Cycle News Staff | May 3, 2022
Kawasaki introduced its 2023 KX250 and KX450 motocrossers. The KX450 returns as it was but with updated graphics, however, the KX250 sees some noteworthy updates.
Kawasaki says the KX250’s engine has been tuned for “stronger performance across the rev-range” and suspension settings have been updated for “greater front-end feedback” and improved “performance at the exit of the corner, contributing to strong acceleration.”
Gearing has also been revised.
The KX250 also gets new Dunlop MX33 tires and a wider 110/90 rear tire.
New and lighter footpegs are wider, as well.
Both the 2023 KX250 ($8499) and KX450 ($9599) are now available.
Giving Kawasaki more Supercross and Motocross championships than any other manufacturer, the KX name is synonymous with winning. The KX250 motorcycle is the championship-proven machine built so you can ‘Be Next’. Be the next champion. Be the next hero. Be the next legend. Be the next trailblazer for an entire generation of greatness. On the KX250, your time is now.
Thanks to an updated engine, the most powerful KX250 to date was achieved, increasing performance at all rpm. Complementing the improved power is the new racer-friendly gearing, revised suspension settings, and new tires that offer improved handling when cornering. Together, these updates contribute to quicker lap times that make the KX250 an even more potent weapon on the racetrack.
With a championship heritage that boasts 18 AMA professional titles and 194 race wins since 2004, the KX250 is the ideal platform for riders looking to reach the top step of the podium or take their riding to the next level.
In addition to the KX250, the KX250X cross country model returns for 2023 and shares many of the updates found on its motocross counterpart. The KX250X has been purposely tuned for closed-course off-road to dominate race courses in both the woods and the desert, offering riders the required components for off-road competition.
2023 KX250 HIGHLIGHTS
- NEW Increased engine performance
- NEW Racer-friendly gearing
- NEW Fine-tuned suspension
- NEW Dunlop MX33 tires with a wider 110/90-19 rear tire
- NEW Lighter and wider footpeg design
- NEW Increased engine performance
- NEW Intake valves and valve pitch
- NEW Straighter intake duct
- NEW Repositioned upstream injector
- NEW Longer exhaust header pipe
- NEW Advanced ignition timing
- NEW Racer-friendly gearing
Tuned for race-experienced riders, the 249cc liquid-cooled, four-stroke engine receives several updates for 2023 that are designed to help the KX250 achieve stronger performance across the rev-range and result in quicker lap times and better holeshot performance.
The KX250 continues to utilize the finger-follower valve actuation – a valve train designed by Kawasaki’s World Superbike engineers – to help achieve a high rev limit that allows for the use of more aggressive cam profiles and contributes to high rpm performance. For 2023, the KX250 receives a 1.5mm narrower pitch for the intake valves and increased clearance at the valve seats to deliver increased cylinder-filling efficiency and improved combustion for improved peak performance. The intake valves have been reduced by 1mm for increased cylinder head and valve seat reliability as well as to accommodate the tighter valve pitch. To match the valve size and pitch changes, the crown on the 14.1:1 bridged-box piston has been redesigned. A dry film lubricant coating on the piston skirts reduces friction at low rpm and helps with the piston bedding-in process.
The airbox construction features a short, tapered intake funnel, contributing to increased high rpm performance. The KX250 was the first production motocross bike with dual injectors. An injector downstream of the throttle valve is tasked with delivering a smooth, instant response, and a second, upstream injector located close to the airbox is a significant contributor to engine output at high rpm. For 2023, the downdraft-style intake duct is now straighter and the upstream injector has been repositioned from above to below the duct. These changes further contribute to increased cylinder-filling efficiency, adding to the KX250’s peak performance.
