Long time wrench, working on a Chinese Quad for the first time..

Friend dropped me off his kids 2008 KFX50, its seen better days, but its with me to figure out the no spark issue. I dug thru the forums and tried most everything I could think of but I am still stuck. Originally it would run for a bit and die and restart after a while, but not its totally dead. I have replaced the CDI BOX with a $20 Amazon one (Half the size), new Coil and even the Voltage Regulator as doing the Spec Tests in the Service Manual, I concluded the parts were bad, yet the brand new parts all test the same. Basically I have no voltage whatsoever at the coil with the key on or off, have nothing on the yellow wire that feeds the Choke and resistors and the Stator, nothing on the white wire, on off or cranking. I have verified that the kill switch on the bars (Oddly open when running) and the fall off tether safety is good. Spark Plug is good and I have tried a few. BAttery voltage is 13V, 13V on the black wire to the CDI box with the Key on. Stator and Pickup all test within specs in the manual to ground. I've ohmed pretty much all wires hunting for a possible break, none found all below .5 ohms continuity no high resistance anywhere or open. the single green ground ground wire at the resistors has a good ground, battery ground good, 12V at the regulator on the red wire resistors within a half ohm of spec. So right now I am totally lost where or what I am missing.. its like something isn't outputting voltage, but for the life of me I cant find it. totally strange how these are wired, how things are open to run and closed to stop, meaning half the ignition switch closes to start the bike yet opens the other half of the switch, and yes i tore open the switch to verify that's what the contacts did. So hopefully one of you experts can teach this old dog some new tricks on these Chinese Quads... I know now, id never want one...LOL!! Thanks in advance

 

May have sorted it out, apparently the dealer gave me the wrong info. apparently i need a DC CDI box as I have 12V DC at the box, not AC... even though the manual clearly keeps saying AC!!! Hopefully the new Voltage Regulator is okay.... Get another one coming from Amazon

original CDI 30400-PVA1-900

 

Got the new DC CDI still no fire then realized I needed to move wires. Moved the 12v+ to the other pin and moved the Ground and Trigger wire and it fired right off with minimal cranking. Never ridden one before but a 225 fat boy on a little kiddie quad gave a new meaning to slow. But it felt okay, no funny noises ran well up into the rpm range and did about I'm guessing 25 ish.

 

I have similar problems that you described, I also bought the AC CDI box then after reading I bought the DC CDI box, I have power running through the box now unlike when I had the AC box. Still I have no spark? Exactly what wires did you switch

 

Making me think here. Been a while. I found a schematic on Amazon that showed what each pin did. On the 2 pin connector I swapped the wire to the other pin that's the 12v+, and on the 4 block one stayed put, and the other 2 essentially rotated one set of holes. Just trace out the trigger wire from the magneto, and the other wire I believe is the trigger to the coil. I can't seem to find the diagram now, but will keep searching.

HIGH PERFORMANCE DC-CDI 5 PIN NO REV LIMIT/ UNRESTRICTED RPM GY6 4-STROKE 50- 150cc CHINESE SCOOTER MOPED TAOTAO JONWAY ROKETA ZNEN BAJA PEACE VIP BENZHOU BMS JMSTAR JCL KAZUMA TANK..
This one has a similar diagram

Also note these cheap versions seem to last a few months or so, kid already burned up the one I installed but they just
ossed a new one in and away it went again.