Motorcycle Repair: ATV no spark problem, honda kawasaki, electronic unit

Question
I purchased a 50cc 4 stroke Chinese ATV for my two sons. Went well, but progressively, it became harder to start and the battery soon failed.

I replaced the battery and would crank OK, but would not start. Replaced the spark plug and found spark would only appear every now and again, until there was no spart at all.

I checked through the electrics as follows:
wiring - all connections OK
kill switch - works OK
ignition coil - tested OK, but replaced with new
CDI - replaced with new, but still no spark
tested stator (magneto) - appears OK - approx 48v AC from stator to the CDI
I'm not able to read any volts from the CDI to the ignition coil
Trigger (pulse) coil - reading 1.5v to CDI
Is the 48V AC from the magneto to the CDI sufficient voltage?
I'm not able to get an ohm reading for the trigger (pulse) coil as it is an electronic unit

Do you know what else I can do with this?

Any help woul dbe appreciated

regards
Greg  

Answer
Hi Greg,

I do not have any tech resources for this brand to compare your meter measurements with.

It's possible to get a new defective part. After reviewing your narrative, I suspect the pulse coil is defective or there's a grounding problem somewhere.

Depending upon the brand, you may find a service manual at "www.repairmanualclub.com"

I receive many tech questions for these import ATV's. I don't recommend purchasing these brands as there's little tech support available, they're expensive, and they seem prone to fail mechanically. Honda, Kawasaki, Suzuki, and Yamaha are recommended.

Respectfully,
Mark Shively