The Liquid-Cooled Engine
Of course, everyone else was on liquid-cooling anyway, and it was crucial because it meant that, as revs and heat increased, power didn't drop off.
We'll probably never see the end of air-cooled lumps, as they are still favored for naked motorcycle simplicity.
Tag: Liquid-Cooled Engine Cooling-Liquid GSX-R750 Suzuki Cooling Engine-Heat