| Engine type | Liquid-cooled, 4-stroke Single |
| Displacement | 249cc |
| Bore x stroke | 78 x 52.2 mm |
| Compression ratio | 14.0:1 |
| Valve/Induction system | DOHC, 4 valves |
| Fuel system | Fuel injection: 44 mm |
| Ignition | Digital DC-CDI |
| Starting | Electric |
| Lubrication | Forced lubrication, semi‑dry sump |
| Transmission | 5-speed, return |
| Final Drive | Chain |
| Primary reduction ratio | 3.350 (67/20) |
| Gear ratios: 1st | 2.077 (27/13) |
| Gear ratios: 2nd | 1.688 (27/16) |
| Gear ratios: 3rd | 1.438 (23/16) |
| Gear ratios: 4th | 1.235 (21/17) |
| Gear ratios: 5th | 1.045 (23/22) |
| Final reduction ratio | 3.846 (50/13) |
| Clutch | Wet multi-disc, manual |
| Frame type | Perimeter, aluminium |
| Rake/Trail | Rake: 27 / Trail: 118mm |
| Wheel travel - front | 305 mm |
| Wheel travel - rear | 307 mm |
| Tyre - front | 80/100-21 51M |
| Tyre - rear | 110/90-19 63M |
| Steering angle - left / right | 42 / 42 |
| Suspension - front | 49 mm inverted telescopic fork with adjustable compression and rebound damping |
| Suspension - rear | New Uni Trak with adjustable dual-range (high/low-speed) compression damping, adjustable rebound damping and adjustable preload |
| Brakes - front | Single semi-floating 270 mm petal disc. Caliper: Dual-piston |
| Brakes - rear | Single 240 mm petal disc Caliper: Single-piston |
| Dimensions (L x W x H) | 2,190 x 820 x 1,265 mm |
| Wheelbase | 1,485 mm |
| Ground Clearance | 340 mm |
| Seat height | 955mm |
| Fuel capacity | 6.2 litres |
| Curb Mass | 109.5 kg |
Compared to a conventional clutch, the hydraulic clutch offers more direct feel and lighter lever action. Less play as the clutch heats up during heavy use results in more consistent feeling.
A symmetrically aligned intake and exhaust deliver a strong overrun and smooth low-rpm torque characteristics. Redesigned intake offers a much straighter route for air-fuel mix to enter the cylinder, while a centrally positioned exhaust port lines up with the intake for high airflow efficiency—both contributing to increased performance. The optimised downdraft intake also adds to low-end performance.
Medium-compound ODI Lock-On Grips offer excellent grip feel, while their screw-type fastening system greatly facilitates the task of swapping grips.
Already highly acclaimed for their slim ergonomics, the KX250 receives redesigned bodywork that offers an even smoother rider interface. Newly designed shrouds, side covers, and rear fender are firmer and eliminate hooking points, further facilitating rider movement.
A single-shaft primary engine balancer contributes to smoother power delivery and reduced vibration, which improves control, especially when exiting slower-speed corners.
Redesigned frame based on that of the 2024 KX450 accommodates the updates to the engine’s intake and exhaust systems, while delivering a high level of both light, nimble handling and a composed character. Optimised rigidity balance contributes to increased front-end feel that translates to improved cornering performance in a wider range of conditions.
Being able to restart an engine quickly after a spill can mean the difference between keeping your lead or having to fight your way back through the pack. Electric start makes restarting the engine as easy as pushing a button.
Factory-style launch control system increases the chance of getting a good start by helping riders maximise traction when starting on a low-traction surface.
Using the Traction (T) button on the left handlebar, riders can quickly and easily select from two levels (Weak, Strong) of traction control to suit conditions and preference. Riders may also elect to turn the system off.
Using the smartphone application “RIDEOLOGY THE APP KX,” riders are able to access and adjust their bike’s engine maps. Functionality (adjusting fuel and ignition timing) is similar to that offered by the accessory KX FI Calibration Kit used with previous models. Maintenance and setup logs are also available. *RIDEOLOGY THE APP KX is not intended for use during vehicle operation. Only use RIDEOLOGY THE APP KX when the vehicle is not being operated and it is safe to do so.
Side cover can be removed without tools, providing convenient access to the air filter element.
Complementing the significantly increased low-end torque and the smoother power delivery, throttle response is more linear, delivering lag-free power in proportion to how much the throttle grip is twisted. This greatly facilitates control, enabling smooth acceleration on challenging or low-traction surfaces, helping riders push the limits more confidently, and reducing rider fatigue so that they can more easily maintain their pace for the duration of the race.
A choice of four handlebar positions and two footpeg positions allows riders to tailor their riding position to suit body size and preference.
Using the Mode (M) button on the left handlebar, riders can quickly and easily switch between two engine maps (Normal, Aggressive) provided in the ECU.
High-performance Showa ø48 mm inverted coil-spring fork and New Uni Trak rear suspension offer race-ready suspension performance and adjustability to let riders tune their settings to suit conditions.
