Motocross Bikes
2021Kawasaki KX450
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The 2021 Kawasaki KX450 is a competitive motocross bike engineered for serious off-road racers and experienced riders. Its liquid-cooled 449cc four-stroke engine delivers strong power through a manual clutch and five-speed transmission. Known for reliable performance and precise handling, the KX450 remains a top choice for amateur and professional motocross competition.
- Capacity
- 449.0 ccm
- Engine
- Single, four-stroke
- Gearbox
- 5-speed
- Dry weight
- 105.6 kg
- Seat height
- 955 mm
- Power
- 56.0 HP (41.2 kW)
How it rides
Editorial estimate from the spec sheet - not lab tested- Best for
- Built purely for motocross racing on closed circuits, jumps, and rough terrain rather than any form of street use.
- Built for
- A razor-sharp, lightweight, high-revving dirt weapon that rewards aggressive, athletic riding with explosive agility over jumps and rough tracks.
- Not ideal for
- It is not suitable for commuting, touring, passengers, or anyone seeking comfort, storage, or street-legal practicality.
Scores are derived from the spec sheet using the same model across every bike, so they compare like for like.
Will it fit you?
Worked out in your browser - nothing is sent to usEngine
- Capacity
- 449.0 ccm
- Power
- 56.0 HP (41.2 kW)
- Engine type
- Single, four-stroke
- Power/weight ratio
- 0.5303 HP/kg (dry)
- Bore x stroke
- 96.0 x 62.0 mm
- Compression
- 12.5:1
- Cooling system
- Liquid
- Fuel system
- Injection
- Starting
- Electric
- Ignition
- Digital CDI with 3 Coupler Options
- Lubrication system
- Forced lubrication, semi‑dry sump
Transmission
- Gearbox
- 5-speed
- Transmission type
- Manual
- Final drive
- Chain
- Clutch
- Wet multi-disc, manual
Dimensions & weight
- Wheelbase
- 1485 mm
- Overall length
- 2185 mm
- Overall width
- 820 mm
- Overall height
- 1265 mm
- Seat height
- 955 mm
- Dry weight
- 105.6 kg
- Wet weight
- 110.0 kg
- Fuel capacity
- 6.20 litres
- Ground clearance
- 340 mm
Chassis & suspension
- Frame
- Aluminum perimeter
- Front suspension
- 49mm inverted telescopic coil-spring fork with 16-way compression damping and 16-way rebound damping
- Rear suspension
- Uni-Trak® gas charged shock with piggyback reservoir with dual-range (4 turns stepless high speed/19-way low-speed) compression damping, 38-way rebound damping and adjustable preload
- Front wheel travel
- 305 mm
- Rear wheel travel
- 307 mm
- Rake (fork angle)
- 27.6°
- Trail
- 122 mm
Brakes & wheels
- Front brakes
- Single disc. Semi-floating petal discs
- Front brakes diameter
- 270 mm
- Rear brakes
- Single disc. Single-piston caliper.
- Front tyre
- 80/100-21
- Rear tyre
- 120/80-19
Other
- Color options
- Lime Green
Compiled from manufacturer documentation and user contributions, corrected on an ongoing basis. Spotted something wrong? Tell us.
What changed, year to year
Differences highlighted| Specification | 2019 | 2021 | 2023 | 2025 | 2027 |
|---|---|---|---|---|---|
| Capacity | 449 cc | 449 cc | 449 cc | 449 cc | 449 cc |
| Dry weight | 105 kg | 106 kg | 106 kg | 107 kg | — |
| Seat height | 955 mm | 955 mm | 955 mm | 960 mm | 960 mm |
| Fuel capacity | 6.2 L | 6.2 L | 6.2 L | 6.2 L | 6.2 L |
Illustrative - generated automatically by diffing the year records already on file, not a manufacturer-published changelog.
Rider Reviews
Common questions
What is the engine size of the Kawasaki KX450?
The 2021 Kawasaki KX450 has a Capacity of 449.0 ccm (27.40 cubic inches).
What engine power does the Kawasaki KX450 have?
The 2021 Kawasaki KX450 has a Power of 56.0 HP (41.2 kW).
How many gears does the Kawasaki KX450 have?
The 2021 Kawasaki KX450 has a Gearbox of 5-speed.
How much does the Kawasaki KX450 weigh?
The 2021 Kawasaki KX450 has a Dry weight of 105.6 kg (232.8 pounds).
Shop this bike
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The 2021 Kawasaki KX450 is an impressive off-road motorcycle that delivers top-of-the-line performance and handling. With its powerful 449cc engine and lightweight chassis, this bike is sure to please even the most discerning riders. The electric start system and advanced suspension make it easy to navigate through rough terrain, while the slim ergonomics provide a comfortable and natural feel. Whether you're tearing up the track or conquering the trails, the KX450 is a formidable and thrilling ride.
In addition to its outstanding performance, the 2021 Kawasaki KX450 boasts a sleek and aggressive design that is sure to turn heads. The bold graphics and striking color options make for a visually stunning bike that exudes power and speed. With its combination of cutting-edge technology and standout aesthetics, the KX450 is a standout choice for anyone in the market for a high-performance off-road motorcycle. Whether you're a seasoned rider or a newcomer to the sport, the 2021 Kawasaki KX450 is a top contender that delivers on all fronts.
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