2012 Kawasaki Motocrossers Feature New Tech – Dual Injectors and Launch Control

May 17, 2011


Kawasaki 2012 KX250F

Kawasaki and Ryan Villopoto wrapped up the 2011 Monster Energy Supercross championship, both an AMA and an FIM World championship, just a couple of weeks ago in Las Vegas with the 2011 KX450F.  Kawasaki has just announced the redesigned 2012 KX450F and its little brother, the KX250F.  The KX250F has its share of championships, as well, including the Western Region Supercross Lites title Broc Tickle earned the same evening in Las Vegas.  We have tested the KX250F several times (most recently, the 2011 model here).

Not resting on its laurels, Kawasaki has substantially redesigned both motocross bikes for 2012, and included groundbreaking technology in each model.  The 2012 KX250F features not one, but two fuel injectors that work in tandem, including one placed inside the airbox.  Meanwhile, the 2012 KX450F gains a rider-selectable launch control aimed at improving traction, and reducing wheel spin, in first and second gears.  The system automatically disengages the first time the rider selects third gear.

Both bikes have numerous, additional changes to both chassis and engine, as well as transmission, for 2012, all of which are detailed in the following press releases from Kawasaki.

2012 KAWASAKI KX™250F - Kawasaki Innovation Continues with Dual Injectors

No other bike in its class has spent more time on the AMA Supercross podium than the Kawasaki KX™250F. The race-proven technology of the quarter-liter motocross leader returns for 2012, but with added enhancements that give the KX250F even more usable power, increased durability, and the best-handling chassis yet.

As the KX250F continues to lead the way in stadiums, it also continues to win the favor of enthusiast publications, who repeatedly name it a gold standard in motocross machinery. The KX250F offers cutting-edge technology right off the showroom floor, to give riders the winning edge on the track. Along with the KX250F’s race-proven performance, no other production motocrosser offers as much adjustability, fine-tuning capabilities and rider customization when it comes to motor and suspension. Right off the production line, the KX250F gives a factory advantage to the privateer racer – the difference between scratching for a podium and dominating a championship.

Second injector located in air boot.

For 2012, Kawasaki engineers sought to create a KX250F with even more impressive top-end performance, which they accomplished by equipping its Digital Fuel Injection (DFI®) system with a second fuel injector –a first for use on production motocross bikes– located near the airbox intake. The all-new “upstream” injector helps build a wider and more potent spread of power as rpm climbs. The two fine-mist atomizing injectors that feed the 250cc four-stroke powerplant are distinct in appearance with different body sizes, but deliver the same per-cycle capacity. Together, Kawasaki’s dual injectors pack a one-two punch, delivering a second dose of fuel on acceleration to increase the high-rpm power and overrev capabilities of the KX250F.

The addition of the second injector led to multiple modifications to the DFI system. An updated Electronic Control Unit (ECU) harnesses increased ignition power to run the DFI system. An accessory 2012 calibration kit is available and uses the same connector design as 2011, but features upgraded software and is compatible with Windows 7.

The 43mm Keihin throttle body is fitted with a new seal between the air inlet port and throttle position sensor unit designed to prevent fuel penetration from the upstream injector. The 2012 KX250F is also fitted with an air boot specifically altered to allow room for the upstream injector.

The dual-injector system is the central highlight of revisions made to the 2012 KX250F, but engineers didn’t stop there in their efforts to hone this 250cc masterpiece. A host of subtle changes throughout the motor continue to make it stronger and more durable throughout, all without weighing heavily on the price tag!

An upgraded crankshaft with redistributed inertial balance harmonizes with the more potent power delivery and also helps improve reliability. The bridged box-bottom piston and cylinder walls both feature new surface treatments to minimize wear and enhance long-term durability.

Modifications to the crankshaft, connecting rod, ACG stator and rotor change their rotational inertia, enhance durability and help provide a masterful balance to the high-performance engine. Overall, the crankshaft assembly features a balance factor of nearly 60 percent, which is right on par with factory Kawasaki race machines.

The seamless power delivery of the upgraded engine and DFI system is supplemented by a handful of transmission upgrades. A slightly shorter stroke of the shift fork and solid (rather than hollow) more smooth shift rods give the rider a more positive feel when changing gears, while keeping shift action as silky smooth as ever. The smooth-shifting transmission and reliably consistent clutch help keep the engine in the thick of its powerband throughout even the most challenging laps.

Sharp new styling touches enhance the appearance of the upgraded powertrain. The oil filler cap and engine plugs are colored blue, matching blue accents on the suspension adjusters and stylish new graphics.

