Have a 1998 zr 600 that after it warms up it won't shut off. The key or the shutoff on the handle bar wont kill the moter. While its idoling it will start to run ruff and wont shut off then the idol comes back up and the switches start to work.
i had a similar problem with my 99 zr700 once. it would start and run and idle fine but it wouldnt shut off with the key or teather or kill switch. i had to pop both plug wires off to kill it. it turned out that under the plastic shrouding around the base of the bars where your teather and key and choke mount there is a plug that connects the teather and key to the rest of the electronics and if this gets unplugged it will start and run with no key or teather at all. mine had come just loose enough to let this happen so i would check that too.