| Attribute | Specification |
|---|---|
| Model Series | PE05A/E |
| Production Years | 2002–Present |
| Engine Oil | SAE 10W-30 JASO MA (1.0 L) |
| Front Tire | 80/100-21 51M |
| Rear Tire | 120/80-19 63M |
| Spark Plug | NGK IFR8H11 / NGK SILMAR9A9S |
| Battery | HY85S |
Engineering Legacy: The Unicam Innovation
The Honda CRF 450 R debuted in 2002 as a paradigm-shifting machine, effectively ending the dominance of the CR250R two-stroke. Its most significant engineering highlight is the Unicam single-overhead-camshaft (SOHC) cylinder head. By utilizing a single cam to actuate both intake valves directly and exhaust valves via a forked roller rocker arm, Honda achieved the high-RPM performance of a DOHC system with the weight and compactness of an SOHC layout—a design philosophy that continues to define the PE05 platform today.
Technical Performance Analysis
The PE05A/E chassis is engineered for maximum mass centralization. The transition from the early twin-spar aluminum frames to the current refined lateral-rigidity versions has allowed the CRF 450 R to maintain its reputation as the fastest-turning bike in the 450cc class. The power delivery is characterized by an immediate, aggressive bottom-end hit, managed by sophisticated PGM-FI fuel injection systems in later iterations.
Maintenance Guide & Critical Components
Lubrication System
For the CRF 450 R, oil is the lifeblood of the high-strung Unicam engine. We recommend SAE 10W-30 JASO MA. The 1.0-liter capacity must be monitored strictly, as the high-compression piston and high-lift cam generate significant heat. Frequent changes (every 7.5 to 15 hours depending on track conditions) are essential to prevent premature wear on the titanium valves.
Traction & Handling
The PE05 series utilizes a standard motocross wheel pairing: an 80/100-21 front and a 120/80-19 rear. To ensure the precise cornering Honda is known for, maintain a tire pressure of 1.0 bar (15 psi) for both ends. This provides the optimal contact patch for intermediate terrain while protecting the rims from square-edge impacts.
Electrical & Ignition
Reliable starting is facilitated by the HY85S battery in modern electric-start models. For the ignition system, the NGK IFR8H11 (or the SILMAR9A9S for newer iterations) is the factory-specified iridium plug. These plugs are designed to withstand the extreme cylinder pressures of the 450cc four-stroke without fouling.
MotoSpecsLab Verdict
The Honda CRF 450 R (PE05A/E) remains a benchmark for motocross engineering. It demands a rigorous maintenance schedule but rewards the rider with unparalleled agility and a power-to-weight ratio that remains at the top of its class. Adhering to the technical specifications outlined above is vital for preserving the longevity of this high-performance racing instrument.
Frequently Asked Questions
Q: What is the oil capacity of the CRF 450 R?
A: The engine requires 1.0 Liter of SAE 10W-30 JASO MA oil.
Q: Which spark plug should I use?
A: Depending on the specific year within the PE05 range, use either the NGK IFR8H11 or NGK SILMAR9A9S.