Amazon: ignition kill switch CNCMOTOK Wiring Loom Harness Kill Switch Ignition Coil Cdi Box Spark Plug Rebuild Kit for Kick Start Dirt Pit Bike ATV 50CC 70CC 90CC 110CC-160cc Buggy Go Kart Wire Harness. TC-Motor Wiring Loom Harness + Kill Stop Switch + Ignition Coil + AC CDI box For 50cc 70cc 90cc 110cc 125cc 140cc 150cc 160cc Engine Chinese Pit Dirt Bike. $14 $ 14. 65.[PDF] KILLSWITCH TUTORIAL AND TESTING - Scooter Doc Forum The switch comes in many variations with some turning lights off as it kills the engine. Others simply stop the engine while everything else appears normal. Many have asked why it's there in the first place. It's part of the DOT safety requirements and is analagous to the RUN/STOP switch on a motorcycle.