My Grandson's Chinese quad has some wiring problems. It ran until my son unplugged the tether to check it and hasn't done anything since. I've tried jumpering the tether but that didn't help. I also found the ground wire to the starter housing was bad and replaced that. Now the lights work properly and it cranks over but it seems like there's no spark. It has a 110 cc Honda or Honda clone engine. Where would one look for a wiring diagram for the ignition?

 

There are many different wiring diagrams, unless you know the make of Quad you probably won't get one. Did you try with the tether wires disconnected? Some work by stopping the engine when the two wires are joined. Take the plug out, connect the lead and lay it on the head to check if you have a spark. With all that trying to start you could have "wet the plug."