The "best" method of stopping the engine has been subject to controversy; it all depends upon who you want to believe. Multiple wiring schemes can stop the engine without harming anything. Here is an excerpt from engine mounting instructions available from
www.BikeBerry.com:
Ignition Coil and Engine Kill Switch installation
A) Mount CD ignition coil on bike frame, close enough to attach coil wire to spark plug. Mount as far away
from exhaust pipe as possible to avoid heat damage to semiconductors in CDI module.
B) Attach CD ignition coil wires to same identical color coded wires coming from engine.
C) Install Engine Kill Switch: Select one of 3 kinds. A. Small handlebar type: B. Throttle kill switch: C.
Kill switch on optional twist handle clutch. Attach chosen kill switch wire to white wire coming from
engine. If switch has two wires, take one to frame grd. and one to the engine white wire.
D) Route all wires away from engine exhaust heat. Secure wires with a plastic tie straps.
*!WARNING! Operation of engine without stop or kill switch installed could result in personal injury
if an emergency stop is required! The only alternate non recommended way of killing the engine is by
releasing the clutch lever with bike brakes on and engine at slowest idle.
I will let other authors explain their wiring scheme. The above instructions work for me on two bikes. If the CD ignition semiconductors are prone to being damaged by grounding the output of the white wire (as I do), I doubt a continuing operation like BikeBerry would publish instructions to use the white wire.
Again, multiple methods successfully stop the engine without harming anything.
MikeJ