Available From November 2023
| Engine type | Liquid-cooled, 4-stroke Single |
| Displacement | 449cc |
| Bore x stroke | 96 x 62.1 mm |
| Compression ratio | 12.5:1 |
| Valve/Induction system | DOHC, 4 valves |
| Fuel system | Fuel injection: 44 mm x 1 |
| Ignition | Digital DC-CDI |
| Starting | Electric |
| Lubrication | Forced lubrication, semi-dry sump |
| Transmission | 5-speed |
| Final Drive | Chain |
| Primary reduction ratio | 2.727 (60/22) |
| Gear ratios: 1st | 1.750 (28/16) |
| Gear ratios: 2nd | 1.412 (24/17) |
| Gear ratios: 3rd | 1.188 (19/16) |
| Gear ratios: 4th | 1.000 (19/19) |
| Gear ratios: 5th | 0.875 (21/24) |
| Final reduction ratio | 3.846 (50/13) |
| Clutch | Wet multi-disc, manual |
| Frame type | Perimeter, aluminium |
| Rake/Trail | Trial: 115 mm |
| Wheel travel - front | 305 mm |
| Wheel travel - rear | 307 mm |
| Tyre - front | 80/100-21 51M |
| Tyre - rear | 120/80-19 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/lowspeed) compression damping, adjustable rebound damping and adjustable preload. |
| Brakes - front | Single semi-floating 270 mm petal disc. Caliper: Brembo Dual-piston |
| Brakes - rear | Single 240 mm petal disc. Caliper: Single-piston |
| Dimensions (L x W x H) | 2,180 x 820 x 1,270 mm |
| Wheelbase | 1,480 mm |
| Ground Clearance | 345 mm |
| Seat height | 960 mm |
| Fuel capacity | 6.2 litres |
| Curb Mass | 112.6 kg |
Factory-style ø49 mm inverted coil-spring front fork and New Uni Trak rear suspension offer race-ready suspension performance and adjustability to let riders tune their settings to suit conditions.
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.
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 KX450 and KX450X receive 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.
Side cover can be removed without tools, facilitating access to the air filter element.
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.
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.
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.
Redesigned frame 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.
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.
Revised brake components include drilled Braking/Sunstar discs (ø270/240 mm) paired with a Brembo caliper and master cylinder at the front and a Nissin caliper and master cylinder at the rear. The high-performance system offers increased controllability on the brakes, contributing to enhanced corner entry.
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, Mild response) provided in the ECU.
Downdraft intake layout and symmetrically aligned intake and exhaust deliver a strong over-run 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.
