Take a look at the record books and you’ll see that no other 250cc motocross bike in the modern four-stroke era has earned more championship titles in AMA Supercross and Motocross than the Kawasaki KX™250F. The 2014 KX250F's championship-winning technology includes a new Launch Control system, a plug-and-play adjustable ECU, Separate Function Fork (SFF), new motor mounts, revised suspension tuning and an upgraded transmission. Make no mistake, the KX250F is still the dominant player in the 250cc ranks. Ride anything else, and you’ll just be playing catch-up.
At a Glance…
• Launch Control is a first for the 250 class and increases ability to get good starts, by maximizing available traction
• Showa Separate Function Fork (SFF) provides progressive damping force and features 48mm inner fork tubes for rigidity
• Dual injector Digital Fuel Injection (DFI®) system
• High-rpm engine output extends deep into the over-rev
• High-tensile steel front engine mount plates are 29% thinner than last year’s steel plates and offer a better mix of chassis rigidity, improved feedback and superior front-end grip
• Transmission gears feature four dogs instead of three, for enhanced shift smoothness
• Shift-fork grooves are more-direct to enhance feel at the shift lever
• Counter-shaft and sprocket retainer design now uses a nut and washer instead of a clip, for a more positive sprocket –to– countershaft interface and simplified sprocket swaps
• Upgraded crankcase oil jet delivers an optimized stream of oil to the underside of the piston, for enhanced cooling
• Revised throttle body tuning improves airflow from a closed-throttle, for a smoother idle and enhanced low-end response
• Revised piston tuning in the left fork leg enhances damping performance through the initial and mid-stroke
• Revised rear shock settings provide a more comfortable “baseline” for a wide range of riders
• Grips feature shorter barrels and are made from a softer material to enhance rider comfort
High-Revving, High Performance Engine
• 249cc, liquid-cooled, four-stroke, four-valve, single-cylinder DOHC engine delivers hard-hitting power across the rpm range
• Nickel plating on the cylinder wall has a high adhesion factor for optimum durability
• Thick-stem connecting rod resists flex and enhances durability
• Upgraded crankcase oil jet delivers an optimized stream of oil to the underside of the piston, for enhanced cooling
• Thick crank web design features a balance factor on par with the factory racers to help minimize engine vibration, provide smooth power delivery and maximize performance in the mid-high rpm range
Factory-Style Launch Control System
• Launch Control is a first for the 250 class and increases ability to get good starts, by maximizing available traction
• Launch Control is activated by pushing a button on the left handlebar while stopped, in neutral, first or second gear
• Retards ignition timing in first and second gears, giving the greatest effect within the first few seconds of releasing the clutch
• Shifting into third gear automatically deactivates Launch Control Mode and returns the ignition to normal mapping
• Particularly effective when chasing the holeshot from concrete starting pads and other slippery surfaces
Digital Fuel Injection (DFI) System
• Intake tract designed to provide optimal airflow from the airbox into the combustion chamber
• Seal between air inlet port and throttle position sensor unit on the 43mm throttle body protects TPS sensor from fuel penetration
• Progressive throttle linkage for sharp and precise throttle response across entire rpm range
• Simple and efficient system: No battery, fuses or relays
• Offers easy engine starting
• Helps prevent engine hesitation after landing from jumps and other high-impact situations
Bridged Box-Bottom Piston
• Piston profile helps increase reliability compared to non-box-bottom design
• Light and strong piston shares same design as the factory racers, and a tin plating to optimize its interface with the nickel plating on the cylinder wall
• Special finish improves surface lubrication and wear resistance
• Short piston pin reduces reciprocating weight
Lightweight and Efficient Top End
• Intake valve seat material offers increased durability
• Ultra-light valves have extremely thin valve stems on par with those found in supersport machines; intake valves feature thick heads for increased strength
• Special casting method leaves the intake port surfaces extremely smooth for optimum intake efficiency across the rev range
• Silicon-coated head gasket provides excellent sealing
Stainless Steel Exhaust System
• Head pipe resonator chamber helps boost low-rpm torque
• High-volume muffler assembly features a large cross section to keep noise levels at 94 dB while retaining power production
• Durable stainless steel construction
Efficient Cooling System
