Chassis / Suspension

• ADVANCED ALUMINUM FRAME: The YZ250F’s compact frame refines the instinctive handling that makes this Yamaha one of the best handling machines in the class. Large upper frame bracing improves rigidity and durability. The wider rear frame spars, and the YZ250F-specific engine mounts centralize mass for the best possible balance of bump absorption, stiffness and feeling of grip.
• COMPACT BODY AND SEAT DESIGN: The YZ250F utilizes compact bodywork from tip to tail, including a narrow fuel tank specifically designed for motocross demands. In addition to shaving weight, the body design provides more comfortable knee grip and control feel, with a seat shaped to give the rider additional room to move aboard the machine.
• ENHANCED MASS-CENTRALIZATION: The engine, aluminum muffler and compact fuel tank are positioned close to the machine's center of mass. This layout contributes to centralized mass for a lightweight handling feeling on the track. The wide 55mm foot pegs help lower the rider's center of gravity for enhanced machine balance, control and rider comfort.
• 270MM FRONT BRAKE: 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.
• CLASS-LEADING SUSPENSION: Industry-leading, fully adjustable KYB® coil spring-type fork with speed-sensitive damping provides exceptional balance between handling and bump absorption for race-winning handling performance. The linkage-type rear suspension features a KYB® shock with revised damping characteristics to match the chassis.
• STRONG, LIGHTWEIGHT WHEELS: Careful computer-aided refinement of each wheel’s cross-sectional profile shaves valuable weight without sacrificing durability.

Engine

• INNOVATIVE AND UPGRADED ENGINE: The liquid-cooled, DOHC 4-valve, fuel-injected engine features a forward-positioned straight downdraft intake with symmetrical intake and exhaust ports. For 2021, the engine has been updated with cylinder head featuring a air intake system, an improved intake port shape, exhaust camshaft profile, and an updated ECU—all to produce stronger mid- to top-end power and increased peak power, while retaining its class-leading low-end torque.
• EXCLUSIVE POWER TUNER APP: The free of charge and industry-exclusive Yamaha Power Tuner app brings the power of the GYTR Power Tuner to your iOS® or Android® device. Using wireless connectivity to talk to the bike’s onboard CAN-bus network, the app allows owners to adjust air/fuel mixture and ignition timing maps to tune engine performance for track conditions, record race log information and monitor a range of data such as maintenance and system diagnosis, engine run time and more.
• ADJUSTABLE ENGINE MAPS: Two-mode adjustable engine mapping allows the rider to adjust engine character with the push of a button, making it easy to tune the YZ250F for changing track or weather conditions.
• ELECTRIC STARTER SYSTEM: The YZ250F features a compact electric starter system that minimizes restart delays on track and adds convenience everywhere else. Powered by a high-capacity and ultra-lightweight, four-cell lithium-ion battery, the system adds minimal weight.
• PISTON, ROD AND CRANKSHAFT BALANCE: 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.
• ADVANCED FUEL INJECTION: The adjustable fuel injection system uses a 44mm throttle body, fed by a high-pressure electric fuel pump, that injects fuel through a 12-hole Denso® injector. This ensures optimum fuel atomization and air/fuel calibration for excellent rideability in a wide range of riding conditions.
• WRAPAROUND REAR-POSITIONED EXHAUST LAYOUT: An innovative exhaust pipe design improves mass centralization and power development characteristics. This layout moves the rear end of the exhaust pipe farther forward and positions the muffler closer to the bike’s center of mass.
• DURABLE TRANSMISSION: The transmission gears, dogs and shift mechanisms are designed to smooth gear changes and improve durability under the heavy demands of motocross racing. The YZ250F also features a large-diameter clutch to boost reliability even further under high-heat conditions.

New For 2021

• ALL-NEW CYLINDER HEAD: The YZ250F's already potent motor was treated to a host of refinements, including an all-new cylinder head with an improved intake port shape, new exhaust camshaft profile, a new silencer, and an updated ECU and more—to produce stronger mid- to top-end power and increased peak power, while retaining its class-leading low-end torque.
• ALL-NEW INTAKE: New air box lid intake ducts have been added for increased air flow with a new high flow air filter, air cleaner boot featuring a new shape for increased flow and a larger diameter throttle body joint.
• REVISED BILATERAL FRAME: The YZ250F aluminum frame features all-new flex characteristics that give riders the ultimate combination of precise cornering performance and handling stability. By tuning the rigidity balance of the chassis with changes to the lateral beams and engine cradle tube thickness as well as engine mounts, top triple clamp and front axle, the 2021 YZ250F takes rider confidence to new levels.
• NEW SUSPENSION SETTINGS: The 2021 YZ250F features revised damping front and rear tuned in concert with the updated chassis to improve cornering performance, traction, and bump absorption. With smoother chassis movement, the rider is able to make the most of the engine's exceptional power with greater confidence.
• NEW BRAKING SYSTEMS: A new, more rigid front caliper and compact rear caliper work with new pads and discs to boost brake feel and controllability while the new 240mm rear brake rotor dissipates heat more efficiently, for a more consistent racing performance.
• DURABILITY ENHANCEMENTS: The crank case, cam chain and tensioner, waterpump, clutch basket, and the third, fourth and fifth transmission gears have all been refined to enhance overall durability.

Other Features

• ADJUSTABLE HANDLEBAR MOUNTS: The 4-position adjustable handlebar mounts are rubber-mounted to improve comfort and reduce handlebar vibration while the alloy handlebar centralizes overall mass.
• EMBEDDED GRAPHICS: Yamaha’s unique embedded graphics are built into the bodywork for extended durability, resisting both peeling and damage.
• RACE-WINNING DETAILS: The YZ250F boasts top-spec details including 1-1/8” aluminum tapered handlebars, wide 55mm foot pegs, a quick-adjust clutch perch, stylish blue rims and gold chain.
• SIMPLIFIED SERVICING: Sleek air cleaner cover provides toolless access to the air filter, positioned at the front of the bike to avoid roost from the rear wheel.

Top Features

• ADVANCED 250CC FOUR-STROKE: The YZ250F™ is ready to roost the competition with race-winning features never before seen in the 250cc class.
• POWER TUNER APP: Yamaha’s free of charge and industry-exclusive Power Tuner app puts the flexibility and precision tunability of the GYTR® Power Tuner into your smartphone. Make fueling and ignition timing changes instantly and upload them to the bike for ultimate track-side tuning.
• ELECTRIC STARTER SYSTEM: Utilizing a compact starter motor and ultra-lightweight lithium battery, the YZ250F brings the convenience of push-button starting to the racetrack for effortless restarts under pressure and relaxed riding when the clock isn’t ticking.
• ADVANCED ENGINE DESIGN: Featuring a high-spec piston, aggressive cam profiles, cylinder geometry and more, Yamaha’s reversed cylinder head layout works to give YZ250F riders the best balance of high-rpm power with a broad, useable powerband.
• TUNED ALUMINUM FRAME: Yamaha’s bilateral beam frame features main spars, engine mounts and mounting position that are designed to centralize mass and provide an ideal balance between cornering feel and straight-line rigidity.
• CLASS-LEADING SUSPENSION: Yamaha's spring-type forks with refined, speed-sensitive damping give industry-leading suspension performance straight out of the box.