| Specification | Value |
|---|---|
| Production Years | 2016 – 2018 |
| Engine Oil | 10W-40 JASO MA (0.7 L) |
| Front Tire | 90/90-21 54M |
| Rear Tire | 130/90-18 69M |
| Tire Pressure (F/R) | 1.0 bar (15 psi) / 1.0 bar (15 psi) |
| Battery | YTZ7S |
| Spark Plug | NGK LMAR8G |
The 2016 launch of the CJ19W/2GC8 generation marked a revolutionary shift for the Yamaha WR 450 F. It was the first iteration to fully inherit the “Reverse Cylinder” architecture from the YZ450F motocrosser. By slanting the cylinder rearward and placing the intake at the front, Yamaha engineers achieved a level of mass centralization previously unseen in the enduro segment, significantly reducing the gyroscopic effect of the engine for superior flickability in tight technical terrain.
Technical Review: Performance and Architecture
At the heart of the CJ19W is a 449cc liquid-cooled DOHC engine. Unlike its predecessors, this generation features a 44mm Keihin throttle body and a revised ECU specifically tuned for enduro applications, offering a wider powerband and smoother low-end torque. The chassis utilizes a bilateral beam aluminum frame, which provides the necessary rigidity for high-speed desert sections while maintaining enough flex for rocky single-track.
The suspension package is a standout feature, utilizing the KYB® Air-Oil Separate (AOS) forks. These are widely considered the gold standard in conventional spring forks, providing consistent damping performance without the complexity of air-fork systems found on many competitors of the same era.
Maintenance Guide & Essential Data
To maintain the high-performance standards of the WR 450 F, strict adherence to technical specifications is required. The engine’s compact design means oil volume is critical; it requires exactly 0.7 liters of 10W-40 JASO MA oil. Due to the high-revving nature of the reverse-head engine, regular oil changes are recommended every 500-1,000 km depending on usage intensity.
Electrical and Ignition
The ignition system relies on the NGK LMAR8G spark plug. This long-reach plug is essential for the deep combustion chamber of the DOHC head. Electrical reliability is handled by the YTZ7S battery, which provides the high cold-cranking amps (CCA) necessary for the electric starter system, especially in cold-start enduro conditions.
Chassis and Traction
For optimal off-road performance, the factory recommends a tire pressure of 1.0 bar (15 psi) for both the 21-inch front and 18-inch rear wheels. This pressure provides the ideal balance between rim protection and footprint expansion for maximum traction. The tire sizing (90/90-21 front and 130/90-18 rear) is standard for FIM-regulated enduro events.
Frequently Asked Questions
What makes the CJ19W model different from previous WR450Fs?
The CJ19W (2016-2018) introduced the fuel-injected, rear-slanted engine design and the KYB SSS suspension, moving away from the older 5-valve engine architecture.
Can I use synthetic oil?
Yes, provided it meets the 10W-40 JASO MA specification to ensure proper clutch operation, as the WR 450 F uses a wet clutch system.