Following the success of the 2011 KX250F and its impressive Separate Function Fork (SFF), the front suspension on the 2012 machine could have remained entirely untouched and still been a class leader. However, never content to leave exceptional alone, Kawasaki engineers analyzed feedback from the race teams and massaged the second-generation SFF accordingly.

Separate function fork

Fork spring rate is higher for 2012, going from a 9.1N/mm to a 9.5N/mm. A new, longer rebound spring improves corner approach and offers a more supple initial feel. In the left fork tube’s damper stack, the valving has been adjusted to complement the heavier spring rate. Two key features that retained from last year are the external fork preload adjuster and the trick titanium coating on the outer surface of the inner fork tubes.

The Showa-built shock also receives a stiffer spring rate, advancing from 51N/mm to 53N/mm. Along with a re-valve on the shock body, the compression damping restrictor and piston rod specs have been enhanced to refine the action of the shock. Complementing the shock upgrades is a thinner tie-rod on the suspension linkage with less rigidity, for smooth suspension action and improved traction. These refinements improve rear wheel traction and allow the KX250F to put the power down more effectively, making it easier than ever to grab the holeshot.

The KX250F is frequently praised for its rider interface and natural layout that fits a variety of sizes and abilities. Sleek and attractive bodywork includes a one-piece shroud and number-plate design. For 2012 the KX250F receives a new polyurethane seat that is more resistant to wear. The remainder of the chassis retains its finely crafted balance allowing the rider to have optimum leverage at all contact points for maximum performance gains on the track.

The KX250F is finished with quality race-proven components such as a Renthal aluminum handlebar and black alumite-coated aluminum wheels that are both lightweight and incredibly strong. A sleek, ribless rear hub and butted spokes further reduce unsprung weight, and factory-style graphics with a splash of blue that matches the alumite suspension adjusters and engine plugs finish off the sophisticated look of the class-winning machine, which is bound to top plenty of race podiums and enthusiast publication shootouts in the coming year.

Racers who ride their KX250F at designated events are eligible to receive support from Team Green™, Kawasaki’s amateur racing support program. Each year, Team Green provides regional support vehicles and highly trained technicians at more than 100 events throughout the United States, offering technical information and assistance to those who race Kawasaki products. Kawasaki also offers a comprehensive contingency program for amateur and professional riders who place well at designated events.

Authentic Kawasaki Accessories are available through Kawasaki dealers.

2011 Kawasaki KX™250F

Features and Benefits

At a Glance…

New dual injector Digital Fuel Injection systemMore robust high-rpm engine output extends deep into the overrevRevised transmission offers improved shifting action and durabilityThicker, stronger engine components improve reliabilityRevised Showa Separate Function Fork (SFF) offers more supple initial hit, and improved action during corner entryIncreased spring rates on front and rear suspension enhance traction and offer a more solid feel

High-revving, High Performance Engine

249cc, liquid-cooled, four-stroke, four-valve, single-cylinder DOHC engine delivers hard-hitting power across the rpm rangeImproved decompressor spring action for easier startingNew nickel plating on cylinder walls has a higher adhesion factor for increased durabilityNew connecting rod has a thicker stem for improved reliabilityNew more rigid crankshaft is re-balanced for better performance and higher durabilityThicker crank web design features a balance factor on par with the factory racers for reduced engine vibration, smoother power delivery and increased performance in the mid-high rpm rangeRevised ACG stator and rotor inertia complements the changes made to the crankshaft

Digital Fuel Injection (DFI) System

Upgraded system adds a new “upstream” injector located closer to the airboxAll-new second injector features different body size, but same capacity as primary injectorAdded seal between air inlet port and throttle position sensor unit on the 43mm throttle body protects TPS sensor from fuel penetrationProgressive throttle linkage opens more quickly after 3/8 open positionSimple and efficient system: No battery, fuses or relaysSharp and precise engine response across entire rpm rangeOffers easy engine startingHelps prevent engine hesitation after landing from jumps and other high-impact situationsOptional accessory calibration Kit features new 6-pin connector type allows easy tunabilityOptional accessory FI Indicator Light allows the DFI system to communicate diagnostic information

Bridged Box-Bottom Piston

Light and strong piston shares same design as the factory racers, with a new tin plating to optimize its interface with the new nickel plating on the cylinder wallChanged shape of streak finish improves lubrication and wear resistance Short piston pin reduces reciprocating weight