New advanced ignition timing was developed to complement the engine changes made to the KX250. A 100mm longer exhaust header pipe offers increased low-mid torque. In addition to increased performance, Kawasaki engineers focused on a racer-friendly power delivery, which was achieved by increasing the moment of inertia in the magneto rotor. The coned disc-spring hydraulic clutch pushrod has been revised from steel to a steel cap and aluminum shaft, resulting in lighter clutch operation. The hydraulic clutch is designed to provide a more consistent feeling through minimal change in clutch play as the clutch heats up during heavy use.
Based on feedback from Kawasaki’s efforts with the Monster Energy/Pro Circuit/Kawasaki racing team in both supercross and motocross, engineers have lengthened the transmission’s first gear to make it easier to use in a greater number of situations. Second gear was also fine-tuned to offer a smooth transition from first to third gear. For increased strength, the connecting rod big-end bearing crush height was increased and the main holding circuit relay was revised for improved reliability.
The KX250 features an electric start, which can be activated by the push of a button located on the handlebar near the right grip, making starting easy and convenient. A lightweight, compact Li-ion battery helps keep weight down, as does an automatic centrifugal decompression system fitted to the exhaust cam, which lifts one exhaust valve to facilitate starting.
Contributing to the race-winning engine characteristics, the digital fuel injection system of the KX250 features a coupler package that has set the industry standard ECU tuning. Each KX250 motorcycle comes standard with three different couplers, easily allowing riders to select pre-programmed fuel injection and ignition mapping to suit their riding style or track conditions. The four-pin couplers for the DFI® engine select maps that are designed for standard, hard or soft terrain settings. Changing the engine map is as simple as connecting the coupler cap of choice. For riders looking to fine-tune their ECU settings, the KX™ FI Calibration Kit (Handheld) is offered as a Kawasaki Genuine Accessory and provides access to the fully programmable ECU. Used by the factory race teams, the handheld device eliminates the need for a trackside laptop and gives riders the ability to create custom maps for precise adjustment of fuel and ignition settings. The user-friendly device can store up to seven preset maps and is PC-compatible.
The launch control system of the KX250 motorcycle is a major advantage and favorite for riders who are focused on getting to the first turn ahead of their competition. The push-button activation retards ignition timing in first and second gear, helping maximize traction on surfaces like concrete starting pads and put the bike’s potent power to the ground. Once the rider shifts into third gear, normal ignition mapping immediately resumes and full power is restored.
The KX250’s slim aluminum perimeter frame is based on that of the KX™450 motorcycle and with lightweight, nimble handling, and slim ergonomics in mind. Its design is a lightweight construction composed of forged, extruded, and cast parts. The frame offers optimized rigidity balance, and while many of the parts are common with the KX450’s frame, the cast parts like the shock tower mount and engine hangers were designed specifically for the needs of the KX250. Adding to the frame’s rigidity balance is the use of the engine as a stressed member.
Like the KX450, the KX250 also utilizes a swingarm to deliver the rigidity necessary to match the frame and help increase traction at the rear wheel. The center of gravity and key dimensions such as swingarm pivot, output sprocket and rear axle locations have all been carefully selected so that the rear tire drives the bike forward.
- NEW Fine-tuned suspension
- NEW Lighter bolts
For 2023, the front and rear suspension settings have been revised, contributing to improved cornering. These changes help provide the rider with greater front-end feedback and contribute to a more planted feel upon corner entry. Additionally, ground-holding performance has been improved and makes it easier for the rider to hold their selected line through a corner. The rear suspension updates are designed to improve performance at the exit of the corner, contributing to strong acceleration.
The KX250 is equipped with large diameter 48mm KYB inverted coil-spring front forks that offer optimum action at the initial part of the fork stroke. The forks feature large-diameter inner tubes, enabling the use of 25mm damping pistons and delivering smooth action and firm damping. Fork internals have been fine-tuned to deliver firmer compression damping to achieve increased performance without sacrificing ride comfort. A revised oil height on the front forks contributes to optimized characteristics of the front fork springs. A Kashima Coat on the forks’ outer tubes creates a hard, low-friction surface to help prevent wear abrasion on the inside of the tubes, ensuring the sliding surfaces remain smooth over time while protecting the outside against corrosion. The lubricating material in the coat contributes to smoother suspension action and a better overall ride feel.
