I have my friends 1998 xc 600 and the kill switch and key do not shut it off.we looked for bad wires coming out of the motor and was wondering if I discount the single black wire coming up should I be able to ground that wire so it will kill the motor.the kill switch was the only thing working after last ride but now that's not working ether anyone had this problem and if so what did you come up with.we have been throw all the wire connections and testing the wires just if there happened to be a bad wire but cant seem to find one.next thing to do is to take flywheel off and look for bad wire or ground under that,any help would be appreciated.Thanks