Key Features

• An updated Launch Control System controlled through the Power Tuner App optimizes launches when the gate drops.
• New for 2026, an industry-first ECU lock function prevents theft and unauthorized engine start-up via a password-required lock.
•  A forged piston features a bridge-box design for maximized strength with minimal weight.
• Intake ports, cam profiles, high-strength connecting rod and optimized crank combine to produce potent high-rpm power.
• A more efficient intake path and revised ECU settings result in better top-end performance and improved over-rev character.
• A redesigned aluminum bilateral beam frame is tuned to provide the perfect balance of stability and cornering performance.
• Fully adjustable Speed Sensitive KYB® fork delivers exceptional balance between handling and bump absorption.

• A Lighter, Slimmer Class-Dominating GNCC® Racer

  Based on the championship-winning YZ250F, a lighter, more compact chassis offers improved agility and handling feel in tight, technical terrain, along with better ergos and a more comfortable riding position for less fatigue over greater distances. Yamaha’s revolutionary front-intake, rear-exhaust, liquid-cooled, DOHC 4-stroke power plant is paired to a wide ratio six-speed transmission for enhanced cross country performance, making the new 2025 YZ250FX ready for grueling GNCC® or Hare Scramble competitions straight out of the box.

  Advanced 250cc Four-Stroke Engine

  The compact, powerful YZ250FX engine includes all the same race-developed technologies of the championship-winning YZ250F, tuned for cross country performance. Featuring a high-spec piston, aggressive cam profiles and forward positioned intake cylinder head layout, the YZ250FX's advanced four-stroke engine is known for its broad, useable powerband and class-leading low-end and mid-range torque. New for 2025, a more efficient intake path and revised ECU settings results in even more mid- to high-end power. The cam chain has also been redesigned for improved durability.

  All-New Aluminum Bilateral Beam Frame

  A completely redesigned aluminum bilateral beam frame based on the class-dominating YZ250F motocross model provides just the right amount of strength and flex for the perfect balance of stability and cornering performance. The result is a better handling machine with lighter feel, more agility and increased traction, allowing the rider to charge corners with greater confidence.

  Class-Leading Suspension

  Fully adjustable KYB® coil spring-type fork with speed-sensitive damping delivers exceptional balance between handling and bump absorption for championship-winning performance. New for 2025, the fork now includes hand-adjustable knob for toolless compression adjustment. Linkage-type rear suspension features a KYB® shock with revised settings to provide less pitch on corner entry/exit and improved stability.

  High Performance Braking System

  The high performance braking system provides exceptional stopping power and control through high-spec componentry, including a rigid Nissin front caliper with larger diameter pistons, aggressive brake pad compound and a 270mm front rotor. The rear brake gets a lightweight Nissin rear caliper and hanger with a 240mm rear rotor to reduce unsprung weight. The rear brake line has also been revised for improved feel.

  Innovative Yamaha Power Tuner App

  Yamaha’s industry-leading Power Tuner App puts the flexibility and precision tunability of the GYTR® Power Tuner into your smartphone. Make fueling and ignition timing changes on the app, then instantly upload them to your bike for ultimate track-side tuning. Now even more user-friendly, new features include an intuitive “Simple Tuning” slide bar for engine mapping, new three-level Traction Control and updated Launch Control tuning, a new lap timer, along with helpful engine and suspension tuning guides. Best of all, it's free-of-charge.

  Slimmer Body & Improved Ergos

  The new 2025 YZ250FX features a slimmer, flatter body design for improved control, including a slimmer fuel tank, a 15mm lower airbox and 50mm narrower radiator shrouds for easier rider movement and cornering performance. The rider triangle is also improved with increased legroom between the seat and foot pegs for greater rider comfort.

  Cross Country Features

  With the electric starting system, a 2.16-gallon fuel tank, wide-ratio six-speed transmission, rugged plastic skid plate, 18-inch rear wheel, sealed drive chain and high performance Dunlop® Geomax MX33 tires, the YZ250FX is ready to win right out of the box. 

  New Traction Control & Launch Control

  The all-new Traction Control System communicates wheel slip to the ECU, tuning the engine to maintain ideal rear wheel traction. Three levels can be selected: HIGH, LOW or OFF. The updated Launch Control System now features an rpm limiter which can be adjusted in 500 rpm increments between 6,000 rpm and 14,000 rpm for optimized launches when the gate drops. Both systems are controlled through the Yamaha Power Tuner App.

  New Switchgear 

  A new handlebar-mounted multi-function switch allows simple on-the-fly selection between two preloaded engine maps with the push of a button.  Maps are loaded and configured with the Power Tuner App.

  Revised Suspension Settings

  Class leading, fully adjustable KYB® coil spring-type fork with speed-sensitive damping delivers exceptional balance between handling and bump absorption for championship-winning performance. New for 2025, the fork now includes hand-adjustable knob for easy compression adjustments, and revised suspension settings improve bump reaction to deliver an exceptional balance between cornering performance and high-speed stability. Linkage-type rear suspension features a KYB® shock with revised settings to provide less pitch on corner entry/exit for improved stability.

ENGINE

Advanced 250cc Four-Stroke Engine

The YZ250FX's liquid-cooled, DOHC 4-valve, fuel-injected powerplant features a forward-positioned straight downdraft intake with symmetrical intake ports, high-spec piston and aggressive cam profiles. Developed for victories in the highly competitive GNCC® and Hare Scrambles race series, the advanced four-stroke engine is known for its broad, useable powerband and strong low-end and mid-range torque. New for 2025, a more efficient intake path and revised ECU settings results in even more mid- to high-end power.