Lightweight and Efficient Top End

Lightweight, highly rigid, titanium 31mm intake and 25mm exhaust valves reduce reciprocating weight and offer high-rpm reliabilityUltra-light valves have extremely thin valve stems on par with those found in supersport machines; intake valves feature thick heads for increased strengthIntake ports designed for peak performance at all rpm, especially in the high-rpm rangeSpecial casting method leaves the intake port surfaces extremely smooth for optimum intake efficiency across the rev rangeSilicon-coated head gasket provides excellent sealing

Stainless Steel Exhaust System

Stainless steel construction offers extra durabilityHigh-volume muffler assembly keeps noise levels at 94 dB while retaining power productionJoint between pipe and muffler offers excellent sealing, while a rubber damper collar on the rear silencer mount equals serious durability

Efficient Cooling System

Thick and wide radiators are strong and offer excellent resistance to mud buildup while providing superb cooling performanceCylinder head water jacket routes coolant to the front of the cylinder head for even cooling

Transmission and Shifting

Shorter shift fork stroke and more smooth solid shift forks (not hollow) offer improved shifting actionStrong, beefy crankcases feature additional material around the engine mounts to help increase long-term durabilityClutch cable holder is integrated with the crankcase for accurate feel at the clutch leverScavenge oil filter screen can be accessed without splitting the crankcases, facilitating easier maintenance

Quick-turning Chassis

Utilizes a low-rigidity steering stem for lighter handlingThe KX250F’s slim and lightweight aluminum perimeter frame is composed of forged, extruded and cast partsCenter of gravity and key dimensions such as swingarm pivot, output sprocket and rear axle locations designed to increase forward drive with minimal rear-end squatUpper engine mounts on head cover sides increase overall rigidity

Race-oriented Suspension

Revised race-oriented suspension features heavier spring rates and revised damping settings both front and rearSeparate Function Fork (SFF) separates springing and damping functions for less weight, better performance, less stiction and easier adjustabilityFork features the only external spring preload adjustability in its classSuper-hard titanium coating on the outer surface of the inner fork tubes reduces stiction and improves suspension action while also helping prevent scratches and tube damageFriction-reducing Kashima Coat treatment on the inside of the outer fork tubes contributes to smoother suspension actionWrap-around fork tube guards provide greater protection for the inner tubesAltered piston rod specs improve shock setting flexibility and offer better rear wheel tractionFeatures Kashima Coat on the inside of the shock reservoir for reduced friction and smoother suspension actionRear shock features dual compression adjustability, allowing high-speed and low-speed damping to be tuned separately

Superior Rear-wheel Traction

Swingarm features optimum internal bracing and flex characteristics for superb cornering performanceAlloy swingarm uses a cast front section, tapered hydroformed spars and forged chain adjustersUni-Trak® rear suspension linkage system mounts the suspension arm below the swingarm, allowing more rear suspension stroke and precise tuningLinkage system receives upgraded tie-rod which has less rigidity for smoother suspension action and improved tractionLinkage ratios for the Uni-Trak rear suspension match rear shock damping settings to achieve maximum rear wheel traction

Rider Interface

Bodywork components offer the rider a slim interface, making it easy for racers to feel comfortable and go fastFormed using a double-injection molding process, the two-tone shrouds offer a slim designSide number plates also two-toned and contribute to the slim packageRight side panel has an added passageway to help cool the silencerFrame is wider at the ankles to offer better grip and narrows near the bend below the seat to allow a slim riding positionSlim seat features upgraded polyurethane, designed for greater durabilitySeat has a slip-resistant top and side surface for good grip when seated and while standing50mm wide (front-to-rear) footpegs offer superb grip and feel at the pegsClutch cable boot features a large quick adjuster, making it easy for riders to adjust play in the clutch cable while on the flyThrottle grip has a one-piece collar that provides additional stability during throttle operationLightweight short-length grips feature a pattern designed to provide excellent grip

Factory-style Components

Black alumite-coated rims, just like the factory racersTitanium coated inner fork tubes to minimize stictionLightweight rims offer maximum strength and weight savingsThick and rigid front fenderRear brake pad material offers powerful braking performanceFront and rear petal brake discs help reduce unsprung weight, and the wave shape helps clean the brake pads for more efficient stopping performanceRear caliper guard protects caliper from damageRibless rear hub and butted spokes further reduce unsprung weightRenthal aluminum handlebar is standard equipmentBlue ignition cover plugs and oil filler cap match the blue accents on the factory race bikesFactory-style graphics complement the KX250F’s highly tuned performance

