2015 Kawasaki KX 250F
The record books don’t lie. Whether it’s Team Green™ amateur racing, professional AMA Supercross or Motocross, the most successful 250cc motocross bike in the four-stroke category just got even better thanks to a series of upgrades designed to maximize the performance of this already impressive motorcycle.
At a Glance…
• Revised damping settings in the Showa Separate Function Fork (SFF) provides progressive damping force and features 48mm inner fork tubes for rigidity
• Revised Uni-Trak® rear shock settings
• New 270mm “oversized” front rotor, petal-style Braking-brand rotors front/rear
• New finer-atomizing Downstream Fuel Injector and revised ECU settings
• Launch Control increases ability to get good starts, by maximizing available traction
• New Bridged-Box-Bottom piston
• New Magneto Rotor with increased inertia
• Adjustable footpegs and handlebar clamps
• Lighter subframe
• New Factory styling
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 new Bridged Box piston with short skirts and reinforced external ribs for increased strength.
• 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
• The KX250F Launch Control was a first for the 250 class and increased the rider’s 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
• New finer-atomizing Downstream Fuel Injector and revised ECU settings
• The dual injectors are fine-atomizing injectors with four holes. The upstream injector has a droplet size of 120µm, while the new downstream injector is 75µm. The finer size and wider spray pattern contributes to a stronger low- to mid-range power, improved response and quicker acceleration.
• Intake tract design provides 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
Bridged Box-Bottom Piston
• Thicker dome and reinforcing ribs increase durability
• 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
• Short header and resonator chamber enhance low-end power and provide strong top-end power
• Head pipe resonator chamber helps boost low-RPM torque
• Short high-volume muffler assists with mass centralization, makes good power, while large cross section restricts noise levels to an AMA race-legal 94dB.
• 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 for smooth shifting
• Shift-fork grooves 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
• 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
• Revised settings on the 48mm Separate Function Fork (SFF) delivers firm damping and increased ride control
• SFF design separates spring and damping functions for less weight, better performance, less stiction and easier adjustability compared to traditional forks
• 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
• Revised rear shock matches performance of the front forks
• Rear shock has dual compression adjustability, allowing high-speed and low-speed damping to be tuned separately
• Features Kashima coating on the inside cylinder wall for reduced friction and smoother suspension action
• 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
• New two-position, adjustable footpeg brackets allow rider to lower the position by 5mm, lowering the center of gravity.
• New four-position upper triple clamp with two sets of handlebar mount slots. These give the rider a choice of four bar positions, including 25mm forward, 15mm forward, standard or 10mm back to suit many sizes and styles of riders
• 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 have short barrels and are made from soft material to enhance rider comfort
• 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
• New green anodized suspension adjusters, engine oil cap and generator cover plugs like the factory race bikes
• Factory-style graphics complement the KX250F’s performance
• 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 DFI® Kawasaki Racing Software 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
- Engine: Liquid-cooled, four-stroke single with DOHC and four-valve cylinder head
- Displacement: 249cc
- Bore x stroke: 77.0 x 53.6mm
- Fuel injection: DFI® with 43mm Keihin throttle body and dual injectors
- Compression ratio: 13.8:1
- Ignition: Digital DC-CDI
- Transmission: Five-speed with wet multi-disc manual clutch
- Final drive: Chain
- Frame: Aluminum perimeter
- Rake / trail: 28.7 deg. / 5 in.
- Front suspension / wheel travel: 48mm inverted Showa SFF telescopic fork with 40-way spring preload adjustability and 22-position compression and 20-position rebound damping adjustability/ 12.4 in.
- Rear suspension / wheel travel: Uni-Trak® linkage system and Showa shock with 19-position low-speed and 4-turns high-speed compression damping, 22-position rebound damping, fully adjustable spring preload / 12.2 in.
- Front tire size: 80/100-21
- Rear tire size: 100/90-19
- Front brake: Single semi-floating 270mm petal disc with dual-piston caliper
- Rear brake: Single 240mm petal disc with single-piston caliper
- Overall length: 85.4 in.
- Overall width: 32.3 in.
- Overall height: 50 in.
- Wheelbase: 58.1 in.
- Ground clearance: 13 in.
- Seat height: 37.2 in.
- Curb weight: 233.7 lb.
- Fuel capacity: 1.61 gal.
- Color: Lime Green
- Engine Type
- Four-stroke single with DOHC and four-valve cylinder head
- Bore and Stroke
- 77.0 x 53.6mm
- Compression Ratio
- Fuel System
- DFI® with 43mm Keihin throttle body and dual injectors
- Digital DC-CDI
- Front Suspension
- 48mm inverted Showa SFF telescopic fork with 40-way spring preload adjustability and 22-position compression and 20-position rebound damping adjustability
- Front Brakes
- Single semi-floating 270mm petal disc with dual-piston caliper
- Front Tire
- Rear Suspension
- Uni-Trak® linkage system and Showa shock with 19-position low-speed and 4-turns high-speed compression damping, 22-position rebound damping, fully adjustable spring preload
- Rear Brakes
- Single 240mm petal disc with single-piston caliper
- Rear Tire
- Dry Weight
- Curb Weight: 233.7 lb.
- Fuel Capacity
- 1.61 gal.
- 58.1 in.
- Ground Clearance
- 13 in.
- Seat Height
- 37.2 in.
- 5 in.
- 28.7 deg.
- Five-speed with wet multi-disc manual clutch
- Final Drive
- Lime Green