• Thick radiators are strong and offer excellent resistance to mud buildup while providing superb cooling performance
• Cylinder head water jacket routes coolant to the front of the cylinder head for even cooling
Transmission and Shifting
• Transmission gears feature four dogs instead of three, for enhanced shift smoothness
• Shift-fork grooves are more-direct to enhance feel at the shift lever
• Clutch cable holder is integrated with the crankcase for accurate feel at the clutch lever
• Scavenge oil filter screen can be accessed without splitting the crankcases, facilitating easier maintenance
Quick-turning Chassis
• The KX250F’s slim and lightweight aluminum perimeter frame helps provide excellent ergonomics and handling
• Center of gravity and key dimensions such as swingarm pivot, output sprocket and rear axle locations designed to increase forward drive with minimal rear-end squat
Separate Function Fork
• 48mm Separate Function Fork (SFF) delivers firm damping response and increased ride comfort
• SFF design separates springing and damping functions for less weight, better performance, less stiction and easier adjustability compared to traditional forks
• Revised piston tuning in the left fork leg enhances damping performance through the initial and mid-stroke
• Super-hard titanium coating on the outer surface of the inner fork tubes reduces stiction and improves suspension action while also helping prevent scratches and tube damage
• Friction-reducing Kashima Coat treatment on the inside of the outer fork tubes contributes to smoother suspension action
• Wrap-around fork tube guards provide excellent protection for the inner tubes
Uni-Trak® rear suspension
• Rear shock features dual compression adjustability, allowing high-speed and low-speed damping to be tuned separately
• Features Kashima Coat on the inside cylinder wall for reduced friction and smoother suspension action
• Revised rear shock settings provide a more comfortable “baseline” for a wide range of riders
• Swingarm features tapered hydroformed spars and forged chain adjusters
• Uni-Trak® rear suspension linkage system mounts the suspension arm below the swingarm, allowing more rear suspension stroke and precise tuning
• Linkage ratios for the Uni-Trak rear suspension match rear shock damping settings to achieve maximum rear wheel traction
Rider Interface
• Bodywork components offer the rider a slim interface, making it easy for racers to feel comfortable and go fast
• Formed using a double-injection molding process, the shrouds offer a slim design
• Right side panel passageways help cool the silencer
• Flat design of the seat and tank allow freedom of movement
• Frame is wider at the ankles to offer better grip and narrows near the bend below the seat to allow a slim riding position
• Slim seat features polyurethane designed to be durable
• Seat has a slip-resistant top and side surface for good grip when seated and while standing
• 50mm wide (front-to-rear) footpegs offer superb grip and feel at the pegs
• Clutch cable boot features a large quick adjuster, making it easy for riders to adjust play in the clutch cable while on the fly
• Throttle grip has a one-piece collar that provides additional stability during throttle operation
• Grips feature shorter barrels and are made from a softer material to enhance rider comfort
Factory-style Components
• Pushrod-type front brake master cylinder and brake pad material provide strong brake force and enhanced feel
• Rear brake pad material offers powerful braking performance
• Lightweight black anodized rims are durable and look just like the factory racers
• Titanium-coated inner fork tubes minimize stiction and look great
• Front and rear petal brake discs help reduce unsprung weight, and the wave shape helps clean the brake pads for more efficient stopping performance
• Rear caliper guard protects caliper from damage
• Ribless rear hub and butted spokes reduce unsprung weight
• Renthal aluminum handlebar is standard equipment
• Blue ignition cover plugs and oil filler cap match the blue accents on the factory race bikes
• Factory-style graphics complement the KX250F’s highly tuned performance
Additional Features
• Radiator shrouds and side panels provider a slim rider interface and a nimble feel
• Embossed design on clutch cover
• High-density chain pad on top of the swingarm is more resistant to wear
• Large resin skid plate offers great protection with minimum weight
Optional Accessories
• Optional DFI Calibration Kit allows custom tuning
• Optional FI Indicator Light allows the DFI system to communicate diagnostic information
• Optional engine parts include magneto rotors with different inertias and a 12-tooth output sprocket
• Optional chassis parts include handlebar holder for a 1 1/8-inch handlebar, 46 to 50-tooth aluminum and steel rear sprockets, solid petal brake rotors, different fork and shock springs and manual decompression lever and cable