2018 Yamaha YZ250F

2018 Yamaha YZ250F

The 2-straight MX & SX West Champ and undisputed benchmark in 250 motocross bikes.

• Engine

The liquid-cooled, DOHC 4-valve, fuel-injected engine features a forward-positioned straight downdraft intake with symmetrical intake and exhaust ports. A compact, high compression combustion chamber delivers outstanding engine character with a focus on top-end power delivery.

A flat-top forged piston features a bridge-box design for additional strength with minimal weight. The piston, rings and DLC-coated piston pin, along with the offset cylinder configuration, all reduce friction loss and contribute to quick response. The engine’s intake ports, cam profiles, high-strength connecting rod and optimized crank and counterbalancer all work together to produce potent high-rpm power with user-friendly delivery and exceptional reliability.

The adjustable fuel injection system uses a 44mm throttle body fed by a high-pressure battery-less electric fuel pump. This ensures optimum fuel atomization and air/fuel calibration for excellent rideability in a wide range of riding conditions. The system controls the volume of fuel injected and the ignition timing based on engine rpm and throttle opening, providing hesitation-free response and controllability.

• Chassis/Suspension

A Yamaha's renowned bilateral beam aluminum frame features compact overall dimensions that balance minimal weight with the strength and rigidity needed for race-winning performance. The frame's swingarm pivot section and engine mounting brackets are tuned for stability, responsiveness and sharp cornering.

The engine, aluminum muffler and fuel tank are positioned close to the machine's center of gravity. This layout contributes to centralized mass for a lightweight handling feeling on the track. The wide 55mm footpegs help lower the rider's center of gravity for improved machine balance, control and rider comfort.

A large 270mm front brake disc is the same system fitted to the YZ450F™, and uses an aggressive pad material for exceptional stopping power and braking control. Out back, a durable heat-resistant rear rotor boosts brake durability.

• Additional

Yamaha’s unique embedded graphics are built into the bodywork for extended durability, resisting both peeling and damage.

The 4-position adjustable handlebar mounts are rubber mounted to improve comfort and reduce handlebar vibration.

The YZ450F includes top-spec details, including 1-1/8” aluminum tapered handlebars, wide 55mm footpegs, a quick-adjust clutch perch, stylish black rims and gold chain.