2007 Kawasaki KX250F

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Host of Changes Improve Engine & Chassis Performance

Kawasaki’s all-new four-stroke KX™250F rose to the top to become one of last year’s best motocross motorcycles. For 2007, Kawasaki improves the championship winning KX250F with a host of engine and chassis modifications designed to extend its performance advantage.

Refinements to Kawasaki’s highly acclaimed KX250F make it an even more potent track weapon. The newest KX250F keeps the outstanding top-end power from last year’s motorcycle, but adds a stronger pull from the bottom of its rev range.

The upgraded engine is complimented by a strengthened five-speed transmission and a revised chassis featuring increased longitudinal rigidity for lighter, quicker steering.

The new KX250F will be available in Kawasaki lime green with new colored wheel hubs, and aggressive race team graphics.

Optional parts for the KX250F include magneto rotors with different inertias, a 12-tooth countershaft sprocket, top mounting clamp for an oversized handlebar, aluminum and steel rear sprockets, solid petal brake rotors for wet races, different springs for the front fork and rear shock, manual decompression lever and cable, and a 20-inch front wheel.

Those who race their KX250F at designated events are eligible to receive support from Team Green™, Kawasaki’s amateur racing support program. Each year, Team Green provides regional support vehicles and highly trained technicians at more than 100 events, offering technical information and assistance to those who race Kawasaki products. Kawasaki also offers a comprehensive contingency program for amateur and professional riders who place well at designated events.

Features

Engine

• 249cc, liquid-cooled, four-stroke engine delivers hard-hitting power from mid- to high-rpm
• Wider powerband extends low-rpm torque and increases over-rev

Top End

• New longer, straighter airbox funnel contributes to increased low-rpm response
• Revised carb tuning to suit the engine’s modifications
• New hand polished intake ports. This extremely-smooth surface improves intake flow at every rpm
• Ultra-light thin-stem titanium valves are strengthened by thicker skirts and held by longer guides for increased durability
• Special valve seat material helps prevent wear on the titanium valves
• K-TRIC digital microcomputer controlled ignition system with coil on plug “stick” ignition to save weight and improve performance
• Revised ignition timing improves top-end and over-rev
• Revised piston crown contributes to improved power at high-rpm
• New, looser-fitting piston ring with reduced tension for lower friction

Bottom End

• Crankshaft is surface-hardened for maximum rigidity
• Twin oil pumps ensure proper lubrication and oil scavenging for optimum performance
• Lightweight magnesium clutch, generator and cylinder head covers

Cooling

• New 20mm taller right-side radiator offers increased cooling capacity
• High-capacity Denso radiators are designed to offer superior cooling in a slim profile
• Radiator features more tightly packed cores and a special fin design to deliver superior cooling efficiency

Shifting

• An all-new 5-speed transmission with thicker gears offers improved shifting and increased durability
• New shift drum with modifications to the ratchet mechanism for more positive shifting
• New ball bearing shift shaft improves shifter feel
• New stiffer clutch springs (up roughly 20%) give a more direct feel at the lever
• Teflon lined clutch cable provides smooth action and clutch feel
• Five-speed transmission dogs are beefier to match the engine’s increased power
• Shift drum features new cam for improved shifting feel

Frame

• All-aluminum perimeter frame features composite structure, utilizing forged, extruded and cast /components
• Revised frame stiffness works with new front fork tuning for lighter steering and quicker response both on the ground and in the air
• The slim profile of the frame, two-piece radiator shrouds that leave the upper frame spars exposed, and careful design of the remaining bodywork make the KX™250F feel light and narrow beneath the rider
• New works-style aluminum skid plate for added protection

Front Suspension

• New sub springs and revised valving for the Showa twin-chamber fork offer a more progressive response and increased bottoming resistance for lighter, quicker handling and superior suspension action
• Showa twin-chamber fork keeps oil and air in separate chambers for stable damping performance during long motos

Rear Suspension

• New shock spring and revised valving for improved suspension action
• A new rear shock damping adjustment needle allows more precise tuning of the rear suspension
• Alloy swingarm uses cast front section, tapered hydroformed spars and forged chain pullers; the tapered spars are shaped to match the balance of flex and rigidity required of the aluminum frame
• New “sprocket-style” chain roller helps smooth engine braking by reducing drive lash

Brakes

• Revised front brake master cylinder hose joint allows more lever position adjustment
• Front and rear brakes utilize petal discs, helping to reduce overall weight
• Petal discs help to clean the brake pads for more efficient braking performance

Wheels

• Stronger rear rim is laced to a rib-less rear hub with new spoke design that helps reduce unsprung weight

From the Cockpit

• Renthal aluminum handlebar is ultra-strong and reduces overall weight
• Short-length grips feature a special pattern to reduce vibration transmitted from the bars to the rider
• Particular attention was paid to the body work underneath the seat to improve the rider‘s grip on the chassis when standing

New Styling

• New graphics and seat cover have aggressive style that emulates Kawasaki’s race bikes
• Number plates now feature graphical highlights for a bolder appearance
• New colored surface treatment on wheel hubs and engine covers

Options

• Different inertia magneto rotors
• 12-tooth countershaft sprocket
• Top handlebar clamp for an oversized bar
• Aluminum and steel rear sprockets with optional tooth sizes
• Solid petal brake rotors for wet racing conditions
• Optional springs for the front fork and rear shock
• Manual decompression lever and cable
• 20-inch front wheel