Hey guys! pls help! My son's atv is driving me crazy. He was riding it one day and when he turned it off he couldn't start it again. We let it sit and then we eventually got it going. Now there wasn't any spartk. I replaced the ignition coil. nothing. Replaced the stator. now there's power to CDI. Replaced CDI and now I get one spark when I push the start button and only one spark when I release the button. thanks

 

From your description you first had no spark, then after changing a bunch of things it still isn't fixed and now the symptoms are different. That raises the possibility that a new problem has now been added to the old one. That can make things a little harder to figure out, but not impossible.

What is engine size on this quad?

Do either of these CDI's look like yours?




You said after changing the stator you now had power to the CDI. How exactly did you determine that? Most CDI's are AC powered (80 volts AC at cranking speeds). Some are 12 volt DC powered. Do you know for sure which you have? I'm just trying to figure out where the starting point should be. It is easy to figure out with some voltage measurements, which we can do if necessary.

Most no spark problems have to do with kill switches and kill switch wiring. All of this can be measured with a voltmeter. But yours doesn't sound like this because you do get a spark sometimes.

Stators can be measured for proper operation also. Besides the high voltage AC power for the CDI, there is a trigger signal that tells the CDI when to fire. In your case I'm a little suspicious about this signal on your quad. The CDI does fire with the starter motor turning on/off. Maybe the large electrical transients from the starter is triggering the CDI but the real CDI trigger signal isn't getting there. This can be measured.

First things first:

What engine size?
Do you see your CDI pictured above, and if so which is it?
Do you know for sure if your CDI is AC or DC powered?
Get yourself a voltmeter and get ready to use it.

Lets go from there....

 

The first one with the green. I need to get the volt meter. I just have never used one. I just started from the battery and replaced items that didn't have a source of power with a power checker (the light would come on). I just received a new kill switch/starter button attatchment for the handle bar. The wiring in this was corroded with strands detatched inside. Thank you so much for your help.

 

110 engine size. I don't know if it's AC or DC.

 

Lets hope the new switch works. If not, definately get that voltmeter and we can go from there.

 

applied new starter switch on handle bar with no luck. I am picking up the meter over the weekend. The last thing I haven't replaced was the voltage regulator. thank you so much for being willing to help me. My son got a taste of the track and has been bummed since his quad went down hill. His grandfather gave him his schucks special (big *** wheeled motorcycle that has a gas mower sized engine on it) to keep him occupied while I battle this beast.

 

oh ya also, the brake light bulb is burn't out. would that make a difference (I am trying to find a bulb to see if it matters but having trouble, will order online if I need another part I guess)

 

If the starter turns when you push the start button then the starter button is working. All it does is help apply power to the starter solenoid which in turn applies battery voltage to the starter motor. It has nothing to do with generating spark.

Ditto the voltage regulator. Its job is to charge the battery. It has nothing to do with generating spark.

Burned out brake lights won't affect spark either. A bad brake switch can keep the starter from turning when you push the start button, but your starter turns so that isn't an issue either.

You really need that voltmeter.

 

i've got a bmx also. similar problems; replaced ignition coil, cdi, spark plug with no luck.

my fix was a loose connection. there is a wire coming off the male plug that goes into the female connection on the cdi. i believe it is the ignition coil or ac ignition wire as labeled in the green cdi picture above. it travels to the rear of the atv to another four prong connector that plugs into a connecter with a silver key chain looking ring attached to the connector. it's just hanging their connecting the wires to each other. this connection was/is loose for me. it looks a little corroded. anyway, i cleaned it a little, bent the metal connector a little to produce a tighter fit and got spark and start. this might be your problem.