Join Date: Feb 2012
Location: Colorado Springs, CO
Air cooled bikes require airflow over the fins to keep happy. That said, keep in mind Phoenix PD still uses KZ1000s (air cooled inline 4s) as police bikes, which sit there and idle for quite a while before going WFO.
Oh and keep in mind there are plenty of I4s with air cooling, including the original supersports.
Most of the time, they went to liquid cooling not necessarily for reliability, but because liquid cooling means you can design tighter tolerances, meaning more power out of the same size engine.
E.G. My Z750...
Previous version? ZR7S made from 99-03 (In the US) 75 HP 46 ft lbs.
Same engine size...
Z750S made from 05-06 is 107 HP and 55 ft lbs...
Last edited by Wrider; 03-01-2012 at 12:36 AM.