Piston, Rod & Crankshaft Balance

The high-spec forged piston features a bridge-box design for maximized strength with minimal weight. The piston, rings and DLC-coated piston pin, along with the offset cylinder configuration, all reduce friction loss. Intake ports, cam profiles, high-strength connecting rod, optimized crank and counter-balancer all work together to produce potent high-rpm power with user-friendly delivery and exceptional reliability. New for 2025, a redesigned cam chain improves durability.

Advanced Fuel Injection

The adjustable fuel injection system uses a 44mm Mikuni® throttle body, fed by a high-pressure electric fuel pump, to inject fuel through a 12-hole Denso® injector. This ensures optimum fuel atomization and air/fuel calibration for excellent rideability in a wide range of conditions.

Innovative Yamaha Power Tuner App

The free-of-charge 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 electronics system, the app allows owners to adjust air/fuel mixture and ignition timing to tune engine character for track conditions, log track set-up information, and monitor a range of data such as maintenance and system diagnosis, engine run time and more. For the 2025 YZ250FX, the app has been revised to be more user-friendly. New features include an intuitive “Simple Tuning” slide bar for engine mapping, new three-level Traction Control and updated Launch Control tuning, a new lap timer, along with helpful engine and suspension tuning guides.

Adjustable Engine Maps

New handlebar-mounted switch allows on-the-fly selection between two preloaded engine maps with the push of a button, making it easy to make immediate adjustments to changing track or weather conditions. Maps are loaded and configured within the Power Tuner App. Pre-loaded maps include one for fast, aggressive high-traction conditions and one with a smoother engine character for extreme, low-traction conditions.

Six-Speed Gearbox

A six-speed transmission is used to ensure the right gear is available for the wide variety of terrain found in cross country racing. Updated gearing ratios and a heavy-duty, large-diameter 15 plate clutch bring enhanced durability in the extreme conditions of a three-hour GNCC® race.

New Air Intake

A new, optimized intake path draws air from under the side covers and seat more efficiently, resulting in a boost in mid- to high-rpm performance and improved over-rev characteristics. The redesign also allows radiator shrouds to be slimmer and the airbox cover to be lower and more narrow.

Wraparound Rear-Positioned Exhaust Layout

An innovative exhaust pipe design improves mass centralization and power 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.

Mass-Centralized Electric Starter System

The YZ250FX features a compact, centrally-mounted electric starter system to minimize restart delays mid-race and add convenience everywhere else. Powered by a high-capacity lightweight four-cell lithium-ion battery, the system adds minimal weight.

CHASSIS/SUSPENSION

All-New Aluminum Bilateral Beam Frame

A completely redesigned aluminum bilateral beam frame based on the class-dominating YZ250F motocross model provides just the right amount of strength and flex for the perfect balance of stability and cornering performance. The result is a better handling machine with lighter feel, more agility and increased traction, allowing the rider to charge corners with greater confidence.

Class-Leading Suspension

Fully adjustable KYB® coil spring-type fork with speed-sensitive damping delivers exceptional balance between handling and bump absorption for championship-winning performance. New for 2025, the fork now includes hand-adjustable knob for easy compression adjustments, and revised suspension settings improve bump reaction to deliver an exceptional balance between cornering performance and high-speed stability. Linkage-type rear suspension features a KYB® shock with revised settings to provide less pitch on corner entry/exit for improved stability.

High Performance Braking System

The high performance braking system provides exceptional stopping power and control through high-spec componentry, including a rigid Nissin front caliper with larger diameter pistons, aggressive brake pad compound and a 270mm front rotor. The rear brake gets a lightweight Nissin rear caliper and hanger with a 240mm rear rotor to reduce unsprung weight.

Compact Body & Seat Design

Adopting the aggressive body design of the YZ250F, the new 2025 YZ250FX features a slimmer, flatter body design for improved control, including a slimmer fuel tank, a 15mm lower airbox and 50mm narrower radiator shrouds for easier rider movement and cornering performance. The rider triangle is also improved with increased legroom between the seat and foot pegs for greater rider comfort.

Enhanced Mass-Centralization

The compact engine, wraparound exhaust and fuel tank are strategically positioned to enhance mass centralization for a lightweight handling feeling on the track. The wide 55mm foot pegs provide added control and comfort.

Strong, Lightweight Wheels

Careful computer-aided refinement of each wheel’s cross-sectional profile shaves valuable weight without sacrificing durability. Further reducing weight, a lighter rear wheel hub is adopted while the axle diameter has been increased from 22mm to 25mm. The spokes have also been changed from a 2-cross arrangement to a 3-cross one, improving impact absorption and overall feel.

Purpose-Built Tires

Premium Dunlop® Geomax MX33 tires maximize traction while delivering excellent durability.

ADDITIONAL FEATURES

Sharp, Durable New Generation Graphics

To match the aggressive next generation YZ styling, sharp new competition-inspired graphics highlight the YZ250FX's unmatched racing pedigree. Premium graphics are embedded to provide excellent durability and scratch resistance.

Simplified Servicing

Sleek air cleaner cover provides tool-free access to the air filter, positioned at the front of the bike to avoid roost from the rear wheel.

Practical Touches

Quick-adjust clutch, wide 55mm platform foot pegs, four-position rubber-mounted handlebar clamps, aluminum handlebars and a side stand come standard for added rider convenience. The YZ250FX is also pre-wired for an optional radiator fan for the most grueling conditions.

Cross Country Features

The YZ250FX is ready for cross country competition straight out of the box with its electric starting system, 2.16-gallon fuel tank, wide-ratio six-speed transmission, rugged plastic skid plate, 18-inch rear wheel, sealed drive chain and high performance Dunlop® Geomax MX33 tires. Additional new features for 2025 include larger fork protectors, water-resistant PVC handlebar pad, a seamless seat cover design and updated multi-function switchgear.