Of course the manufacture recommends tires with tubes for your bike.
I have the same bike. 1983 KZ440 LTD. My front wheel does say tubeless on it, but the rear wheel does NOT. My local dealer says to stick with tube tires and tubes, just the way it came from the factory. There is some reason whey Kawasaki did not install tubeless tires on these bikes.
Last edited by Kawasakirider; 07-30-2017 at 08:25 AM.
FWIW, the local Kaw dealer installed S11 front 90/90/19 and S11 rear 130/90/16 on mine. They're Spitfires, and I've found them to be OK. They seem sticky enough for my purposes, but I no longer ride hard and long.