In the rear, a KYB shock unit complements the front fork. The rear shock features dual compression adjustability, which allows high-speed and low-speed damping to be tuned separately. New shock valving settings enable firmer compression damping that improves performance while maintaining the comfort the KX250 is known for. A Kashima Coat on the tank cylinder helps prevent wear abrasion and reduces friction for smoother suspension action. A new Uni-Trak® rear suspension system mounts the linkage arm below the swingarm, allowing a longer rear suspension stroke. The linkage ratios are the same as those found on the KX450 motorcycle, contributing to both increased absorption and damping performance. In order to make the KX250 as light as possible, the fork cover bolts were changed from steel to aluminium and the rear linkage collar was changed from steel to aluminium and now uses hollow instead of solid bolts.
BRAKES AND WHEELS
- NEW Dunlop MX33 tires
- NEW Wider, 110/90-19 rear tire sizing
Contributing to the numerous factory-style racing components on the KX250 motorcycle are petal disc brakes. Up front is an oversized 270mm Braking® brand rotor, which delivers strong braking force and superb control. A KX450-style front master cylinder adds to the high level of control and overall feedback found in the front brake.
On the rear, a 240mm Braking brand disc contributes to controllability and offers optimized stopping performance. The petal-style discs contribute to both sporty looks and help deflect debris. A rear caliper guard helps protect the caliper from damage.
For 2023, the KX250 has been fitted with new Dunlop MX33 tires, offering increased traction to match the more powerful engine. The front features 80/100-21 sizing, while the rear can now be found in a wider 110/90-19 sizing for increased traction and a more planted rear-end feel.
- NEW Lighter and wider footpeg design
Kawasaki continues its unmatched commitment towards providing riders with class-leading comfort thanks to its ERGO-FIT® adjustable handlebar mounting system and footpegs to fit a variety of riders and riding styles. New for 2023 is a revised wide-style footpeg design that is now 5mm wider (front-to-rear) and positioned 3mm rearward, offering excellent grip, superb feel, and making it easier to weight the pegs. This new design is also lighter thanks to aluminum footpeg brackets replacing the previous steel brackets. The weight savings of the footpegs, along with the suspension changes, contribute to a weight savings of almost one pound, helping offset the new larger rear tire.
A factory-style 1-1/8” thick aluminum Renthal® Fatbar® handlebar comes standard and features four-way adjustable mounts. The multi-position handlebars offer two mounting holes with 35mm of adjustability, and the 180-degree offset clamps boast four individual settings to suit different size riders. The footpegs feature dual-position mounting points, with a lower position that reduces the standard setting by an additional 5mm. The lower position effectively lowers the center of gravity when standing, and reduces knee angle when taller riders are seated.
BODYWORK AND STYLING
Complementing the increased engine power and improved handling of the 2023 KX250 is sleek bodywork with factory-style graphics that helps ensure it’s the sharpest looking bike in the paddock and further reflect its highly-tuned performance. The bodywork on the KX250 has been designed to facilitate rider movement with long, smooth surfaces that make it easy to slide back and forth. The seams between the shrouds, seat, and side covers are as flush as possible to help the rider move around on the bike. The top of the fuel tank allows a flat progression from the seat to the tank, which gives the rider greater freedom of movement when changing riding position and facilitates sitting farther forward. The single-piece radiator shrouds are slim where they come in contact with the rider’s legs and positioned close to the frame. In-mold graphics result in an ultra-smooth surface and contribute to the KX250’s factory-racer looks.
Engine covers have been designed to be as smooth as possible in order to not impede rider movement. Helping the KX250 retain its factory-style look is a gold finish on the oil cap and the two plugs on the generator cover, while the rims are coated in black alumite. CN