Kawasaki update KX250 for 2023
Kawasaki have released the 2023 version of their KX250, with the quarter-litre motocrosser receiving a number of updates for the coming year, across engine, transmission, suspension and tyres, as well as improvements in reliability and rider ergonomics.
Following updates in 2020 and 2021, this latest update aims to keep the KX250 at the head of the pack in motocross and supercross competition. While the changes are subtle, they’ll be appreciated by racers.
Engine Changes
In terms of capacity and configuration, the KX250 engine remains unchanged at 249cc, with the liquid-cooled four-stroke single featuring the same 78 x 52.2mm bore and stroke, 14.1:1 compression, CDI ignition and electric starting.
The engine changes start with the intake valves, which now have a narrower pitch of 35.5mm (previously 37mm). Coupled with increased valve seat clearance, this change offers improved combustion and increased performance.
The valves themselves feature finger-follower actuation (as per the KX450) and are now 1mm smaller (31mm v 32mm), which allows the narrower pitch and also improves reliability of the cylinder head and valve seats. These valve changes have also necessitated changes to the piston crown.
A graph presented by Kawasaki shows improvements in both the low and high rev range achieved with these changes, while adjusting the inertial mass of the magneto rotor also contributes to providing “racer-friendly” power delivery.
The intake path to the combustion chamber is now straighter, achieved by moving the upstream injector from above to below the intake duct, with advanced ignition timing to match the improved performance.
Finally, a longer exhaust header pipe (557mmm vs 457mm) improves torque in the low- to mid-range.
The end result of all these changes is stronger performance across the rev range, allowing quicker lap times and better holeshot performance.
Finally, along with the valve changes, engine reliability improvements have also been delivered by an increased crush height for the con-rod big end bearing.
Clutch Changes
For the MY23 KX250’s transmission, a five-speed gearbox with chain final drive and a wet, multi-disc hydraulic clutch remains, but the clutch pushrod has been modified, now of combined steel and aluminium construction for lighter clutch lever operation.
Coned disc springs contribute to easier clutch operation, while also offering a wider clutch lever engagement range. There's also less play in the clutch as it heats up, ensuring a more consistent lever feel.
On the gearing, first gear is now taller, which is the result of feedback from Kawasaki’s factory teams in the US - teams that have delivered the most 250cc class titles of any manufacturer in AMA MX and SX competition.
In harmony with the taller first gear, there has been a revision to the second gear to allow a smoother transition from first to third.
Suspension Changes
While racer feedback in the US led to the gearing changes, riders in the All-Japan Motocross series have seen the KX250 suspension stiffened for 2023.
At the front end, fine-tuning of the 48mm KYB inverted fork internals deliver firmer compression damping that, according to Kawasaki, improves cornering and increases off-road performance without sacrificing rider comfort.
While the spring rate is unchanged, revised oil levels optimise overall spring characteristics, providing a better, more planted feel.
At the back end, firmer compression damping on the KYB Uni-Trak monoshock allows for faster acceleration out of corners. Dual low- and high-speed compression adjustment remains.
To reduce weight, steel has been replaced with aluminium in selected areas of the suspension, including the fork cover bolts and rear linkage collar. Hollow bolts are also used on the latter.
Tyre and Peg Changes
For 2023, the KX250 adopts a new tread pattern for its standard Dunlop MX33 tyres, which allow the extra engine power to be best utilised.
More significantly, the rear tyre has been upsized from 100/90-19 to 110/90-19, with this increase in width improving traction and providing a more planted feel in concert with the suspension changes.
To offset the extra weight of the larger, wider rear tyre, the footpeg brackets are now in aluminium instead of steel, with the pegs themselves sitting 3mm rearward compared to the MY22 KX250.
The pegs are also 5mm wider front-to-back, improving boot contact area and reducing rider strain.
Still Green
The adjustments and additions to the 2023 KX250 have increased weight fractionally to 108kg wet (previously 107.5kg), with seat height up 10mm to 960mm.
The aforementioned changes aside, the KX250 is unchanged for 2023, with a lightweight aluminium perimeter frame and swingarm based on the KX450, using the engine as a stressed member.
Other carryover features include electric starting, a lightweight lithium-ion battery, three-mode plug-and-play engine mapping, launch control, a four-position adjustable factory-style Renthal handlebar, adjustable footpeg positions and slim bodywork.
That bodywork is designed to facilitate rider movement fore and aft, with a narrow cross section, long, smooth surfaces and flush seams between the radiator shrouds, seat and sidecovers. The seat features a textured top and smooth sides to balance grip when seated with easier movement when up on the pegs.
Petal brake discs, 270mm front and 240mm rear, are gripped by a two-piston caliper at the front and single-piston caliper at the rear.
On the engine mapping, each of the three DFI couplers can be adjusted using the Kawasaki KX FI Calibration Kit, which is available as an extra-cost accessory.
Kawasaki’s signature Lime Green remains and is the only colour choice for the 2023 KX250.
Coloured highlights feature on the oil cap and gen cover plugs, with a green alumite finish on the suspension adjusters.
Black rims are standard, while in-mould graphics on the radiator shrouds are designed to withstand long hours of use in rough MX conditions.
The 2023 KX250 is available now, priced from $12,443. See your Kawasaki dealer for more details.
