Wow. 600 miles without coolant?!?!?! How did the engine not cease up?
Kawasaki superior engineering?
Idaho Falls, ID to Ft. Collins Colorado area. No coolant, none. When moving, airflow does do a fair amount of cooling. Issues were when accelerating from a dead stop. Engine was hot as a pistol, knock (pre-ignition?) was obvious. Easy on throttle till at speed.
Oil (Mobil-1 as I said) was quite dark and thick on my return, engine was making some strange noises. Over winter, engine dropped to the bench, oil pan removed, rod end bearings checked for scoring. There was none, seriously. Strange sounds were a valve rocker/cam issue, discovered 1-2 years later at the COG National in South Dakota. Or maybe it was at the Montrose national? Regardless, repairs done at the National.
Coolant hose burst approx 80k miles on the clock. I have 180k miles on the bike now, but haven't ridden it in 3-4 years. Two cam replacements, one row of rockers, set of clutch disks, gobs of oil/filters/brake pads/tires.
Rick