The race ready Kawasaki KX 450F proves once more that Kawasaki is ahead of the pack when it comes to building first class motorcycles.

The bike is propelled by a 449 cc, liquid-cooled, four-stroke single engine with DOHC and four-valve cylinder head. The engine transfers its power to the ground by means of a five speed transmission. You also get a 1.64 gallons fuel tank, a high-performance multi-map ECU and launch control.

The ride is kept in check by a Showa SFF-Air TAC fork with triple air chamber and a Uni-Trak rear suspension with SHOWA shock.

The stopping power is handled by lightweight 270mm “oversized” Braking-brand front rotor which is squeezed by a twin-piston caliper and a lightweight 240mm Braking-brand petal-type rear rotor which is gripped by a single piston hydraulic rear caliper.

The Kawasaki KX 450F is offered with a base price of $8,699.

Hit the jump for more information on the Kawasaki KX 450F.

  • 2015 Kawasaki KX 450F
  • Year:
  • Make:
  • Engine:
    Liquid-cooled, four-stroke single with DOHC and four-valve cylinder head
  • Transmission:
  • Energy:
    Digital Fuel Injection (DFI)
  • Displacement:
    449 cc
  • Top Speed:
    75 mph (Est.)
  • Price:


2015 Kawasaki KX 450F Exterior
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Following another highly successful year in competition, improvements to the four-time AMA Supercross Championship-winning KX™450F will keep it on top in 2015!

It’s no secret that Monster Energy Kawasaki has been dominating the AMA Supercross and AMA Motocross series, with Ryan Villopoto piloting his Monster Energy® Kawasaki KX450F-based race bike to four consecutive AMA Supercross Championships in 2011 through 2014. Villopoto’s skills are undeniable, but the race-ready Kawasaki KX450F allows the legendary racer to brake later, carve deeper and accelerate harder thanks to a technology package and powerful yet tractable motor unrivaled by any production motocross bike.

2015 sees the KX450F rise to another level with greater rider adjustability along with chassis, suspension and brake upgrades aimed at maximizing performance for a variety of riders in most every condition. This ensures it is now easier than ever to access the performance of the KX450F and tailor it to fit the rider’s needs.

• Showa SFF-Air TAC Fork with Triple Air Chamber
• High-pressure 300psi digital air pump provided with every purchase
• Uni-Trak® rear suspension with SHOWA shock
• Larger 270mm “oversized” Braking-brand front disc
• Revised Bridged-Box-Bottom piston and ECU programming

2015 Kawasaki KX 450F Key Features:

2015 Kawasaki KX 450F Exterior
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• Launch Control helps to reduce wheelspin on slippery starting gates
• Showa SFF-Air TAC fork with triple air chamber uses air spring to reduce weight, compared to traditional metal-coil fork springs, providing effective tuning and bottoming resistance
• Includes a free digital Kawasaki Genuine Air Fork Pump for quick and easy tuning of fork spring pressure
• Engine is tuned for optimum power delivery all the way from basement revs through the upper RPM range, this results in impressive thrust that continues from corner-exit to the end of the straights
• Revised Bridged-Box-Bottom piston crown increases compression and boosts performance
• Intake cam shape promotes strong low-RPM throttle response
• Larger 270mm “oversized” Braking-brand petal-shape front disc, 240mm petal-shape rear disc
• Front master cylinder features a knocker-style lever-to-piston interface for excellent feel and superbly consistent performance
• Pre-programmed ignition maps are interchangeable trackside, no PC required
• Adjustable 4-position handlebar and 2-position footpegs allow riders to fit the KX to match their personal preference
• Black anodized aluminum rims for a factory look

Engine Overview:

2015 Kawasaki KX 450F Exterior
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• 449cc, liquid-cooled, DOHC, four-stroke single with legendary Kawasaki power!
• Works-based Bridged-Box-Bottom piston has optimum rigidity for maximum high-rpm power and durability
• A forward lean angle of 3° puts the engine in the ideal position for maximum traction
• Highly balanced crankshaft, on par with Villopoto’s factory racer, creates minimal vibration and has a high inertial mass to help maximize rear wheel traction
• Compact cylinder head is only 100mm tall
• Double valve springs help ensure stable valve operation and also allow for a short cylinder head height
• Camshafts, lobes and tappet surfaces feature a soft-nitride treatment for long wear and high-rpm reliability
• Automatic cam chain adjuster is maintenance-free
• Crankshaft and connecting rod feature a special carburizing and quenching treatment to maximize rigidity, boosting long-term reliability without adding weight

Digital Fuel Injection:

2015 Kawasaki KX 450F Exterior
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• Digital Fuel Injection (DFI®) self-adjusts to atmospheric changes for easier starting, sharper throttle response and accessible power for jumping
• It is not necessary to re-tune or change any jets to suit climatic conditions like carbureted models
• Ultra-fine atomizing injector with 12 holes sprays particles with a droplet size of 60µ for smooth power delivery and engine response throughout the throttle range
• 43mm throttle body uses a progressive throttle linkage to deliver airflow in much the same way as an FCR carburetor
• Using two linked shafts, the throttle body opens more quickly after reaching the 3/8 open position
• Fast-idle knob on the throttle body allows riders to increase engine speed when starting a cold engine
• Fuel injector set at 45°, the optimum angle for mid-range power

High-Performance Multi-Map ECU:

2015 Kawasaki KX 450F Exterior
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• Revised ECU programming enhances traction by retarding ignition when excess wheelspin is detected by a sudden surge in RPM.
• Ignition timing boosts response when re-opening the throttle after deceleration (when landing jumps, etc.)
• ECU programming is easily selectable via interchangeable DFI coupler caps that provide three preprogrammed maps for standard, hard (terrain) and soft (terrain), without the need for a separate programmer or laptop
• The engine can be started with only three rotations of the crankshaft using the electricity generated by a single kick of the starter, no battery needed
• The system delivers electricity to the bike’s electronics in sequence: first the ECU, then the fuel pump, and finally the injector for quick, easy starting
• The compact, lightweight ECU, located on the front of the steering head behind the number plate, was designed specifically for motocross use. The fuel pump relay is integrated with the ECU to help cope with the shocks and vibrations of tough racing

Launch Control Mode:

2015 Kawasaki KX 450F Exterior
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• Factory-style launch control system is an industry first and increases the ability to get good starts by maximizing available traction
• Push-button activation of the Launch Control Mode retards ignition timing in first and second gears, giving the greatest effect within the first few seconds of releasing the clutch
• Launch Control can be activated in neutral, first or second gear
• Shifting into third gear automatically deactivates Launch Control Mode and returns the ignition to normal mapping

Easy Starting:

2015 Kawasaki KX 450F Exterior
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• Strong output from the large ACG rotor provides enough electrical power for the battery-less FI system to enable true one-kick starting without using a battery
• Equipped with an automatic compression release (ACR) system for quick and easy starting. The dual-weight centrifugal decompression system is fitted to the exhaust cam
• Compression release features 1.0mm of valve lift, to minimize the required kicking power

Bridged-Box Bottom Piston:

2015 Kawasaki KX 450F Exterior
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• Piston crown shape tuned for excellent low to mid-range engine response
• Same design as used on our factory racers; offers optimum performance at all rpm
• Lighter and more durable than traditional piston designs
• Short piston skirt features low-friction coating to minimize mechanical losses
• Reinforced external ribs enhance strength and durability

Showa SFF-Air Front Fork:

2015 Kawasaki KX 450F Exterior
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• Showa SFF-Air TAC fork with triple air chamber uses air as a spring. The reduced weight and inertia of the air spring improves smoothness and enhances the fork’s ability to follow terrain contours
• Air spring significantly reduces friction and cuts weight while also providing better bottoming resistance, less oil contamination, plus easier and more effective tuning compared to traditional springs
• Large diameter internal damping cartridges help provide consistent performance and bottoming resistance
• A removable spring pressure adjustment valve and free 0-300psi digital Kawasaki Genuine Air Fork Pump are included for quick and easy tuning of fork spring pressure
• Hard titanium coating on the outer surface of the inner fork tubes offers minimum stiction when the fork is exposed to lateral forces that would usually hamper slide action. The result is improved fork response, especially during cornering
• Friction-reducing Kashima Coat on the inside of the fork’s outer tubes contributes to smooth suspension action (especially at the initial part of the stroke)
• Wrap-around fork tube guards offer effective protection for the sliders
• Lower triple clamp features integrated locating pins to help simplify installation and removal of the front number plate
• One-piece front fender attachment screws feature integrated grommets to simplify installation and removal

Rear Shock:

2015 Kawasaki KX 450F Exterior
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• 22-position rebound damping adjuster allows precise fine-tuning of the rebound circuit
• Easy adjuster access allows track-side suspension tuning with a minimum of hassle or lost time
• Rear shock features dual compression adjustability, allowing 19-position low-speed and 4 turns of high-speed damping adjustments to be made independently

Aluminum Swingarm:

2015 Kawasaki KX 450F Exterior
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• Tapered “D” shape swingarm is lighter than a comparable box-section unit and provides superior rigidity for its weight
• Features tapered hydroformed spars and forged chain adjusters
• Uni-Trak® rear suspension linkage is mounted below the swingarm to allow precise tuning and maximum rear suspension stroke

