I have what I was told was a CPI 90 kids quad. When I bought it the guy got it started and when I got it home it ran for about 10 minutes. Now I can't start the thing.....no spark. It has 2 tether kill switches and the handlebar as well. I put a new CDI box (5 pin), new plug and still no spark. While checking all the connectors I found that the front kill switch has 1 wire disconnected. I tried plugging it into each of the 3 unused female connectors in my harness bundle......still no spark. Can I disconnect both tether kill switches to get it running or do the switches have to be working in order to get spark?
Thank you in advance,
Scott

 

I'm not familiar with that model. Is this a picture of your CDI?



If so, then pull out the kill switch wire from the CDI connector and see if you have spark. If you do then you have a kill switch problem.

Note 1: If your quad starts up with kill switch wire disconnected you will not be able shut off the quad without hooking this wire back up. And there is high voltage on this pin coming out of the CDI. If you find yourself in this situation then turn off your ignition switch, set a kill switch (handlebar or tether) and then hook that wire back up with insulated pliers.

Note 2: Kill switches on generic chinese quads work by shorting the kill switch wire on the 5 pin CDI to ground. Kill switches are disabled by unplugging them, not by shorting them.

 

It is my CDI box. If I understand you correctly after removing the center wire from my CDI and it starts (because I have a kill switch problem) turning the ignition off will not shut it down? If I have one kill switch that is faulty and I disconnect it will the others still function properly?

 

Ok. I think I got it now but one last question.....If I determine (by removing the kill wire at the CDI) that I do have spark can I disconnect the faulty kill switch and have the remaining ones work properly after reconnecting the kill wire back to the CDI?

 

Yes, if you have a generic wired chinese quad. This is because one section of the two section ignition switch *is* a kill switch. When you turn off the quad the ignition switch shorts the kill switch line to ground, killing the spark and stopping the engine. The other section of the ignition switch switches on 12 volts to the lights, and allows the starter solenoid to be activated. On a 5 wire CDI the ignition runs on its own supply coming off the stator, and not the battery.

 

Yes, kill switches are all wired in parallel, so that any one of them (when shorted) will kill the spark. So if one is disconnected, the others can still short the same line to ground and kill the spark.

 

Sorry to have to bug you again. I disconnected the middle wire from my CDI (mine is a solid green wire) and cranked the starter with the plug out.....still no spark. If I did everything correct it seems my kill switches are not the problem. I tried this with both my original CDI box and the new one. Neither changed the outcome. Any suggestions as to what should be my next step?

 

The solid green wire doesn't sound right. Green is usually ground. Black with a white stripe is the most common color for the kill switch wiring. Please check that you disconnected the correct wire. If you remove the ground to the CDI you will definately no get spark.

If the middle pin is indeed solid green, then what are the five wire colors on your CDI connector? I'm gathering info here. When things look strange I try to get as much info as I can. Does this wiring harness look like it has been hacked at all?

Disconnect the CDI and measure the AC voltage on the AC power pin to ground on the 200 volt scale while cranking the engine. What do you measure?

Set your meter to the lowest AC voltage scale it has Measure the AC voltage on the Timing Trigger pin to ground while cranking the starter. What do you measure?

 

You were correct! Further testing showed one of the kill switch connections was faulty. It didn't show when I removed the center pin (the solid green one) because mine must be a different pin location. It's now running fine. I appreciate all your help. I want to change oil now but want to verify what engine I have. Any way of determining this? I suspect it is a 70cc but not sure.
Scott