I can believe 12.8 volts.... Maybe your other meter has a bad battery. On many meters the symptom of a near dead internal battery is measuring voltages way too high.

1.3 ohms is not right on the trigger wire resistance to ground. On a lot of DC powered CDI quads the kill switch shorts the trigger line to ground to stop the engine (1.3 ohms though a lot of wire and switch contacts is the same as shorted to ground). With the trigger line shorted to ground you will not get spark.

We need to find out if you have a kill switch problem or is the short inside the stator. Look at the color of the wire for the trigger pin at the CDI. Find the same color wire in the wiring harness where it connects to the stator. Disconnect the stator from the wiring harness and measure the trigger pin resistance looking into the stator to ground. Do you see something 150 ohms now? If so then you have kill switch problems or a wiring short to ground. If you still se 1.3 ohms then there is a problem inside the stator.

BTW, it was very clever of you to get the greek letter omega (Ω) into your post . I'd have never thought of that...

 

Not sure if I understand, pretty much a newbie at this. So the wire for the trigger pin is yellow. I followed it back to a connector at the rear of the bike and unplugged it. I measure the resistance from the CDI "connector" the other connector I took apart and got 0.8Ω. That's with the multimeter at the 200Ω setting?

Thanks for your help and patience.

Regards,

dmand310

 

The trigger signal comes from a small pickup coil mounted outside the flywheel and inside the engine. It drives the CDI trigger input pin which is what tells the CDI it is time to fire the spark plug.

So what you want to look for are wires coming out of the engine side cover. Also coming out of the same hole will be the AC battery charge power which goes over to the the voltage regulator.

Unplug the connector at the wires going into the engine cover. Find the pin that connects to the trigger wire (yellow) and measure that pin's resistance to ground looking into the engine (not the main wiring harness). You should see 150 ohms or so.

What the above test does is determine whether the short to ground is inside the engine, or outside the engine. We already know that it is not in the CDI because you measured the trigger wiring with the CDI unplugged.

If the short in inside the engine then you will need to take off the engine cover and look further. If it is outside the engine then we need to look at kill switches and wiring.

 

Just to be sure...

Make sure that you are really measuring the trigger wire from the CDI connector in the wiring harness, and not the wire going to the ignition coil. Remember that when you unplug the CDI and flip the harness connector over the pins are mirror imaged from the picture of the CDI posted earlier.

 

So I found the wires coming out of the engine. Followed the wires and unplugged the connector. So I measured the resistance, connector to engine "yellow wire" and got 1.3Ω.

 

So it's looks as if the problem is at the kill switch on the handlebars. If I crank over the engine and play with that switch, the plug finally sparks. Just not able to hold the switch at the exact spot all the time for the plug to keep on sparking.

Now my question is how can I fix this switch?

Thanks,

 

I think you misunderstood the previous test (I hope so anyway). Did you measure 1.3 ohms to ground when measuring the short trigger wire disappearing into the engine, or the trigger wire going back into the wiring harness. You wanted to be measuring the trigger wire going into the engine.

If you were measuring the wiring harness side instead of the wire going into the engine, and wiggling the left handlebar switch fixes the problem then you're almost there. Look at the wires coming out of the wiring harness at the left handlebar kill switch. Do you see a yellow wire there? Try disconnecting it. If this yellow wire is the trigger signal from the stator, and the spark is killed by shorting this wire to ground at the left handlebar switch, then disconnecting this wire at the switch connector will disable the handlebar kill function. The ignition switch will still work to kill spark when you turn off the ignition.

If that solves the problem then you can look for a replacement handlebar switch.

 

I took the kill switch apart and only found a brown and black wire attached to it. So i followed those wires and found that the yellow wire from the CID connects to the brown one.

So I went ahead and unplugged the yellow one, not getting a spark. I then tried the black wire instead but still nothing. I even tried both wires off.

Now if I rub both wires together I get a spark, but if I hold them together
no spark ?

 

Most quads have an integrated switch assembly on the left handlebar which include headlights, high beams, kill switch, and start button. Yours has only two wires?

It is also unusual for different color wires in the wiring harness to be tied together. Normally any one color on a quad is reserved for one function, and all the wires of the same color are tied together. For example, black with a white stripe on many quads is a kill switch wire. Black with a red stripe is often AC Ignition power. It is not common for a brown wire to tie to a yellow wire. Does this look like it was hacked, or done at the factory?

But there is a very important caveat to wire colors: This applies *only* to the wire colors in the main wiring harness. The generic plug in accessories that attach to the main wiring harness (such as ignition switches, handlebar switches, starter solenoids, tail lights, etc) are off the shelf purchased part from who-knows-where. The wire colors in the pigtails from accesories are meaningless. Just assume they are all white, because there is no information in the pigtail wire colors. What is important is the color of the wire that they connect to in the main wiring harness.

Do you really have a yellow wire in the main wiring harness connected to a brown wire in the main wiring harness tied together?

I think you have lost focus here. You measured 1.3 ohms to ground on the the trigger wire input to the CDI. That is 100% completely wrong.
This what I would be concentrating on. Why do you have 1.3 ohms? It is not the CDI because the wiring measured 1.3 ohms with the CDI disconnected. You never reported back whether the 1.3 ohms is inside the engine cover (stator) or still in the wiring harness. This is important info. I would do this test. It is simple, and may shed some light on the problem. At the very least it will eliminate the stator, and we can then focus on wiring problems.

Again, concentrate on the 1.3 ohms to ground on the trigger wire. Unplug stuff till the 1.3 ohm short goes away on the trigger wire in the wiring harness. Verify that you have 150 ohms or so to ground looking into the stator.

The trigger wire is normally driven with a carefully timed AC signal from the stator. It requires the voltage to go up and down to trigger the CDI. You don't get spark when you short two unknown wires together. You don't get spark when you don't short the wires together. But you do get spark when you "brush" the wires together? Sounds like you are connecting two unrelated wires together....

Everyone (including me) who does electrical tests does things wrong, and based on those wrong assumptions go down long blind alleys. Recheck your measurements often, and don't be afraid to say so and back up if what you said before isn't true anymore. Backing up and going different a direction is normal in electronics.