Fuel Tank and Lightweight Aluminum Fuel Pump:

2015 Kawasaki KX 450F Exterior
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• Compact 1.6-gallon fuel tank is formed using a blow molding process
• Fuel pump features a one-piece filter cover and body, eliminating the need for fuel return tube from pressure regulator
• Features a plastic fuel filter cover that wraps around the inlet port and acts as a fuel trap to help ensure a stable fuel supply during vigorous motocross riding

Efficient Cooling:

2015 Kawasaki KX 450F Exterior
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• High-capacity Denso radiators feature tightly packed cores and a fin design that deliver superior cooling efficiency
• Shroud shape features a slim profile and large cooling outlet hole to help keep excess heat to a minimum
• Radiator louvers feature four small blades set at a shallow angle for minimum overlap and maximum air flow

Strong and Durable Clutch:

• Clutch assembly provides a direct feel and superb control of engagement
• Excellent oil drainage reduces power loss caused by excess oil around the clutch basket
• Friction plates with substantial friction material contribute to fade resistance and long service life
• Clutch case cover features embossed logo and is painted silver, making scuffs and normal wear less noticeable

Close-Ratio 5-Speed Transmission:

• 5-Speed transmission and the engine’s broad torque curve gives riders more gear options for maximum drive on a wide range of tracks
• Thick first gear offers excellent durability for launching off the line in high-traction situations

Powerful Disc Brakes:

• Front master cylinder features a knocker-style lever-to-piston interface for excellent feel and superbly consistent performance
• Front brake pads offer a strong braking force and feel
• Lightweight 270mm “oversized” Braking-brand front rotor is squeezed by a powerful twin-piston caliper and features an aggressive petal design to help clear mud and debris
• Lightweight 240mm Braking-brand petal-type rear rotor features the same aggressive petal style as the front rotor and is gripped by a single piston hydraulic rear caliper

Rider Interface and Styling:

• Slender frame helps the bike feel compact and nimble, but tapers to become wider near the rider’s ankles to offer optimum grip and control
• Wide 50mm footpegs can be adjusted to alternate position, 5mm lower than stock
• Dual injected 2-tone, one-piece plastic shrouds and side number plates are great looking, compact and lightweight
• Black triple clamps and black anodized rims – just like Kawasaki’s factory teams
• Green finish on suspension adjusters and engine plugs look like the factory race parts
• Slim seat design uses urethane foam designed to retain its original shape and provide optimum durability

Additional Features:

• Skid plate made of resin material offers great protection without excess weight
• Clutch cable boot features a large quick adjuster, making it easy for riders to adjust clutch play on the fly
• Rear caliper guard helps protect the caliper from damage
• Ribless rear hub and butted spokes offer light weight and excellent durability
• New lightweight axles are lighter by 31 grams front and 32 grams rear

Optional KX Accessories:

• Kawasaki Racing Software Kit allows racers to reprogram the ECU’s data maps for volume of fuel injected and ignition timing to alter engine characteristics to suit rider preference. An ECU setting is available, which can also be used as a data logger, recording up to six hours of data, including engine rpm, degree of throttle opening, engine boost, coolant temp, air temp, ignition timing, fuel adjustments, gear position and system voltage


Engine Liquid-cooled, four-stroke single with DOHC and four-valve cylinder head
Displacement 449cc
Bore x stroke 96.0 x 62.1mm
Compression ratio 12.8:1
Fuel system DFI® with 43mm Keihin throttle body
Ignition Digital DC-CDI
Transmission 5-speed
Final drive Chain
Frame type Aluminum perimeter
Rake / trail 27.9 degrees / 4.7"
Fuel capacity 1.64 gallons
Front suspension / wheel travel Inverted Showa SFF-Air TAC fork with Triple Air Chamber, DLC coated sliders, 22-position compression and 20-position rebound damping adjustment / 12.4"
Rear suspension / wheel travel Uni-Trak® linkage system and Showa shock, 19-position low-speed and 4-turns high speed compression damping, 22-position rebound damping and fully adjustable spring preload / 12.4"
Tire size, front 80/100-21
Tire size, rear 120/80-19
Brakes, front Single semi-floating 270mm Braking® petal disc with dual-piston caliper
Brakes, rear Single 240mm Braking® petal disc with single-piston caliper
Overall length 86.4"
Overall width 32.3"
Overall height 50.2"
Ground clearance 13.4"
Seat height 37.8"
Curb weight 247.1 lb
Wheelbase 58.8"
Color choices Lime Green
Price $8,699
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