Motorcycle Repair: confusing spark problem., complete fuel system, motorcycle engine

Question
Hi, i have a chinese (xingyue) 260cc quad bike.it is seven months old and basically a motorcycle engine set up (auto).
The problem i have is.....the engine will start and run for about 30 seconds then it will die. if you try and restart it straight away, there is no spark at the plug. If you leave it for a min or so, it will start again and run for another 30 seconds or so. I have fitted a new coil,plug, h.t. lead, surpressor cap and C.D.I unit. I have removed and cleaned the complete fuel system and air filter also. the only parts i have not swapped are the rectifier and the ignition coils (which are on  order). It has totaly confused me!! hope you can help.
thanks' Andy C.

Answer
Check the wire(s) that tells the ATV it is
in forward or reverse.
This switch does not let you rev the engine
when changing the F/R selector.

The wires could be pinched or the switch faulty.
Also try disconnecting the kill switch temporarily.
Check for any relays or ignition switch problems.