Still haven't been able to find a solid photo of the socket on the ATC style speedometer, but normal Honda one uses a socket very similar to this one. I suspect the terminals on the ends of the wire will have to be changed since they would likely be a 4mm bullet instead of 3.5mm. If anyone buys this to test, let me know if it works, or just buy one from any Kawasaki dealer for around $10 new. If the socket is right, I can fix the wiring so it's plug and play. I think it is a different bulb style, but I don't think that will effect much.
https://www.ebay.com/itm/Kawasaki-KZ...!-1:rk:34:pf:0