| Specification | Data |
|---|---|
| Model Series | CJ26C / B2WA |
| Production Years | 2021 – 2022 |
| Engine Oil | Yamalube 4 (10W-40); API SG+, JASO MA (0.68 L) |
| Spark Plug | NGK LMAR8G |
| Battery Type | HJTZ5S-FP-I (Lithium-Ion) |
| Tire Dimensions | F: 80/100-21 51M / R: 120/80-19 63M |
| Standard Pressure | 1.0 bar (15 psi) Front & Rear |
Engineering Highlight: The Yamaha YZ 450 F (CJ26C) continues to utilize Yamaha’s revolutionary rearward-slanted cylinder design. By reversing the cylinder head and intake/exhaust ports, Yamaha achieved a direct downdraft intake and centralized the bike’s mass more effectively than any competitor in its class. This specific Monster Energy Edition brings factory-team aesthetics to a platform that pioneered smartphone-based engine tuning via the Yamaha Power Tuner App.
Technical Analysis: The CJ26C Platform
The 2021-2022 iteration of the YZ450F represents the pinnacle of Yamaha’s refined aluminum bilateral beam frame. For the Monster Energy Edition, the focus is not just on the aggressive black and blue livery but on the underlying hardware that has dominated MXGP. The engine features a high-compression piston and aggressive cam profiles, requiring precise maintenance to sustain its high-RPM performance.
Lubrication and Cooling
With a relatively small oil capacity of 0.68 liters, the YZ 450 F demands high-quality synthetic lubricants. Yamalube 4 (10W-40) is the factory recommendation, ensuring the JASO MA friction requirements are met for the wet multi-plate clutch. Given the high thermal stress of motocross, oil changes should be performed every 7.5 to 10 hours of operation under racing conditions.
Electrical & Ignition
The CJ26C utilizes the NGK LMAR8G spark plug, which is specifically designed to withstand the high combustion pressures of the 450cc four-stroke engine. Starting is handled by a lightweight HJTZ5S-FP-I lithium-ion battery, significantly reducing weight over traditional lead-acid units while providing high cranking amps for consistent starts in the heat of a moto.
Handling & Maintenance Essentials
The suspension is anchored by the industry-leading KYB SSS (Speed Sensitive System) coil spring forks. To maintain the balance of the chassis, tire pressures must be monitored closely. We recommend a baseline of 1.0 bar (15 psi) for both the 80/100-21 front and the 120/80-19 rear tires, though this may be adjusted slightly based on track density (sand vs. hardpack).
Summary for Technicians
- Valve Clearances: Should be checked every 3-5 races.
- Air Filter: Requires cleaning after every ride to protect the downdraft intake.
- Chain Tension: Maintain 50-60mm of slack to prevent binding during full rear-shock compression.
The Yamaha YZ 450 F Monster Energy Edition is more than a cosmetic package; it is a precision-engineered racing tool that requires disciplined technical oversight to remain at the front of the pack.