| Feature | Specification |
|---|---|
| Production Years | 2005 – 2008 |
| Engine Oil | SAE 10W-30 Pro Honda GN4/HP4 (0.60 L) |
| Transmission Oil | SAE 10W-30 Pro Honda GN4/HP4 (0.59 L) |
| Spark Plug | NGK IFR8H11 |
| Front Tire | 80/100-21 51M (1.0 bar / 15 psi) |
| Rear Tire | 110/90-19 62M (1.0 bar / 15 psi) |
Engineering Highlight: The Fourth-Generation Twin-Spar Frame
The Honda CRF 450 R (PE07 generation) is historically significant for introducing Honda’s fourth-generation aluminum twin-spar frame. This engineering milestone achieved a delicate balance between torsional rigidity and lateral flexibility. By narrowing the frame at the rider’s knees and optimizing the engine placement, Honda engineers managed to create a 450cc machine that handled with the agility of a 250cc, effectively setting the blueprint for modern motocross geometry.
Technical Review: The Unicam Advantage
At the heart of the PE07A/K lies the Unicam four-valve engine. Unlike traditional DOHC setups, the Unicam system uses a single overhead camshaft to directly actuate the intake valves while using a forked low-friction roller rocker arm for the exhaust valves. This design reduces the overall weight of the cylinder head and lowers the center of gravity, contributing to the bike’s exceptional flickability in technical sections.
Maintenance Guide: Fluid Dynamics and Lubrication
A critical technical aspect of the CRF 450 R is its dual-sump lubrication system. Unlike many of its competitors, Honda separates the engine oil from the transmission oil. This prevents clutch debris and transmission heat from contaminating the engine oil, ensuring the piston and valve train receive the purest lubrication possible.
- Engine Oil: Requires 0.60 Liters of SAE 10W-30 (JASO MA). Change every 15 hours of competitive use.
- Transmission Oil: Requires 0.59 Liters. Separating this allows for the use of specialized friction modifiers in the transmission without affecting clutch performance.
- Ignition: The NGK IFR8H11 laser iridium plug is mandatory to ensure stable combustion at high RPMs.
Chassis and Suspension Tuning
The PE07 utilizes Showa 47mm inverted twin-chamber cartridges. For optimal performance, tire pressures should be maintained at 1.0 bar (15 psi) for both front (80/100-21) and rear (110/90-19). This pressure provides the necessary footprint for the 62M/51M rated tires to hook up on intermediate to hard-pack terrain.
Frequently Asked Questions
What is the total oil capacity?
The total capacity is approximately 1.19 liters, split between the engine (0.60L) and transmission (0.59L).
Does this model have a battery?
No, the CRF 450 R (PE07A/K) is a kick-start-only competition model and does not utilize a battery.
What is the recommended spark plug gap?
The NGK IFR8H11 comes pre-gapped, but it should be verified at 1.0-1.1mm for optimal spark propagation.