The Kawasaki KX250F competition motorcycle returns for 2005 with several engine and chassis updates, making this championship-winning motocross bike the envy of the competition.

And the KX250F is indeed worthy of such envy: in its first year of competition, Team Pro Circuit/Kawasaki/Chevy Trucks racer Ivan Tedesco rode this four-stroke Kawasaki to victory, clinching the 2004 AMA THQ Supercross Series 125cc Western Regional Championship.

To help keep the KX250F on the leading-edge of such exhilarating power and performance, Kawasaki engineers began by making refinements to the engine. The liquid-cooled 249cc four-stroke engine has improved low and mid-range response courtesy of a modified intake port, a straightened exhaust port, and revised ignition timing for improved top-end and over-rev performance.

To help maintain an optimal performance temperature, the radiators are 40mm longer for improved cooling efficiency, and the throttle cable is revised for smoother operation to enhance rider control of the broad four-stroke powerband.

The KX250F's quick-shifting five-speed transmission is improved with stronger third and fourth input gears, and the clutch friction plates now have fewer friction elements to provide the rider with a more direct feel. The stainless steel clutch cable and cable liner are changed for smoother operation, and a new clutch adjuster is added to the lever perch, making rider adjustments on the track quick and easy.

The KX250F chassis and suspension are also improved. The head pipe wall thickness is increased for improved handling and the 48mm inverted Kayaba forks have new, low-friction seals for smoother action. The fork mounting bolts have also been moved on the top triple clamp for easier maintenance.

The KX250F's high-performance disc brakes are stronger than ever and feature new front brake pad material for enhanced performance, while a new front brake lever provides the rider with better feedback.

Changes to rider accommodations include new footpegs that are wider and offer better grip; a new seat cover with high-grip top for sitting while cornering and smooth sides for transitioning from sitting to standing; and wider handlebar mounts to help prevent bending.

Features and Benefits

Engine

• Straighter exhaust port, and extended ribs in both the intake and exhaust ports improve low to mid-range response
• Throttle barrel utilizes new low-friction design for improved rider control and performance feedback
• Revised ignition system timing improves top-end and over-rev performance
• Rev-limiter changed to spark drop out control for smooth power drop-off and excellent over-rev characteristics
• Radiators are 40mm longer for improved cooling efficiency
• Water pump cover and oil filter cap are now separate for simplified maintenance.
• Muffler features new packing and construction for longer service and increased durability

Transmission

• Third and fourth input gears are shotpeened for improved reliability and durability
• New clutch friction plates have fewer contact pads to provide the rider with a more direct clutch feel
• Clutch springs are made from new, more durable material to resist sagging
• Clutch adjuster makes adjustments on the track quick and easy
• Clutch cable outer liner now made of Teflon for smoother clutch action

Chassis

• Head pipe wall thickness has been increased from 2.6 to 3.2mm for improved handling
• Footpegs are wider and offer better grip
• Chain guide roller now uses two bearings for greater durability

Front Suspension

• Kayaba semi-sealed, 48mm inverted cartridge forks have new low-friction seals for smoother action through the stroke range
• Fork mounting bolts have been relocated on the top triple clamp for easier maintenance and stronger mounting
• Lighter fork and rear shock mounting bolts contribute to reduced overall weight
• Width of handlebar mounts have been increased from 90 to 98mm to help prevent bending

Brakes

• Dual-piston 250mm front disc brake uses new pad material for improved performance and rider feel
• New front brake lever provides rider with better feedback

Bodywork

• New seat cover uses high-grip top for good grip when cornering and smoother sides for transitioning from sitting to standing
• More durable urethane foam improves comfort and durability

Kawasaki Options (Available Through Kawasaki Dealers)

• Aluminum and steel sprockets
• Carburetor setting parts
• Front fork and rear shock springs
• Flywheel rotors for altering the amount of engine inertia to suit riding style and track conditions
• Right handlebar-mounted lever allows manual operation of engine decompression, making it easier to clear a flooded engine
• 20-inch front wheel