YFZ 450R, Yamaha Sport ATV: The YFZ450R is the most technologically advanced sport ATV on the market today. It combines a high-tech, quick-revving, titanium-valved, 449cc fuel-injected engine with a lightweight, professional-caliber cast aluminum/steel chassis. The power and chassis combination makes for a championship-winning machine time and time again. The YFZ450R is motocross ready. The weldless frame is designed from lightweight aluminum, with a tension-steel bottom frame that lets the engine sit lower for excellent mass centralization. Suspension components and settings reduce weight while providing light, sharp handling and rider comfort.