2017 Yamaha YZ450FX, PURE 450 CC X-COUNTRY RACER Designed for closed course X-Country and enduro-type racing the YZ450FX combines light, nimble handling with the power of a 450. Additional Features GYTR® POWER TUNER READY: Accessory GYTR Power Tuner lets owners adjust air/fuel mixture and ignition timing maps to match engine performance characteristics to the rider and race conditions in a matter of seconds with the push of a few buttons. REAL WORLD TOUGH FEATURES: Rugged plastic skid plate, quick-adjust clutch, aluminum handlebars and a side stand are standard for added rider convenience. SEALED O-RING CHAIN: High quality O-ring chain is tough and durable. EMBEDDED GRAPHICS: Yamaha s unique embedded graphics are built into the bodywork for extended durability, resisting both peeling and damage. Chassis / Suspension BILATERAL BEAM ALUMINUM FRAME: YZ450F-based frame offers a compact size while optimizing mass centralization. With its extensively tested assembly of aluminum forgings and extrusions complete with model-specific engine mounting, the FX frame retains legendary Yamaha handling and response. ADVANCED YZ450F FRONT FORK: Fully adjustable YZ450F-based KYB® spring-type fork with speed sensitive damping delivers precise, fade-free handling. REVISED SHOCK TUNING: The rear linkage and KYB® shock provides 11.6 inches of travel with adjusters for high- and low-speed compression damping, rebound and spring preload and features a large piggyback reservoir for excellent damping and fade resistance. 270MM FRONT BRAKE: 270mm front brake system provides exceptional stopping power and braking control. GNCC®-SPECIFIC TIRES AND WHEELS: Lightweight 21-inch front and 18-inch rear rims provide exceptional durability with enduro-specific tires. Engine CROSS COUNTRY-TUNED YZ450F POWER: YZ450F-style 449cc liquid-cooled DOHC four-stroke, with forward-positioned straight intake, delivers massive power specifically tuned for cross country racing, to challenge for race victories in the very competitive GNCC® and Hare Scrambles race series. INNOVATIVE ENGINE DESIGN: The position of the engine moves the rotational mass of the cams towards the center of the bike which allows for a straight shot, down-draft intake and straight exhaust port for ultimate performance. This also keeps the airbox up high, out of dust and mud/water. WRAPAROUND REAR POSITIONED EXHAUST LAYOUT: Lightweight YZ450F-spec exhaust system maximizes engine power while centralizing mass, thanks to the innovative wrap-around header design. ADVANCED FUEL INJECTION: The fuel injection system uses 3D mapped electronic control for the fuel and ignition timing that are optimized for cross-country racing, with a YZ450F-based 44mm throttle body. WIDE RATIO GEARING: A five-speed wide-ratio transmission is used to insure the right gear is selected for a wide variety of terrain found in cross country racing, from tight sing