Hi all hoping for some help here. Have a buddies Chinese ATV here that has no spark. All I know about it is it’s a Wildfire 110cc ATV. No clue on year or manufacturer.

It has a 4 pin CDI. The wire colors are black, black/yellow, blue/white, and green. I know the black wire has 12 vdc going to the CDI, green wire is ground, blue/white wire is going inside the engine (assuming to the stator), and the black/yellow wire is going to the coil.

Finally got the quad to turn over with a new starter, relay, and cleaning up the start switch on the handlebar. Replaced the coil and plug wire because the old one was broken and also put a new plug in. Got it all together and I have zero spark. Spent the last two days searching forums for some help but seems like most have 5 pin CDI’s so I haven’t been able to find much specific to this ATV.

I originally assumed I’d have 12vdc coming out of the CDI going to the coil but I’m reading now it’s AC voltage supposedly? Either way, I don’t have 12vdc to the coil. Many have mentioned checking all the kill switches but I don’t have a clue as to the location of them all.

Any help would be appreciated!!

 

You have a DC ignition set up with no kill wire, as when you turn the ignition switch off, it cuts the power to the CDI, and stops it sparking. The green wire is an earth and must be a good one, blue/white is the trigger or pulse wire providing a signal from a coil near the flywheel, once a rev, to tell the CDI when to make a spark. You have a 12v supply to the CDI but no spark, so if the earth is good, either the trigger coil isn't signalling when to spark, or the CDI is bad. The trigger coil wire should have a low AC voltage between it and earth when the engine is spun on the starter, but as CDIs are so cheap, once you have checked the live and earth, it is easiest just to fit a new 4 pin CDI and see if you now get a spark.