Kawasaki’s quarter-liter off-road platforms get a major reworking this year. The 2025 Kawasaki KX250 motocross bike and KX250X off-road racer get updates to the top-end of the DOHC motor with enhanced electronics, a new frame, new Showa suspension, narrower ergonomics, and more—pretty much a rerun of what we saw on last year’s KX450, and we’re not about to complain about that. The KX250 and KX250X bikes are nearly identical, so unless we mention otherwise, the changes apply to both dirt bikes.
- Let’s start with the new intake tract, and work down the combustion process. After running dirt air through a new airbox and filter, Kawasaki engineers steepened the intake to 34 degrees to give the charge a superior shot at the new intake ports’ layout of the new cylinder head. The dual injector Keihin 44mm throttle body gets a diet, and the primary injector is 11mm closer to the valves. Also, the butterfly valve orientation is swapped so the top opens first. Kawasaki says this change improves throttle response thanks to better fuel atomization. Also, the intake and exhaust ports are now lined up symmetrically, which Kawasaki says boosts power from idle to the midrange thanks to improved efficiency of the intake and exhaust valves. More low-end boost comes from raising the intake cam 10mm to accommodate the new intake angle and one-degree steeper intake valves’ angle.
- The cylinder on the 2025 Kawasaki KX250 is tilted five degrees forward, and the compression lowered a touch thanks to a new piston. The forward tilt of the top end is part of the new downdraft intake. The piston gets a nine percent flatter crown to complement the steeper intake valve angle. Kawasaki tells us that the compression ratio reduction from 14.1:1 to 14.0:1 smooths out low-rpm power delivery. In the bottom end, there’s a new single-shaft counterbalancer. In addition to cutting vibration, it’s also intended to smooth low-rpm throttle response.
- Exhaust gasses exit via a new center port. This ties in with the new frame, which we haven’t discussed yet. The change in the flow of the exhaust gasses allowed Kawasaki to move the muffler two inches forward to enhance mass centralization and improve handling.
- Modern power modes come to the 2025 Kawasaki KX250 and KX250X. Put your KX FI Calibration Kit and any couplers you have on eBay, Craigslist, or Facebook Marketplace. The engine can now be tuned wirelessly with Rideology The App KX loaded into your smartphone. The rider uses a left-handlebar button to switch between two modes—either the factory modes, or your own home-brew tuning. There’s also two-level (plus off) traction control and launch control mode. The Rideology KX app also gives you real-time engine monitoring, plus a maintenance log.
- The entire twin-spar aluminum frame is reworked, and loses a half-pound. The downtube from the steering head is completely redesigned to accept the new center-port exhaust. The Y split is newly five inches higher and reworked. Also, the cross pipe between the twin aluminum spars has been changed as part of the steeper intake design. Also, with the new Showa suspension comes a lower shock mount, new swingarm bracket ribbing, and a square lower-cross pipe. Kawasaki has increased torsional rigidity for better front-end feel, and the rear engine brackets are now aluminum (replacing steel) to ensure the KX250 doesn’t feel too stiff.
- Kawasaki has fitted the 2025 KX250 and KX250X with Showa suspension, which the KX450s have had for the better part of a decade. The suspension travel is slightly reduced from last year, with new settings to balance the new chassis and engine performance. Also, the fork tubes get a Kashima Coat for smoother operation.
- New shrouds and side covers promise smoother transitions through the plastic. They’re also firmer to provide a more reliable interface with the rider. Air filter access requires no tools. Also, the Renthal Fatbar gets ODI lock-on grips.
- Kawasaki is being cagey about the chassis setup on the 2025 KX250X off-road racer. We’re going to have to wait to find out what the wet weight, wheelbase, rake, trail, seat height, and ground clearance will be on the dirt bike, which will also serve as a trail bike for skilled riders. Returning on the KX250X is an off-road-specific suspension settings, an 18-inch rear wheel, a sealed chain, and a kickstand. The 2025 Kawasaki KX250 gets new Dunlop Geomax MX34 tires, while the KX250X sticks with off-road-friendly Dunlop Geomax AT81 rubber.
- The 2025 Kawasaki KX250 and KX250X will debut on showroom floors this summer. That means sometime between June 20 and September 22. Both bikes are available in one color—Lime Green, naturally. The KX250 has an MSRP of $8999, and the off-road-appointed KX250X has a $100 premium.
2025 Kawasaki KX250 (and KX250X) Specs
ENGINE
- Type: Single-cylinder four-stroke
- Displacement: 249cc
- Bore x stroke: 78.0 x 52.2mm
- Valvetrain: DOHC; 4 valves
- Compression ratio: 14.0:1
- Starting: Electric
- Fueling: EFI w/ 44mm Keihin throttle body w/ dual injectors
- Transmission: 5-speed
- Clutch: Hydraulically actuated w/ coned-disc spring
- Final drive: Chain (KX250X: sealed chain)
CHASSIS
- Frame: Aluminum perimeter
- Handlebar: 4-position-adjustable Renthal Fatbar w/ ODI Grips
- Front suspension; travel: Compression- and rebound-damping adjustable Showa 48mm inverted fork; 12.0 inches
- Rear suspension; travel: Linkage-assisted fully adjustable Showa piggyback reservoir shock; 12.1 inches
- Tires: Dunlop Geomax MX34 (KX250X: Dunlop Geomax AT81)
- Front tire: 80/100 x 21
- Rear tire: (KX250X: 110/100 x 18)
- Front brake: Semi-floating 270mm Braking petal disc w/ 2-piston Nissin caliper
- Rear brake: Single 240mm petal disc w/ single-piston Nissin caliper
DIMENSIONS and CAPACITIES
- Wheelbase: 58.5 inches (KX250X: TBA)
- Rake: 27.1 degrees (KX250X: TBA)
- Trail: 4.7 inches (KX250X: TBA)
- Seat height: 37.6 inches (KX250X: TBA)
- Ground clearance: 13.4 inches (KX250X: TBA)
- Fuel tank capacity: 1.64 gallons
- Wet weight: 241 pounds (KX250X: TBA)
- Color: Lime Green
- 2025 Kawasaki KX250 Price: $8999 MSRP
- 2025 Kawasaki KX250X Price: $9099
2025 Kawasaki KX250 Photo Gallery
2025 Kawasaki KX250X Photo Gallery
2025 Kawasaki KX250 and KX250X Infographics
