With more Supercross and Motocross championships than any other manufacturer, the KX name is synonymous with winning. The KX450 motorcycle represents the flagship of the KX lineup, built with the sole purpose of dominating the track. Over the past four decades, we’ve learned what it takes to win and stay on top. Our dedication to building the ultimate machine is undeniable, and the KX450 represents this to the fullest.

Built to Win

The KX™450 engine delivers broad, useable torque and strong, responsive power across the rev range. From the starting gate to the finish line, this race-ready machine is built to stay ahead of the pack.

Power Through The Finish

The powerful 449cc engine features friction reduction coating on the piston for increased engine performance.

Every Second Counts

A factory-style launch control system helps put the bike’s power to the ground for maximum acceleration at the start of the race, making the holeshot yours for the taking.2020 model shown.

Pull Ahead

A flat torque curve makes it easier to get on the gas sooner, delivering smooth and powerful acceleration to pass the competition and keep you ahead of the pack.

Finely Tuned Power

Use the DFI couplers to choose engine settings to suit your riding style or track conditions. This plug-and-play style system allows quick and easy selection from three pre-programmed fuel injection and ignition mapping settings. Fine tune your ECU setting with factory precision. The KX™ FI Calibration Kit* features a handheld controller that enables adjustment of fuel mapping and allows storage of presets without a PC.*Sold separately as a Kawasaki Genuine Accessory

Leave Them in the Dust

Take the lead with proven race-winning performance. The highly adjustable suspension package delivers smooth action, firm damping and contributes to optimal traction.

Race Ready

The 49mm Showa Coil Spring Front Fork combined with A-KIT Technology deliver excellent handling. Large-diameter inner tubes allow the use of large damping pistons for race-winning performance while a large-diameter front axle provides exceptional front-wheel traction.

Championship Proven

The Uni-Trak rear suspension system features adjustable dual-range (high- and low-speed) compression damping, adjustable rebound damping, and adjustable preload. The result is optimal damping and rear-wheel traction.

Ride With Confidence

From quick, reliable starting to advanced braking power, the KX™450 motorcycle offers superior features designed to inspire confidence. What’s more, this race-ready machine is backed by decades of championship-proven experience.

Advanced Stopping Power

Next-level stopping power matches incredible acceleration capability. Up front, an oversized 270mm Braking petal disc with dual-piston caliper offers sharp response and a strong, consistent feel. In the rear, a large-diameter 250mm Braking petal disc complements the front for race-ready performance.

Reliable Starting

Being able to restart your engine quickly after a stall can make or break a race. Powered by a compact and lightweight Li-ion battery and supported by an automatic centrifugal decompression system, all it takes is the push of a button to start up.

Light Pull & Self-Adjusting

A coned disc-spring hydraulic clutch offers light clutch pull and a wide engagement range. Large diameter plates provide enhanced fade resistance.

Made To Shave Lap Times

Experience the race-winning advantage of a strong and lightweight chassis, agile handling and exclusive ERGO-FIT technology.

Balance Meets Precision

A lightweight aluminum perimeter frame and swingarm provide overall rigidity balance, contributing to precise cornering. Front-end feel is predictable and maximum traction is gained at the rear wheel.

Get a Grip

Wide footpegs ensure excellent grip for optimum comfort and control, and make it easier to weight the pegs.

Perfect Fit

Find your best performance with the Kawasaki ERGO-FIT advantage. Four handlebar positions and two footpeg positions allow you to tailor the KX™450 motorcycle to your body size, riding style and preference.

Renthal Fatbar Handlebar

A factory-style aluminum Renthal Fatbar handlebar comes standard. With grips positioned low and close to the body, riders can shift weight forward easily to improve front wheel traction, and increase front traction feel, to ride more confidently at the limit.


  • Engine

    4-stroke Single

  • Displacement

    449 cm3

  • Bore x Stroke

    96.0 × 62.1 mm

  • Compression Ratio


  • Valve System

    DOHC, 4 valve

  • Fuel System

    Fuel injection (o44 × 1)

  • Ignition


  • Starting


  • Cooling


  • Lubrication

    Forced lubrication, semi-dry sump

  • Transmission

    5-speed, return

  • Primary Reduction Ratio

    2.727 (60/22)

  • Gear Ratio: 1st

    1.750 (28/16)

  • Gear Ratio: 2nd

    1.412 (24/17)

  • Gear Ratio: 3rd

    1.188 (19/16)

  • Gear Ratio: 4th

    1.000 (19/19)

  • Gear Ratio: 5th

    0.875 (21/24)

  • Final Reduction Ratio

    3.846 (50/13)

  • Clutch

    Wet multi-disc, manual

  • Final Drive



  • Frame

    Perimeter, aluminium

  • Front Suspension

    49 mm inverted telescopic fork with adjustable compression and rebound damping

  • Rear Suspension

    Uni Trak with adjustable dual-range (high/low-speed) compression damping, adjustable rebound damping and adjustable preload

  • Front Wheel Travel


  • Rear Wheel Travel


  • Rake


  • Trail


  • Steering Angle (L/R)

    42? / 42?

  • Front Tyre

    80/100-21 51M

  • Rear Tyre

    120/80-19 63M

  • Front Brake/s

    Single semi-floating o270 mm petal disc

  • Front Caliper/s


  • Rear Brake

    250 mm petal disc

  • Rear Caliper



  • Dimensions (LxWxH)

    2185 × 820 × 1265

  • Overall Length


  • Overall Width


  • Overall Height


  • Wheelbase


  • Road Clearance


  • Seat Height


  • Curb Mass

    110 kg

  • Fuel Capacity


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