My '88 is about same way. While cranking, moving key from on to off, it tries to start as key goes thru the half way mark between on & off. Does same thing moving kill switch same way. Creates a momentary spike but don't keep running. Was going to get ignition switch but beings kill switch does same, it must be one of the other components(coil or cdi)? Wondering, what is the "hall sensor" suggested below?