Build your own kill switch for Pocketbie?
I'm currently building a vehicle with a pocket bike engine (50cc and 3.5 hp). My question is, can I attach a simple toggle switch to the cable attached to the spark plug so I can turn the engine off with the switch?
No. The cable on the spark plug is a high-voltage cable, which must and should not change. If you put it on a flip-flop, you get voltage surges and, most likely, you get a tacky.
You need a low-voltage line that controls the ignition. Normally, each ignition electronics has such a connection. Here, for example, with the name “Substitute”:
http://www.motelek.net/anderen/cdi/china_cdi/lead_replica-cdi.png
Take the little cable out of the ignition and connect it to the engine, and see it goes out!