2004 Kawasaki KX250

2004 Kawasaki KX250 – Refining Kawasaki’s Proven Two-Stroke Racer

The 2004 Kawasaki KX250 was primarily an evolutionary update to the substantially revised 2003 machine rather than another new generation. Kawasaki retained the established 249cc two-stroke engine, steel perimeter chassis and long-travel Kayaba suspension while continuing to refine a package designed for serious motocross competition.

Its liquid-cooled engine used a 66.4 mm bore and 72.0 mm stroke, with reed-valve induction, a 38 mm Keihin PWK carburettor and Kawasaki's KIPS exhaust power-valve system. On surviving examples, carburettor condition and jetting are important because many KX250s have accumulated years of racing modifications and aftermarket exhaust changes. Owners troubleshooting the induction system can consult the MXOwners carburettor information and replacement options.

The chassis retained a 48 mm Kayaba inverted cartridge fork with approximately 305 mm of travel and Kawasaki's Uni-Trak rear suspension with approximately 330 mm of travel. On a twenty-year-old motocross bike, worn fork bushings, seals and suspension linkage bearings can have a greater effect on handling than clicker adjustments. The MXOwners fork oil level reference is useful when servicing the front suspension.

The KX250 continued with 21-inch front and 19-inch rear wheels carrying 80/100-21 and 110/90-19 motocross tyres. Owners comparing current replacements can use the MXOwners motorcycle tyre size guide. The 2004 KX250 represents Kawasaki continuing to polish its mature two-stroke formula at a time when four-strokes were rapidly taking over professional motocross, making it an interesting survivor from the closing years of the traditional Japanese 250cc two-stroke era.