2003 Honda CRF450R

2003 Honda CRF450R - Refining Honda's New Four-Stroke Weapon

The 2003 Honda CRF450R was the second model year of Honda's new-generation four-stroke motocross machine. Unlike the landmark 2002 CRF450R that introduced the model, the 2003 bike was an evolutionary update rather than an entirely new generation. Honda retained the basic 449.4 cc engine, aluminium twin-tube chassis and five-speed transmission while refining the suspension and chassis setup after a full season of racing experience.

The liquid-cooled 449.4 cc single retained its 96.0 x 62.1 mm bore and stroke and was fed by a Keihin FCR flat-slide carburettor. Correct carburettor condition and adjustment remain particularly important on these early four-strokes, and owners dealing with worn original components can use the MXOwners carburettor replacement and reference information. The engine and five-speed gearbox use separate oil compartments, so both oils need to be checked and serviced independently.

One of the useful distinctions between the first two CRF450R model years is the suspension. For 2003, front axle travel increased to approximately 281 mm and rear wheel travel to approximately 319 mm. Owners rebuilding an original machine should therefore avoid automatically applying 2002 suspension figures to a 2003 bike. The MXOwners fork oil levels and suspension reference is useful when comparing fork service information.

The 2003 CRF450R remained a very light and powerful competition four-stroke for its era, with an aluminium frame, 21-inch front wheel and 19-inch rear wheel. Original tyre sizes were 80/100-21 front and 110/90-19 rear; the MXOwners motocross tyre size guide can help when selecting modern replacements. Today, valve-train condition, starting behaviour, cam-chain wear, oil-change history, gearbox condition and suspension-linkage bearings are among the important areas to inspect. As the second-year version of the motorcycle that helped establish Honda in the modern 450 four-stroke class, the 2003 CRF450R remains an important early CRF and an increasingly interesting machine to preserve.