I have three wires coming from transmission on a 125cc Chinese ATV.I don’t k ow where they go.Can someone please help me out.

 

Quite often they go nowhere. I am working on one at the moment that could do with a neutral light but hasn't got one. However, it does have wires from a gear indicator switch in the gearbox, they are left disconnected. If your bike does have a neutral light, that is where one of the wires should go. It will be the earth side, pos is fed directly to lamp from ignition switch.