
2012 KX450F riders can easily activate the new Launch Control mode – a key feature never before seen on a production motocross bike. The push-button system is activated by a touch of the switch on the left handlebar, and optimizes off-the-line acceleration by altering ignition timing in first and second gears to help maximize grip and reduce the chance of excessive wheelspin. Shifting into third gear automatically deactivates Launch Control Mode and returns the ignition timing to the parameters of the installed ignition map. The Launch Control’s effectiveness is further enhanced by a chassis designed to maximize suspension performance and rear wheel traction.

The KX450F delivers improved mid- to high-end power and a wider powerband, thanks to numerous upgrades. The KX450F’s race-proven bridge-box bottom piston allows for optimum strength just like last year, but has been revised to optimize its rigidity balance and enhance mid- high-rpm character. A new thinner top piston ring with upgraded surface treatment reduces friction and helps improve throttle response. A new intake cam offers a slight increase in intake valve lift and allows the motor to breathe deeper, boosting power as well. The resulting combination offers a wider spread of torque and increased high-rpm performance. That extra power makes it to the ground more effectively than ever, thanks to the new electronics, plus multiple transmission upgrades and chassis improvements designed to complement the bolder power delivery.

The Kayaba rear shock features a beefy 50mm piston and also receives a top-shelf Kashima Coat surface treatment in its internals. Ample adjustability of the shock body helps ensure smooth, reliable and consistent action of the rear suspension that not only offers superior performance, but also helps the rider relax and conserve valuable strength on the way to the finish line.
The new fuel tank has a shorter overall height and a narrower top section, which forms a straighter, smoother line with the seat and allows greater freedom of movement for the rider. The new fuel tank also houses an upgraded fuel pump, which is lighter in weight thanks to an integrated filter cover which wraps around the inlet port and acts as a fuel trap. This also eliminates the need for a pressure regulator fuel return hose.

The new header pipe has a shorter length and features a tapered mid-section. The new silencer is a full 60mm shorter than its predecessor, but features a revised cross-section and the same overall volume as the 2011 model and meets noise regulations.
A new rigid-mount wave-type front brake rotor, slimmer front tire and new seat foam add to the lengthy list of improvements made to the 2012 KX450F. Minimalist body work, revised shrouds and smaller number plates contribute to the slender feel and sleek new looks of Kawasaki’s flagship motocross machine. Sparing no attention to detail, the seams between the radiator shrouds, seat and side covers are very flush fitting, which helps prevent snags and allow the rider to alter position and maneuver the bike more effectively.
A blue alumite finish on the oil cap and two caps on the generator cover highlight the upgraded appearance of the KX450F motor, and match the blue finish on the suspension adjusters and splashes of color in the new graphics. A new embossed logo on the clutch cover features a trick design that reveals a raised Kawasaki racing insignia as the black paint is worn away by the rider’s boot.
2012 Kawasaki KX™450F
At a glance…
All-new Launch Control Mode increases the chance of nailing the holeshot
New pre-programmed ignition maps, interchangeable trackside, no PC required
Upgraded engine with more top-end thrust and a wider powerband
New adjustable bar and footpeg positions
New slimmer frame and minimalist bodywork
Upgraded transmission for easy, reliable shifting
New pipe and silencer help centralize mass
50mm AOS forks with DLC coated inner fork tubes
Black Alumite coated rims

Engine Overview
449cc liquid-cooled, DOHC, four-stroke single
Works-based Bridged-box Bottom piston has revised rigidity for improved high-rpm power
Revised intake cam and all-new exhaust result in wider powerband
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
Maintenance-free automatic cam chain adjuster
Large airbox flap helps prevent mud and water from entering
Bridged-box Bottom Piston
Thinner top ring and revised surface treatment of oil ring reduce friction
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
Compact head is only 100mm tall
Intake camshaft profile revised to increase intake for better low- and mid-range power
36mm titanium intake and 31mm exhaust valves with aluminum spring retainers minimize reciprocating weight and cylinder height to help ensure reliable valve control at high rpm
Double valve springs allow a short cylinder head height and help ensure stable valve operation
Camshafts, lobes and tappet surfaces feature a soft-nitride treatment for long wear and high-rpm reliability

Crankshaft
Crankshaft with high inertial mass helps maximize rear wheel traction
Wedge-shaped crank web provides enough offsetting moment for a 60 percent balance factor – and is similar to the crank balance in Kawasaki’s factory race engines
Net result is reduced engine vibration, smoother power delivery and increased performance, with a noticeably snappier response at low rpm
Crankshaft and connecting rod feature a special carburizing and quenching treatment to maximize rigidity
Digital Fuel Injection
Self-adjusts to atmospheric changes for easier starting, sharper throttle response and optimized power and stability when jumping/landing
It is not necessary to re-tune, or change any jets to suit climatic conditions like on a carbureted model
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
Factory-style launch control system increases chance of getting a good start by maximizing traction on a slippery surface
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 deactivates Launch Control Mode and returns the ignition to normal mapping
System is designed to same specifications as factory Kawasaki AMA machines