Additional Features

New countershaft sprocket cover improves lookNew polyurethane resin drive chain roller reduces weightRedesigned air boot allows room for second fuel injectorLarge resin skid plate offers great protection with minimum weight

Optional Accessories

Optional DFI Calibration Kit allows custom tuningOptional FI Indicator Light allows the DFI system to communicate diagnostic informationOptional engine parts include magneto rotors with different inertias and a 12-tooth output sprocketOptional chassis parts include handlebar holder for a 1 1/8-inch handlebar, 46- to 50-tooth aluminum and steel rear sprockets, solid petal brake rotors, different fork and shock springs and manual decompression lever and cable

2012 Kawasaki KX250F Specs

Kawasaki 2012 KX450F

2012 KAWASAKI KX™450F - Prepare for Launch…

The race-winning power and confident handling of Kawasaki’s KX™450F motocrosser are back in an even sleeker and more advanced package than ever before. With racing always at the forefront, the KX450F’s latest technical innovations were developed from the factory know-how of the Monster Energy Kawasaki race team, with the final product representing an unmatched combination of cutting-edge innovation and race-proven components. Its best-in-class performance is facilitated by the highest level of rider adjustability and the most progressive electronics package ever seen on a production motocrosser. From the moment the gate drops, the 2012 KX450F is set to leave challengers in its dust.

The 2012 highlights begin with the Supercross-winning DNA of last year’s bike. The advanced design of the aluminum perimeter frame and dominating motor receive a host of refinements to create a more compact and mass-centralized chassis propelled by more usable power than ever. Headlining the technological charge, the KX450F features an all new Launch Control Mode, which is tuned to maximize traction out of the starting gate. This is accomplished without sacrificing any of the mid-range grunt or straight-line speed that made the KX450F famous.

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.

No other production motocrosser offers a higher degree of adjustability to the rider interface or engine character than the new 2012 KX450F. With a choice of four different handlebar positions, two footpeg positions, and virtually unlimited ignition mapping capabilities – thanks to its advanced Digital Fuel Injection (DFI®) system – the KX450F is uniquely able to adapt to changing track and surface conditions and meet the needs of a surprisingly wide range of riders.

The DFI system comes with pre-programmed ignition maps, but new for 2012, these maps are interchangeable without the use of a laptop computer – or other separate electronic devices. Maps can quickly and easily be changed between three settings – standard, hard (conditions) and soft (conditions) – by swapping the DFI wire coupler cap clipped to the side of the steering head. No additional accessories are needed to alternate between preprogrammed settings – simply install the coupler cap with your desired ignition mode and start winning. The ECU is also still fully re-programmable by using the accessory KX FI Calibration Kit, the same tool used by Kawasaki factory and privateer teams in AMA and FIM racing.

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 five-speed manual transmission handles the torque load with an ideal balance of precision and durability, thanks to an extra dog on the gears (up from 3 to 4) which improves shift feel. A new, shorter shift fork gives a smoother, more positive feel and reduces stress when changing gears, making shift action more efficient, while a new first gear is 2.8 mm thicker to enhance strength and durability. A new shift lever moves the pedal 3mm farther from the footpeg and offers greater durability. Finally, heavier clutch springs help channel the engine’s considerable torque when rocketing out of the gate.

Not only have the electronics, engine and gearbox been extensively upgraded, but a new frame and slimmer rider compartment also join the party for 2012. A total width reduction of 4mm across the main frame spars gives the 2012 KX450F the most slender mid-section ever. Chassis rigidity has been refined by altering the shape of the ribbing inside the new frame, creating more flex in the upper portion and stiffening the lower sections around the swingarm pivot. These changes helped increase rear wheel traction and also allowed additional room for the alternate footpeg mounting position.

In another industry-first innovation, the 2012 KX450F offers two footpeg positions to choose from. The alternate position places the footpegs five millimeters lower than stock, which not only allows for taller riders, but lowers the center of gravity and gives the rider a lower point of view, adding to both physical and psychological stability.

The tie rod arm of the Uni-Trak® rear suspension linkage is now slimmer, offering slightly less rigidity for added rear-wheel traction. Kawasaki will also offer an optional rear suspension tie rod, which can be used to reduce seat height. The optional unit is one millimeter shorter than stock, which translates to a six millimeter reduction in seat height – a subtle but effective change for “inseam challenged” riders.

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.

