Kawasaki KX 250F [2012-2017]: A Motocross Warrior Built for Precision
Introduction
The Kawasaki KX 250F solidified its reputation as a fierce competitor in the 250cc motocross segment during its 2012-2017 production run. Designed for riders who demand precision, agility, and relentless power delivery, this bike became a favorite for both amateur racers and seasoned pros. While its lime green livery screams Kawasaki’s racing heritage, it’s the engineering beneath the plastics that truly defines this machine. After spending a day thrashing a well-maintained 2016 model on a technical motocross track, it’s clear why this generation remains a benchmark in its class.
Riding Experience: Where Aggression Meets Control
Engine Performance: Linear Power, Maximum Excitement
The heart of the KX 250F is its 249cc liquid-cooled, four-stroke single-cylinder engine. With a 13.8:1 compression ratio and dual fuel injectors (Keihin’s 43mm throttle body), this mill delivers power that’s both explosive and remarkably linear. The DOHC valvetrain ensures crisp throttle response, while the 5-speed transmission slots through gears with a satisfying mechanical snick.
On the track, the engine shines in its ability to pull cleanly from mid-range revs. There’s no sudden hit of power—just a relentless surge that rewards riders who keep the RPMs dancing between 8,000 and 13,000. The kickstarter requires a firm boot, but once fired up, the engine idles smoothly at 2,050 ± 50 RPM, a testament to Kawasaki’s fine-tuning of the digital DC-CDI ignition.
Chassis and Suspension: Confidence in Chaos
Kawasaki’s aluminum perimeter frame strikes a perfect balance between rigidity and flex. At 1,476 mm (58.1 inches) of wheelbase and a 28.7° rake angle, the bike feels planted in high-speed straights yet remains flickable through tight corners.
The suspension setup is where the KX 250F truly separates itself from the pack: - Front: The 48mm Showa Separate Function Fork (SFF) Type 2 offers 315 mm (12.4 inches) of travel, with 40-way spring preload adjustability and 22-position compression damping. - Rear: Showa’s Uni-Trak shock provides 310 mm (12.2 inches) of wheel travel, featuring 19-way low-speed compression, 4-turn high-speed compression, and 22-way rebound damping.
During my test ride, the front fork absorbed braking bumps and small chop effortlessly, while the rear remained composed over larger jumps. Even at 940 mm (37 inches) of seat height, the bike’s 104.5–106 kg (230–234 lb) wet weight makes it feel surprisingly manageable in the air.
Ergonomics and Braking: Built for Attack
The KX 250F’s cockpit is minimalist and aggressive. The Renthal Fatbar (absent on earlier models but a common upgrade) provides a commanding grip, while the narrow aluminum fuel tank (6.09L / 1.61 US gal) allows for easy weight shifting. Standing up through rutted corners feels natural, thanks to the 330 mm (13 inches) of ground clearance.
Braking is handled by petal discs:
- Front: 240 mm rotor with a twin-piston caliper
- Rear: 240 mm rotor with a single-piston caliper
The initial bite is progressive rather than abrupt—ideal for maintaining traction on loose surfaces. After three hard laps, there was no noticeable fade, though upgrading to sintered pads (available at MOTOPARTS.store) could enhance performance for aggressive riders.
Competition: How the KX 250F Stacks Up
Yamaha YZ250F
Yamaha’s offering rivals the KX with its rearward-slanted cylinder design for mass centralization. While the YZ feels slightly more agile at low speeds, the Kawasaki’s mid-range torque and suspension adjustability give it an edge on technical tracks.
Honda CRF250R
Honda’s Uni-Cam engine prioritizes reliability over outright power. The CRF250R is smoother for beginners but lacks the KX’s explosive character. Kawasaki’s Showa suspension also outperforms Honda’s Showa/SKYHOOK setup in stock form.
KTM 250 SX-F
The Austrian contender weighs less (102 kg / 225 lb) and features electric start—a luxury the KX lacks. However, the KTM’s WP suspension demands more frequent tuning, whereas the Kawasaki’s Showa components are forgiving across varying skill levels.
Verdict: The KX 250F strikes a middle ground between raw power (KTM) and beginner-friendliness (Honda). Its standout feature remains the highly tunable suspension, making it a versatile choice for riders tackling diverse track conditions.
Maintenance: Keeping the Green Machine in Fighting Shape
Valve Adjustments: Precision Matters
The DOHC engine demands strict adherence to valve clearances:
- Intake: 0.10–0.15 mm (0.004–0.006 in)
- Exhaust: 0.17–0.22 mm (0.007–0.009 in)
Check every 15–20 hours of ride time. Use a feeler gauge and keep shim kits (available at MOTOPARTS.store) on hand for adjustments.
