coil so you don't want to leave the ignition on very long this way.

A better idea would be to get the correct style switch.

Okay - I will get the correct style switch.

I'm trying to to understand how this works - please correct me if I'm wrong:

Stock setup - basically two on switches (ignition, stock "kill switch") - this flows constant power to the coil when both are on, which when just sitting there "on" is NOT grounded because the points open/close at very specific time and that's what grounds the coil.

When the "mx style" kill switch - I would be diverting the power from the energized coil away from the points and to a frame ground, allowing constant power flow through the coil, hence burning it up. However as soon as I release the kill switch button the current flow would stop - and it's condition would essentially be the same as factory, correct?

Regardless - I will not use it - I just want to make sure I understand how this works.

Thank you,

k1z947060 wrote: Okay - I will get the correct style switch.

I'm trying to to understand how this works - please correct me if I'm wrong:

Stock setup - basically two on switches (ignition, stock "kill switch") - this flows constant power to the coil when both are on, which when just sitting there "on" is NOT grounded because the points open/close at very specific time and that's what grounds the coil.

Yes, the two switches are simply in series to pass power to the coil. The coil is energized when the points close which provide the ground.

k1z947060 wrote: When the "mx style" kill switch - I would be diverting the power from the energized coil away from the points and to a frame ground, allowing constant power flow through the coil, hence burning it up. However as soon as I release the kill switch button the current flow would stop - and it's condition would essentially be the same as factory, correct?

Yes, if it's wired correctly.

It depends on which coil wire you connect to the mx switch.

If you connect the power wire, you would be grounding power directly to ground which should blow a fuse immediately. (That is, assuming the mx switch has a single wire and that wire gets switched to frame ground through the handle bars, and that the frame is indeed grounded to the battery. If you had spark before, and haven't removed any wires, then the engine, and thus frame, have a path to battery ground somewhere.)

If you connect the points wire to the mx switch, then you would simply be energizing the coil when you kill the bike. Since the switch prevents the coil from de-energizing, it prevents spark from happening. This will allow the bike to work, and will allow the kill switch to kill the bike, but is not a good practice as it can heat up the coil if the ignition is left on and the kill switch is left in "kill" position. (This situation can even arise with the stock wiring if you turn on the ignition switch and the points happen to be closed, and you don't start the bike. So leaving the ignition switch on whenever the bike is not running should be avoided.)

If the mx switch has multiple wires, then there are a few other possibilities.

Understand now - thank you!