Spark only sometimes
 

I have a 110cc qiye engine. My problem is that I am only getting spark when I hook the charger to it and charge at 40 amps and even then its not consistent. If I crank and crank and crank with the spark plug in and charger hooked up I can get it to sometimes start and it'll run which astounds me. So far I've changed the stator, cdi, whole wire harness, spark plug, handle bar kill switch, and key switch. Not sure there is anything else I can change. I've actually put a few different stators in there and they all do the same thing. This makes no sense. Could it be a grounding issue? The starter turns fine. only thing I haven't changed is the solenoid. I can't spend any more hours banging my head playing with this thing. :huh: please help!!!!!

I had something close read frustrated mechanic and frustrated part 2. no spark just the odd time with a wiring harness I built . I just got it running after 40 plus hours beatting my self up. I changed the magneto. to this day I don't get it but worked. Started right away and runs fine.
hope that helped