Same thing happened to my bike. Vibration kills the tumblers. Do you know how easy it is to hotwire a bike? Take all 3 ignition wires and splice them together and your off!!!! Highly recommend the toggle switch idea. I did it. I think it's a great safety feature as well - no one would ever expect your bike has an on/off switch. I bought my switch at an auto parts store. 2-way toggle 15 amp. Forget how I wired it. You can figure it out, just play with it. Below is the pic of where I put it, but I'm sure someone could find a better place or more creative way to do it.

 

streetfighter.... thats exactly what im wanting to do... ill break out the ole multi tester and figure it out

 

I would just buy a round security key ignition switch , It won't give you any problems with vibrations.