2021 Yamaha YZ450FX

Rearward-Slanted Cylinder Design 
The YZ450FX’s distinct rearward-slanted cylinder design — complete with rear exhaust and forward-mounted intake system — features a cylinder head that works with the frame geometry for optimized weight distribution. Inside, the engine features a straight intake tract, aggressive cam profiles, a high-compression “box bridge” piston design with DLC-coated piston pin and more. Finally, the YZ450FX features specific ECU settings to suit the needs of cross country riders.

Electric Starter System 
The YZ450FX features a compact electric starter system to minimize restart delays on track and add convenience everywhere else. Powered by a high-capacity and ultra-lightweight four-cell lithium-ion battery, the system adds minimal weight.

Yamaha Power Tuner App 
The free of charge and industry-exclusive Yamaha-created 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 Mapping 
A handlebar-mounted map switch allows the rider to quickly select between preloaded engine maps — loaded and configured in the Power Tuner app — to account for changing track and weather conditions.

Advanced Fuel Injection 
The engine breathes through a 44mm Mikuni® throttle body fed by a high pressure electric pump to ensure optimum fuel atomization and power for a wide range of riding conditions.

Robust Transmission and Clutch 
The YZF450FX’s wide-ratio 5-speed transmission enhances cross country performance for more flexible gearing selection in open terrain.

POWER TUNER APP
puts the flexibility and precision tunability of the GYTR Power Tuner into your smartphone. Make fuelling and ignition timing changes instantly and upload them to the bike via the onboard Wi-Fi system for the ultimate in track-side tuning.

PERFORMANCE CHASSIS
The aluminum frame features all-new flex characteristics that give riders the ultimate combination of precise cornering performance, traction and bump stability. Revised front and rear suspension damping, tuned in concert with the updated chassis, improves 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.

• Yamaha Power Tuner app
• Cross-country-focused settings
• "Reversed" rearward-slanted engine design with 4-valve cylinder head (titanium valves)
• Forward-mounted fuel injection and rear-exiting "wrap around" exhaust
• Electric starting
• 5-speed, wide-ratio transmission
• Bilateral-beam aluminum frame
• YZ-based, fully adjustable KYB suspension
• 18-inch rear wheel
• Adjustable handlebar