Introduced last year with AMA SuperSport competition in mind, the NINJA® ZX-6RR sport motorcycle returns to the 2004 Kawasaki lineup with upgrades to the engine and powertrain for even higher on-track performance.
With feedback from Kawasaki factory roadracers Tony Meiring and Tommy Hayden, both of whom compete aboard NINJA ZX-6RR sportbikes in AMA Supersport roadracing, several modifications have been made to the middleweight NINJA, including new cams, larger intake valves, a revised intake system and new gear ratios for the six-speed transmission.
The ZX-6RR engine is a liquid-cooled, DOHV, 16-valve, 599cc, four cylinder, four-stroke engine that delivers performance worthy of AMA Supersport competition. To give racers and sportbike enthusiasts even more power, Kawasaki engineers changed the shape of the combustion chambers, redesigned the piston crowns and added molybdenum coating to the skirts to reduce friction and mechanical loss. In conjunction with these changes, intake ports are smaller to further increase induction velocity, intake valves are 0.5mm larger for better breathing at all rpm and camshaft profiles have been changed to produce more lift. Gear ratios for the oil pump have also been changed to reduce mechanical loss, contributing to the engine's high-revving nature.
