This guy has a problem with his ground said that the wire burned up all the way through the wiring harness and to the battery ,i never heard of this. So what would be a posible problem and solution to this.He did say he replace all that wire and now it wont start turns over no fire.to me it might need a magneto but I'm not familer with these tpes of bikes.He wants to sale it but i need to find out what this is first if it is going to be more of a head ache than i need but price is right sooo. thanks Jim

 

I had that problem on my Jetmoto 200 or 250.. Turned out all the ground wires went to one location and were tied into a small wire.. I made a couple more ground points and used heavier wire, and have been ok..

 

The ground wire burning up is just plain bad design, yet this same design mistake is copied on just about every quad I see. If you look at the negative battery post you'll probably see a big fat wire that goes over and get bolted to the engine somewhere. You'll also see a smaller wire that feeds other grounded stuff on the quad.

If something happens to the big fat ground return wire (like a bad. loose, or corroded connection), then when you attempt to start the quad the very large starter return current cannot return through the heavy wire. So it goes back through the little ground wire. It drops a lot of voltage, which stalls the starter motor, which makes it draw even more current. The ground wires burn up.

Note how the very large current in the ground wire is not fused. The positive battery voltage (and current) goes down the big fat red wire to the starter motor (bypassing the fuse). The starter return current comes back through the little ground wires which cannot handle that large amount of current.

The solution for this problem is to cut off that little ground return wire at the negative battery post and screw it down to the engine somewhere. Then the only return path back to the battery is through the big heavy gauge wire. If something happens to it the current can't get back period. Nothing works, but nothing burns either.

Another possible cause for burning ground wires is if the heavy gauge wire on the battery negative terminal goes to a screw lug on the quad frame instead of the engine. The starter motor return current passes to the engine. If the engine doesn't have good electrical connection to the frame then the starter return current goes through little ground wires instead (like through the little ground wire coming out of the stator). Engines are often mounted to the frame on rubber grommets, so a good connection isn't always guaranteed.

As far as not starting. have you checked to see if there is spark? Maybe that is what you meant by "no fire", but that can also mean the engine just isn't starting .

 

Mine had the fat wire connected to the thin wire...