High-performance ECU
New ECU programming offers three preprogrammed maps: Standard, Hard (conditions) and Soft (conditions)
Maps are now easily selectable via DFI wire coupler caps, no computer necessary
No battery needed; the engine can be started with only three rotations of the crankshaft using the electricity generated by a single kick of the starter
The system delivers electricity to FI system 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 motocross riding
Optional User ECU Setting Tool
KX FI Calibration 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
The tool 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
2012 software program is updated for compatibility with 64-bit operating systems such as Windows 7
Easy Starting
Revised shape of kickstart ratchet enables lever to return to start position more smoothly
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
Lightweight Aluminum Fuel Pump
Fuel pump now features a one-piece filter cover and body, eliminating the need for fuel return tube from pressure regulator and contributing to weight reduction
Features a plastic (formerly rubber) 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
New 1.6-gallon fuel tank is formed using a blow molding process
Efficient Cooling
High-capacity Denso radiators feature tightly packed cores and a fin design that deliver superior cooling efficiency
Changed left side radiator upper pipe angle for new shroud design
New shroud shape features a slimmer profile and larger cooling outlet hole
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
Heavier clutch springs give a more positive feel to the rider
Excellent oil drainage contributes to more direct feel
Friction plates with substantial friction material contribute to a direct feel
New clutch case cover features embossed logo, designed to be revealed as rider’s boot wears away black paint
Close-Ratio 5-Speed Transmission
5-Speed transmission and low-rpm engine response combination offers riders more gear options for traversing rough sections or getting into the rhythm of a course easily so they can focus more on racing
Revised number of gear dogs (3 dogs/3 holes to 4 dogs/4 holes) improve shift feel
Thicker first gear offers greater durability for launching off the line
Shorter shift fork (5.3mm to 4.4mm) reduces the shift force necessary to change gears
New shift lever moves the pedal 3mm farther from the footpeg and offers greater durability
New polyurethane resin drive chain roller reduces weight
Exhaust
New tapered header pipe is shorter in length and features a smaller overall diameter
Tapered mid-piece is new for 2012 KX450F
New silencer is 60mm shorter, but thanks to a new cross-section, features same overall volume as ’11 model to help meet current 94dB noise regulations
Powerful Disc Brakes
New front disc features an aggressive petal design
Powerful twin piston hydraulic front caliper squeezes 250mm rotor
Lightweight rigid-mounted front disc reduces unsprung weight by 80 grams
Single piston hydraulic rear caliper squeezes lightweight 240mm petal-type rotor
Light, Slim Chassis
New main frame spars are 4mm slimmer to help reduce overall width at the rider’s knees
Increased rigidity in the swingarm bracket area helps increase rear wheel traction and provide a more solid feel when landing jumps
Aluminum Swingarm
Cross-section design contributes to light handling
Tapered “D” shape swingarm provides ideal rigidity for excellent stability, and is lighter than a comparable box-section unit
Alloy swingarm features a cast front section, tapered hydroformed spars and forged chain adjusters
Uni-Trak® rear suspension linkage altered for improved traction, utilizing a revised tie-rod unit which is less rigid
Suspension arm is mounted below the swingarm to allow a longer rear suspension stroke and more precise tuning
New optional linkage tie rod is 1mm shorter, creating a 6mm reduction in seat height for shorter riders
AOS Front Fork
Race-oriented suspension settings offer maximum overall performance
Revised lower triple clamp locates the clamp opening in the rear as opposed to the side for increased rigidity and improved fork action
Kayaba Air-Oil-Separate (AOS) fork keeps oil and air in separate chambers for stable damping performance during long motos. Low-friction fork seals contribute to smooth action
Diamond-Like Carbon (DLC) 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) and a superb ride feel
Wrap-around fork tube guards offer effective protection for the sliders
Rear Shock
Rear suspension settings and linkage ratios derived from extensive rider testing
Kayaba rear shock features a large 50mm piston
Rear shock features dual compression adjustability, allowing high-speed and low-speed damping to be tuned separately
Also features Kashima Coat treatment on the cylinder for reduced friction and smoother suspension action
Easy adjuster access for track-side suspension tuning
Rider Interface and Styling
Dual injected 2-tone, one-piece plastic shrouds and side number plates minimized for mass centralization and rider comfort
Upgrades bodywork features more flush seams for easier rider movement
Lower-capacity fuel tank is shorter and narrower, creating a straighter line from the seat
Black plastic covers, triple clamps, engine covers, and black alumite-coated rims – just like Kawasaki’s factory teams
Blue alumite finish on suspension adjusters and engine plugs match new graphics accents
Wide 50mm footpegs can be adjusted to alternate position, 5mm lower than stock
Frame is wider at the ankles to offer optimum grip, narrows below the seat to allow a slim riding position
Slim seat design uses new urethane foam designed to retain its original shape longer
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 play in the clutch cable on the fly
Rear caliper guard helps protect the caliper from damage
Ribless rear hub and butted spokes offer light weight and excellent durability
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