In the over 40 years since the brand was launched, the KX design philosophy – to put mid-level to expert riders on the top step of the podium – has remained unchanged. The philosophy has served Kawasaki well: in the extremely competitive 4-stroke 250cc class Kawasaki race machines have helped capture the most AMA Supercross and Motocross titles.
After benefitting from major updates in 2020 and 2021, further revisions the resulted in significantly increased performance. Engine updates deliver increased performance at all rpm, while new tyres and revised suspension settings offer improved handling when cornering. The resultant quicker lap times make the KX250 an even more potent track weapon.
Stronger performance across the rev-range translates to quicker lap times and better holeshot performance.
Narrower pitch for the intake valves (37 mm >> 35.5 mm) coupled with increased clearance at the valve seats delivers increased cylinder-filling efficiency and improved combustion for increased peak performance. The valves themselves are smaller (ø32 mm >> ø31 mm), which contributes to cylinder-head/valve-seat reliability while enabling the tighter valve pitch. Piston crown revised to match the valve size and pitch changes.
Downdraft-style intake duct is straighter, and the upstream injector is repositioned from above to below the duct. These changes further contribute to increased cylinder-filling efficiency, which adds to peak performance.
Magneto rotor with an increased moment of inertia (9.5 kg·cm2 >> 10.0 kg·cm2) contributes to racer-friendly power delivery.
Revised material for the clutch pushrod (steel >> steel cap + aluminium shaft) results in lighter clutch operation.
Based on feedback from Kawasaki’s factory racing efforts in AMA Supercross, a longer 1st gear makes it easier to use in a greater number of situations. 2nd gear ratio was also fine-tuned to offer a smooth transition from 1st to 3rd gear.
Connecting rod big-end bearing crush height was increased, contributing to reliability and durability. Revised main holding circuit relay contributes to general reliability.
Front and rear suspension setting updates contribute to improved cornering. On corner entry, greater front-end feedback contributes to a more planted feel. Increased ground-holding performance makes it easier to hold a chosen line through the corner. After exiting the corner, revised rear suspension settings contribute to stronger acceleration.
Dunlop MX33 tyres offer increased traction to match the engine’s increased power. (Brazilian-market models use Pirelli Scorpion MX32 tyres, as before.
Wider 110/90-19 rear tyre (previously 100/90-19) contributes to increased rear wheel traction as well as a greater planted feeling. (Brazilian-market models use a 100/90-19 rear tyre, as before.
Revised footpeg design is 5 mm wider (front-to-rear) and positioned 3 mm rearward, offering excellent grip, superb feel, and making it easier to weight the pegs.
The new design (with aluminium instead of steel brackets) is also lighter. Along with the weight-saving changes to the suspension, they offer 430 g in savings, which help offset the larger (and heavier) rear tyre.
Stronger performance across the rev-range translates to quicker lap times and better holeshot performance.
Narrower pitch for the intake valves (37 mm >> 35.5 mm) coupled with increased clearance at the valve seats delivers increased cylinder-filling efficiency and improved combustion for increased peak performance. The valves themselves are smaller (ø32 mm >> ø31 mm), which contributes to cylinder-head/valve-seat reliability while enabling the tighter valve pitch. Piston crown revised to match the valve size and pitch changes.
Downdraft-style intake duct is straighter, and the upstream injector is repositioned from above to below the duct. These changes further contribute to increased cylinder-filling efficiency, which adds to peak performance.
Magneto rotor with an increased moment of inertia (9.5 kg·cm2 >> 10.0 kg·cm2) contributes to racer-friendly power delivery.
Revised material for the clutch pushrod (steel >> steel cap + aluminium shaft) results in lighter clutch operation.
Based on feedback from Kawasaki’s factory racing efforts in AMA Supercross, a longer 1st gear makes it easier to use in a greater number of situations. 2nd gear ratio was also fine-tuned to offer a smooth transition from 1st to 3rd gear.
Connecting rod big-end bearing crush height was increased, contributing to reliability and durability. Revised main holding circuit relay contributes to general reliability.
Front and rear suspension setting updates contribute to improved cornering. On corner entry, greater front-end feedback contributes to a more planted feel. Increased ground-holding performance makes it easier to hold a chosen line through the corner. After exiting the corner, revised rear suspension settings contribute to stronger acceleration.
Dunlop MX33 tyres offer increased traction to match the engine’s increased power. (Brazilian-market models use Pirelli Scorpion MX32 tyres, as before.
Wider 110/90-19 rear tyre (previously 100/90-19) contributes to increased rear wheel traction as well as a greater planted feeling. (Brazilian-market models use a 100/90-19 rear tyre, as before.
Revised footpeg design is 5 mm wider (front-to-rear) and positioned 3 mm rearward, offering excellent grip, superb feel, and making it easier to weight the pegs.
The new design (with aluminium instead of steel brackets) is also lighter. Along with the weight-saving changes to the suspension, they offer 430 g in savings, which help offset the larger (and heavier) rear tyre.
| DIMENSIONS | |
|---|---|
| Overall length | 2,190 mm |
| Overall width | 820 mm |
| Overall height | 1,270 mm |
| Wheelbase | 1,485 mm |
| Road clearance | 345 mm |
| Seat height | 960 mm |
| Curb mass | 108 kg |
| Dry mass | 102.9 kg |
| Fuel tank capacity | 6.2 litres |
| PERFORMANCE | |
|---|---|
| Max. power | - |
| Max. Power with Ram Air | - |
| Max. torque | - |
| ENGINE | |
|---|---|
| Type / Valve system | 4-stroke Single |
| Coolant System | Liquid-cooled |
| Bore x Stroke | 78.0 x 52.2 mm |
| Displacement | 249 cm3 |
| Compression ratio | 14.1:1 |
| Fuel supply | Fuel injection (ø44 mm x 1) |
| Lubrication system | Forced Lub. Semi-dry sump |
| Starting system | EL. Starter |
| Ignition system | Digital DC-CDI |
| DRIVETRAIN | |
|---|---|
| Driving system | Chain |
| Transmission | 5-speed, return |
| Primary reduction ratio | 3.350 (67/20) |
| 1st Gear ratios | 2.154 (28/13) |
| 2st Gear ratios | 1.733 (26/15) |
| 3st Gear ratios | 1.438 (23/16) |
| 4st Gear ratios | 1.235 (21/17) |
| 5st Gear ratios | 1.045 (23/22) |
| 6st Gear ratios | - |
| Final reduction ratio | 3.846 (50/13) |
| Clutch type (Primary) | Wet multi-disc, manua |
| FRAME | |
|---|---|
| Type | Tubular, semi-double cradle |
| Front Suspension | ø48 mm inverted telescopic fork with adjustable compression and rebound damping |
| Rear Suspension | New Uni Trak with adjustable dual-range (high/low-speed) compression damping, adjustable rebound damping and adjustable preload |
| Front Wheel travel | 314 mm |
| Rear Wheel travel | 316 mm |
| Caster (Rake angle) | 28.0° |
| Trail | 118 mm |
| Steering angle (left/right) | 42° / 42° |
| Front Tyre | 80/100-21 51M |
| Rear Tyre | 110/90-19 62M |
| Front Type Brake | Single disc |
| Caliper (Front) | Dual-piston |
| Rear Type Brake | Single disc |
| Caliper (Rear) | Single-piston |
