Hi does anyone know much about the Kymco maxxer 90cc quads as I know this ain’t your normal cheap Chinese quads, so after someone with a bit of experience in they or know about wiring,, had no spark so replaced CDI unit as old one didn’t work,, new stator/pulser, new ignition coil and spark plug, after replacing parts had spark started up and test drove for like 2mins before stopping,, once stopped wouldn’t fire back up so took spark out to test on engine and sometimes there’s a spark and others times there isn’t and when there is a spark it looks weak to me, what could this be ????

The engine has had top end rebuild don’t know if info helps in anyway,

I’ll attach a pic of wiring diagram

Wiring diagram Kymco maxxer 90cc

 

Right, this is a decidedly weird DC CDI set up. At CDI, black is pos from ignition switch, blue/yellow, pulse signal from flywheel, This wire also goes to ignition switch and kill switch and is shorted to earth with ignition off or kill switch on. Green is earth, and the other, light green wire just jumps one pin of CDI to another. Check you are getting full 12v between the green and black. With engine spinning on starter, you should get a small AC voltage between blue/yellow and green. With CDI plugged in, you should get a decent voltage between Black/yellow and earth when engine is spun on starter. This wire goes to ignition coil. Intermittent faults are the worst to find as all may test right because the fault has gone off.

 

hi I’ve currently got the wiring loom sat on the side as I’m going to be replacing all connectors on it and check for broken wires,, on the CDI you mentioned the light green it looks like that has been removed and just bunched up with two other wires but it was like it when I brought it and it ran fine apart from smoking so done too end rebuild and whilst putting back together wires touched which blow CDI and pulser but I’ve replaced with original parts, I’ll send pic over of CDI wiring,

also my safety pull switch runs off the earth by looks and links into ignition coil, lights at front, regulator rectifier and key ignition barrel, and stop/start switch lol could I bypass any of these safety switches so I can see if any off them is causing issue ??

 

As I wrote above, the CDI needs the wires to it to be right, most important is the black from ignition, and green earth, are sending full battery 12v power, and that the pulse coil wire is OK too and not shorting to earth when it shouldn't. Also the black/yellow is properly connected to a good ignition coil. Nothing else is required for the bike to keep running once started, though the battery would slowly run down if the charging circuit wasn't also OK.

 

I’ve managed to fix it thanks for all your help I followed steps above and wasn’t getting power to ignition coil, as I was testing I knocked the CDI and seen the meter go up, so problem was rubbish connection on CDI unit 😀👍🏻