Spark, no spark, spark

[Steve Bakken]

So Im working on my daughter's 49cc Chinese four wheeler. Was running fine then the next time she went to ride it, no start. Checked the plug, and it sparks once when you hit the starter button, then nothing while it cranks. ??? No spark i could probly figure out, but this? Any ideas?

[Macgyver55]

Does it sound like it's spinning over as fast as normal? Some of those can be very finicky about voltage. Sometimes just the cranking of the starter drops the voltage too low for it to crank fast enough to have good spark. Try jumping it with a good battery and see if it starts when it has a good voltage source. Aside from that it may be a stator problem.

[Steve Bakken]

I had jumpers hooked up to it from my v8 Durango. Spun good and fast but same symptoms. On that note, though, the headlight quit working this spring. There's current there, but the filament just emits a small glow. Hmmm

[Macgyver55]

The lighting coil is also part of the stator too. I would carefully check the harness where it comes out of the motor for any chafing or broken wires. There are tests you can do with an ohm meter to see if the stator is good or not but I'd check all the easy things first.

I seem to remember that some models have a safety kill switch (tether) that is by the rear of the seat and grab bar that kills the motor if they get too far away from you, take a look at that too.