| Specification | Value |
|---|---|
| Model / Year | Yamaha WR 450 F GP / 2018 |
| Engine Oil | 10W-40 Yamalube 4-S (0.68 L) |
| Tire Size (F/R) | 90/90-21 / 130/90-18 |
| Tire Pressure (F/R) | 1.0 bar (15 psi) / 1.0 bar (15 psi) |
| Spark Plug | NGK LMAR8G |
| Battery | YTZ7S |
Engineering Highlight: The 2018 Yamaha WR 450 F GP stands as a pinnacle of Yamaha’s ‘Mass Centralization’ philosophy. Unlike traditional enduro engines, the WR450FGP features a unique rearward-slanted cylinder and a front-mounted intake system. This configuration allows the fuel tank to be positioned centrally under the seat, significantly lowering the center of gravity and providing the 450cc beast with the flickability of a 250cc machine.
Technical Review
The WR450FGP/18 is not merely a trail bike; it is a competition-derived enduro weapon. Based heavily on the YZ450F motocrosser, the GP edition incorporates specialized ECU mapping and an enduro-specific cooling system. The 449cc liquid-cooled DOHC engine is tuned for linear torque delivery, essential for navigating technical climbs where traction is paramount.
The chassis utilizes a bilateral beam aluminum frame, which provides the necessary rigidity for high-speed desert runs while maintaining enough flex to absorb the chatter of rocky single-track trails. The 2018 GP model’s suspension—specifically the KYB® air-oil separate (AOS) front forks—remains a gold standard in the industry for its plush initial stroke and bottoming resistance.
Maintenance Guide
Engine Lubrication
To maintain the high-revving integrity of the WR450FGP, we recommend 10W-40 Yamalube 4-S. This oil meets the API SG and JASO MA standards required for the integrated wet clutch system. The oil capacity for a standard change is 0.68 Liters. Given the small oil volume and high performance of this engine, MotoSpecsLab recommends frequent intervals, especially under racing conditions.
Tires and Traction
The GP edition is optimized for off-road performance with a 90/90-21 front and a 130/90-18 rear tire. For technical enduro use, maintaining a pressure of 1.0 bar (15 psi) provides an ideal balance between rim protection and footprint expansion. If running heavy-duty tubes or mousses, adjustments may be necessary based on terrain density.
Electrical & Ignition
Reliable starting is handled by the YTZ7S battery. For the ignition system, the NGK LMAR8G spark plug is specified. This long-reach plug is critical for the unique combustion chamber geometry of the slanted-head engine; ensure the gap is checked to factory specifications before installation.
Frequently Asked Questions
Q: Can I use synthetic oil in the WR450FGP/18?
A: Yes, provided it meets JASO MA specifications to ensure the wet clutch does not slip.
Q: Why is the oil capacity so low (0.68 L)?
A: The WR450F uses a dry-sump lubrication system designed to minimize engine size and prevent oil aeration during extreme maneuvers. This requires more frequent monitoring of oil levels.