If your talking about the pull tether type , there is no reason why it wouldn't work as a kill switch , though if your trying to use it as a theft deterrent , the main issue would be that all someone has to do is wedge something in between the 2 spring loaded balls and the bike will start , so it won't do much in the way of protecting you from theft , you would be better off hiding a switch inside the airbox that you can use to do the same thing , if you want it so when you fall off it kills the bike , that's a different story and it will work fine ...
