I have just bought a 2011 Fuxin 110cc quad. The previous owner said it was not charging the battery and gave me a new stator with the quad. I replaced the carby as it was not working properly and had it running by jump starting it. I put on the new stator and then had no spark. I then put the old stator back in and still have no spark.
It has a 5 pin CDi and I have followed the testing procedure on these forums.
Results are:


Method 1) Unplug the CDI and remove the kill switch pin in the CDI connector on the wiring harness. The pin is held in with a spring tab on the pin itself. You'll have to probe into the connector and push this tab in order to extract the pin. Plug the CDI back in (kill switch wire dangling) and see if you have spark. No Spark

Method 2) Unplug the CDI. Turn on the ignition switch and set all kill switches to the run position. Use a meter to measure resistance in of the kill switch pin in the wiring harness connector to engine/frame ground. If the reistance is infinite on the 100K ohm scale then your kill switches/kill switch wiring are OK. If you measure zero ohms then you have a kill switch/wiring issue. Infinite on 100k scale

The other inputs your CDI needs to make spark are AC Ignition Power, and the Trigger signal. Do the following:

1) Unplug the CDI. In the wiring connector measure the resistance of the AC Ignition Power pin to the Ground pin. You should see 400 ohms or so. What do you measure? 533 ohms

2) Measure the resistance of the Timing/trigger pin to the ground pin. You should measure 150 ohms or so. What do you measure? 141 ohms

3) Leave the CDI unplugged. Set your meter to measure AC volts on the 100 volt scale. Measure the voltage on the AC Ignition Power pin to the ground pin while cranking the engine. You should see 40 to 80 volts AC while the engine is cranking. What do you measure? 48 V

4) Set your meter to measure AC volts on the lowest scale you have. Ideally this would be 2 volts but many meters don't go down this low. In that case use the lowest scale you have. Measure the voltage on the Timing Trigger pin to the Ground pin while cranking the engine. You should 0.2 t0 0.4 volts AC. What do you measure? .2 v

Now for measuring the output side of the CDI:

A) Leave the CDI unplugged. In the CDI wiring connector measure the resistance of the Ignition Coil pin to the ground pin. You should measure less than 1 ohm (but not zero ohms). What do you measure? .9 ohms

B) Plug the CDI back in. Set your meter to measure AC volts on the 20 volt scale. Set all kill switches to the run position. Crank the engine while measuring the voltage on the Igntition Coil pin to ground. Poke through the insulation of the wire if you can't probe the connector. 0 volts.

I have tried 3 different CDI units and get the same results on all. Also unplugged remote module and tether kill switch.

I unplugged the stator and measured resistance on the trigger wire coming out of the stator to ground and got 140 ohms. All connections look to be in good condition. I inspected inside the stator housing and cleaned it.
Any other suggestions on what to try next?
It is starting to really do my head in!

 

Try wiggling wires, if it was working before Dielect grease plugs & check grounds.

Damn Chinese 4 wheelers

 

All fixed thanks guys. Not sure what it was but went down the shed this morning and was doing the cdi test again and had spark. Put it all back together and the kids have had a lot of fun on it.

 

I was having ISP problems last night and coldn't answer this. But I would have only echoed what ~Ray~ said. He was right on. All your measurements said it should be working, but it wasn't. Therefore there had to be something intermittent going on, and that is usually connection/wiring problems.

 

Thanks LynnEdwards. It must of been something like that. All good now.
Your advice on these forums is great.