Oil and Fluids: Lifeblood of Performance
- Engine Oil: 800 ml (0.85 qt) of SAE 5W-40/10W-40 (API SG or higher). Change every 10 hours.
- Coolant: 1.2L (1.27 qt) of ethylene glycol-based mix. Inspect for leaks after heavy sessions.
- Brake Fluid: DOT 4. Replace annually or when sponginess occurs.
Chain and Sprockets: Power Transfer Essentials
The 520 chain with 13/50 sprockets (114 links) wears quickly under race conditions. Clean with a dedicated chain brush and lubricate after every ride. Consider upgrading to a DID ERV3 chain for extended durability.
Tire Pressure: Grip vs. Puncture Resistance
- Front: 1.0 bar (14.5 psi)
- Rear: 1.0 bar (14.5 psi)
Lower to 0.8 bar (11.6 psi) for muddy conditions, but avoid pinch flats by adding mousse bibs (available in our store).
Final Thoughts: A Legacy of Reliability and Thrills
The Kawasaki KX 250F [2012–2017] remains a compelling choice for riders seeking a motocross bike that balances aggression with adaptability. While newer models boast flashier tech, this generation’s bulletproof engine and sublime suspension tuning ensure it’s still a force to be reckoned with. Whether you’re rebuilding a used gem or optimizing a race-ready machine, MOTOPARTS.store offers everything from OEM-spec spark plugs (NGK CPR8EB-9) to performance exhausts—ensuring your KX stays ahead of the pack.
The KX 250F mid-air: A blend of balance and brute force.
Specifications sheet
| Engine | |
|---|---|
| Stroke: | Four-stroke |
| Max power: | 32 kW | 43.0 hp |
| Fuel system: | Keihin DFI 43mm throttle body with dual injectors |
| Displacement: | 249 ccm |
| Bore x stroke: | 77.0 x 53.6 mm (3.0 x 2.1 in) |
| Configuration: | Single |
| Cooling system: | Liquid |
| Compression ratio: | 13.8:1 |
| Number of cylinders: | 1 |
| Valves per cylinder: | 4 |
| Dimensions | |
|---|---|
| Wheelbase: | 1476 mm (58.1 in) |
| Wet weight: | 106 |
| Seat height: | 945 mm (37.2 in) |
| Overall width: | 820 mm (32.3 in) |
| Overall height: | 1270 mm (50.0 in) |
| Overall length: | 2169 mm (85.4 in) |
| Ground clearance: | 330 mm (13.0 in) |
| Fuel tank capacity: | 7.2 L (1.9 US gal) |
| Drivetrain | |
|---|---|
| Chain type: | 520 |
| Final drive: | chain |
| Chain length: | 114 |
| Transmission: | 5-speed |
| Rear sprocket: | 50 |
| Front sprocket: | 13 |
| Maintenance | |
|---|---|
| Rear tire: | 100/90-19 |
| Engine oil: | SAE 5W-40/10W-40 |
| Front tire: | 80/100-21 |
| Brake fluid: | DOT 4 |
| Spark plugs: | NGK CPR8EB-9, NGK CPR9EB-9 |
| Spark plug gap: | 0.8 |
| Coolant capacity: | 1.2 |
| Engine oil capacity: | 0.8 |
| Engine oil change interval: | Every 15 hours or 500 km, whichever comes first |
| Valve clearance (intake, cold): | 0.10–0.15 mm |
| Valve clearance check interval: | Check every 15 hours of operation |
| Valve clearance (exhaust, cold): | 0.17–0.22 mm |
| Recommended tire pressure (rear): | 1.0 bar (14.5 psi) |
| Recommended tire pressure (front): | 1.0 bar (14.5 psi) |
| Chassis and Suspension | |
|---|---|
| Frame: | Aluminum perimeter |
| Trail: | 127 mm (5.0 in) |
| Rear brakes: | Single 240 mm petal disc, 1-piston caliper |
| Front brakes: | Single 240 mm petal disc, 2-piston caliper |
| Rear suspension: | Uni-Trak linkage system with Showa shock, 9-position low-speed compression, stepless high-speed compression, 22-position rebound damping |
| Front suspension: | 48mm inverted Showa SFF telescopic fork, 40-way spring preload, 22-position compression, 20-position rebound damping |
| Rake (fork angle): | 28.7° |
| Rear wheel travel: | 310 mm (12.2 in) |
| Front wheel travel: | 315 mm (12.4 in) |
