Trying to get my brothers killswitch/ignition working By FACE PLANT FOR LIFE (Read 1,365 times)

[FACE PLANT FOR LIFE]

This has been going on for quite a while now, but most of the time, my brothers killswitch and ignition do not function at all, in any combination. As if it's not grounding the CDI's spark (which is probably the scenario). But here's the weird part: If I unplug and replug in the small 2-wire (black and black/red) connection from the CDI, the bike will die, and then if I plug it back in, the killswitch and ignition will work UNTIL you raise the RPM's. Once you hit about 2000 RPM and try to kill it, it will surge down but then will come back up as if it's not grounded and it will stay like that until I unplug those wires again. If I let it sit at idle however, the killswitch and ignition will continue to work.

Weird...right?

[racerx125]

well on mine I have kill switch for key switch and kill switch and my engine kill switch stoped working and wouldn't turn off engine, turned out to be a loose wire in the connections from killswitch to harness. If I remember correctly you can find a diagram for the wires in the killswitch in this forum

[racerx125]

Here I found it might help you out as it did for me.
www.chinesescooterreference.com/jr/KillSwitch.pdf

[FACE PLANT FOR LIFE]

But in this case, both the killswitch and ignition fail to kill the engine as if the ground was completely missing, but if the ground was missing, all the other electrical systems would fail, would they not?

[Alleyoop]

No the ground on the Key and Killswitch only effect the CDI to kill the motor. All the other things on the scoot have their own ground.
Alleyoop

[FACE PLANT FOR LIFE]

Okay, well I took my multimeter and did a continuity test. I put one probe on the black wire coming from the ignition and then the other probe onto the frame of the bike, and it reads 0.00-0.01. Does that sound right?

[tvnacman]

When testing cdi's for stock I came across one the would not kill the engine . It ran just fine .

John

[FACE PLANT FOR LIFE]

It's not the CDI. We have tested several.

[Bashan]

What is the bike? Did I miss it? Please give us the engine code and bike model. The one thing that will vary is wiring configurations. However, the fact that you raise the RPMs, and therefore the voltage from the stator, smacks of the regulator/rectifier. Have you swapped that component out? Rich

[FACE PLANT FOR LIFE]

It's a 139QMB engine. It doesn't have a specific model, but it does look like the TaoTao VIP (the one with two headlights, not one). I have not yet swapped out the regulator, as I didn't think it would make a difference, but I have a few regulators I can throw around.

[Bashan]

Yeah, you're right, brain fart. OK, how about this, stator voltages? Check the red/black just for giggles too. Something is failing with increased current..very odd. The regulator might do that but it would be a stretch. Rich

[Bashan]

It's probably a bad ignition switch. The switch kills via the same mechanism as the killswitch, grounds the coil to frame. I'm not sure what the extra voltage is doing...maybe heating up a partial short. Let me go get you the ignition switch diagnostic...be right back.

[Bashan]

Here's the whole thing:

If you have the front cowling off of your scooter and the ignition switch harness is exposed, you can test your switch directly with a multi-meter instead of the tests at the CDI harness. Here is the harness on a '08 Bashan 150cc, of course your scooter may vary:

You'll note coming out of the ignition switch are a red, green, black, and the black/white killwire. Oddly, the killwire changes to a purple color on the other side of the harness, the others remain consistant.

TESTING THE RED TO BLACK WIRE FROM THE SWITCH

A red wire comes directly from the battery and the switch connects it to the black wire when in the on position to provide power to the scooter. Put one multimeter probe on the red wire, and one on the black coming from the switch, it doesn't matter which probe is placed on which wire. Test for continuity with the switch ON, you should get zero resistance and a tone which indicates a circuit:

When you turn the switch off the power circuit should open (L=no circuit):

TESTING THE GREEN TO BLACK/WHITE WIRE FROM THE SWITCH

The green ground wire connects to the killwire in the off position and grounds out the coil to stop the engine. Obviously the purple wire changes back to a black/white wire before it reaches the CDI:

Turning the switch on breaks the connection between the ground and killwire and allows the engine to run:

So two positions of the switch affect the four wires in this manner:

Switch on= red to black connection for power to the scooter; green to black/white open so kill function is off

Switch off= red to black open so no power to scooter; green to black/white connected which grounds coil at CDI and stops engine

If any of your multi-meter tests vary from this scenario, your ignition switch is bad and must be replaced.