A little over a year ago, I bought a used BMW from a reputable group that reconditions them. After a test ride, while the bike was idling, I was going to flip the kill switch and the guy says, "Oh no. Don't do that." I didn't think anything of it. However, a little while ago I did accidentally hit the kill switch and, to my surprise, the bike kept on idling beautifully. The only thing the kill switch would kill is a bug that it hit at 50 or more mph!
Today I got into the wiring and found that either the PO or the reconditioner had soldered a jumper across the 3 wires going into the connector that then went to the switch on the right handlebar. 2 of them did join in the connector, so no problem. but the 3rd was supposed to go through the switch to be connected. I unsoldered their jumper, re-wrapped the wires and guess what? The kill switch actually does what it is supposed to!