please help i cant figure out why my mini quad wont get spark

[jimbo85]

I have a 50cc quad that I bought my daughter i have no idea what brand it is, some kind of chinese off brand. it was runnig fine then jus tdied and now i can not get it to get spark. i tried changing the CDI and checked all the connections but still nothing. if anyone konws anything about them please let me know.

[jimbo85]

thnks

[LynnEdwards]

Most no spark problems have to do with Kill Switch issues. First make sure you don't have any kill switches activated:

1) On the left handlebar find that kill switch. Put it in the *center* position, then push it in toward the handlebar until it goes *click*. Not all quads have the 'click' in type switch, but anyone who has one of these type switches (like me) has been had by this more than once.
2) If you have a remote start module, unplug it. Then see if you have spark.
3) Check any tether corded kill switch to see that the tether plug is installed on all the way.

Then check out this link for a pretty good writeup on no spark troubleshooting.

Chinese ATV Parts - Kids ATVs - MeerKat 50cc Parts - BuyATVsOnline.com

I disagree with the above link about what to do next if the kill switch disabling tests don't help. I think there are more tests that can be done to narrow it down other than blindly changing things. But start with the kill switch stuff and then we can go from there if necessary.

[jimbo85]

i changed the the cdi and unplugged the center wire and it sparks weak for a sec then stops

[LynnEdwards]

So it is not a kill switch issue in your case. The fact that you get some spark says the wiring is all there and connected.

I can't think of any reason why the stator outputs would be good for a second or so and then quit. You've already changed the CDI. That leaves the plug and ignition coil. The ignition coil is what I'd wager.

[jimbo85]

I changed the coil and the cdi again and now i have nothing.

[LynnEdwards]

Let's recap:

1) You had weak spark for a second with the kill switch wire disconnected at the CDI.

2) You changed the ignition coil and the CDI and now you have nothing. By nothing I assume you now have no spark at all.

This is strange because changing working parts with working parts should not change the symptoms, rather it should work identically. Can you go back to the original coil and CDI and see if the weak spark symptom returns? This is really strange.

When things get strange more information is needed to sort this out. There's only a few things that are involved in making spark: The stator, CDI, Ignition coil, spark plug, and all the wiring in between. It has got to one of these, so let's proceed undaunted.

This is a pic of your CDI, right?


Disconnect the CDI and measure the voltage on the AC ignition power pin in the wiring harness to ground while cranking the engine. Be sure to set your meter on AC volts on a 200 (or so) volt scale. You should see about 80 volts AC. This voltage is what powers the CDI and provides the energy to drive the ignition coil through the CDI.

Measure the voltage on the timing trigger pin the same way. It will be much lower at about 0.2 to 0.5 volts AC. The voltage is low, but you should see something (besides zero volts). This voltage is the trigger signal that tells the CDI to take energy it has been accumulating off the power winding and dump it all at once into the igntion coil.

Report back these voltages and then we'll decide where to go from there.

[jimbo85]

yes thats it. ive changed everything except the stator and still nothing. i used my test light to check the stator and 4 of the 5 wires are hot when trying to start it. the one not hot is the ground.

[LynnEdwards]

Test lights are worthless for these type of measurements. You need a meter. They can be bought for under 10 dollars, and will give you the information you need.

A lot of problems have to do with shorts and opens in the wiring. Maybe you can change the stator too and still not have it work. Maybe one of the components you swapped in is bad also. Thats why I prefer to measure stuff instead of just bllndly changing things.

[londonderry]

I had the same problem. Try unplugging the on/off swith on the handle bar. I found mine had shorted out after I had washed the atv.

Good luck!