Thanks to the riding of James Stewart (KX450F), Ben Townley (KX250F/Lites East) and Ryan Villopoto (KX250F/Lites West), Kawasaki dominated AMA Supercross racing in 2007, capturing all three titles for the first time. The bike on which Stewart so convincingly won 13 of 16 rounds was the KX450F. The 450cc 4-stroke motocrosser had only debuted the year before, but it was already a champion in its second year. Key specifications came from the base machine, which featured a liquid-cooled DOHC engine with titanium parts, and an aluminium frame, with machine setup done by KMC (Kawasaki Motors Corp., U.S.A.).