Help please txt80 rookie 2005

[Kerabo]

Can anyone offer advice please.
I have been looking at the above bike for a mate. It suddenly stopped. There is no spark. He has substituted most part with another bike but still the same. I have checked the condition of all wires from the stator to the cdi and all seems good. He fitted a new kill switch. I had the stator off and cleaned all the grunge away and refitted it. Are there any common failures?
Fitted new plug lead and plug.

A few questions please

Does the kill switch ground the stator or break the circuit?
Can I disregard all other components like fan wiring and just concentrate on the wires from the cdi to the stator.
The pickup coil on the stator shows a flow to earth but I guess this would be correct as the coil would need to earth?
I was unable to find much info on the wiring.
Any advice please.

Thanks Ken