Up front, the Kayaba Air-Oil-Separate (AOS) fork keeps oil and air in separate chambers for remarkably stable damping performance during long motos. A revised lower triple clamp contributes to improved fork action. The new clamp can be recognized by its rear-opening design. The super-hard Diamond-Like Carbon (DLC) coating on the outer surface of the inner fork tubes and high-tech Kashima Coat treatment on the inner surface of the outer fork tubes significantly reduce drag compared to a standard fork assembly and help deliver supple, fade-free fork action.

Mass centralization and a lower center of gravity were additional targets for the 2012 KX450F, so a new fuel tank, upgraded bodywork and a shorter muffler help relocate weight toward the center of the motorcycle and make the new KX more nimble than ever.

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.

The 2011 KX450F is available in Kawasaki Lime Green, with black alumite-coated rims, blue anodized highlights and aggressive graphics.

Racers who ride their KX450F at designated events are eligible to receive support from Team Green™, Kawasaki’s amateur racing support program. Each year, Team Green provides regional support vehicles and highly trained technicians at more than 100 events throughout the United States, offering technical information and assistance to those who race Kawasaki products. Kawasaki also offers a comprehensive contingency program for amateur and professional riders who place well at designated events.

2012 Kawasaki KX™450F

Features and Benefits

At a glance…

All-new Launch Control Mode increases the chance of nailing the holeshotNew pre-programmed ignition maps, interchangeable trackside, no PC requiredUpgraded engine with more top-end thrust and a wider powerbandNew adjustable bar and footpeg positionsNew slimmer frame and minimalist bodyworkUpgraded transmission for easy, reliable shiftingNew pipe and silencer help centralize mass50mm AOS forks with DLC coated inner fork tubesBlack Alumite coated rims

Engine Overview

449cc liquid-cooled, DOHC, four-stroke singleWorks-based Bridged-box Bottom piston has revised rigidity for improved high-rpm powerRevised intake cam and all-new exhaust result in wider powerbandA forward lean angle of 3° puts the engine in the ideal position for maximum tractionHighly balanced crankshaft, on par with Villopoto’s factory racer, creates minimal vibrationMaintenance-free automatic cam chain adjusterLarge airbox flap helps prevent mud and water from entering

Bridged-box Bottom Piston

Thinner top ring and revised surface treatment of oil ring reduce frictionSame design as used on our factory racers; offers optimum performance at all rpmLighter and more durable than traditional piston designsShort piston skirt features low-friction coating to minimize mechanical lossesReinforced external ribs enhance strength and durability

Cylinder Head

Compact head is only 100mm tallIntake camshaft profile revised to increase intake for better low- and mid-range power36mm titanium intake and 31mm exhaust valves with aluminum spring retainers minimize reciprocating weight and cylinder height to help ensure reliable valve control at high rpmDouble valve springs allow a short cylinder head height and help ensure stable valve operationCamshafts, lobes and tappet surfaces feature a soft-nitride treatment for long wear and high-rpm reliability


Crankshaft with high inertial mass helps maximize rear wheel tractionWedge-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 enginesNet result is reduced engine vibration, smoother power delivery and increased performance, with a noticeably snappier response at low rpmCrankshaft 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/landingIt is not necessary to re-tune, or change any jets to suit climatic conditions like on a carbureted modelUltra-fine atomizing injector with 12 holes sprays particles with a droplet size of 60μ for smooth power delivery and engine response throughout the throttle range43mm throttle body uses a progressive throttle linkage to deliver airflow in much the same way as an FCR carburetorUsing two linked shafts, the throttle body opens more quickly after reaching the 3/8 open positionFast-idle knob on the throttle body allows riders to increase engine speed when starting a cold engineFuel injector set at 45°, the optimum angle for mid-range power

Launch Control Mode

Factory-style launch control system increases chance of getting a good start by maximizing traction on a slippery surfacePush-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 clutchLaunch Control can be activated in neutral, first or second gearShifting into third gear deactivates Launch Control Mode and returns the ignition to normal mappingSystem 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 necessaryNo battery needed; the engine can be started with only three rotations of the crankshaft using the electricity generated by a single kick of the starterThe system delivers electricity to FI system in sequence: first the ECU, then the fuel pump, and finally the injector for quick, easy startingThe 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 preferenceThe 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 voltage2012 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 smoothlyStrong 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 batteryEquipped with an automatic compression release (ACR) system for quick and easy starting. The dual-weight centrifugal decompression system is fitted to the exhaust camCompression 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 reductionFeatures 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 ridingNew 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 efficiencyChanged left side radiator upper pipe angle for new shroud designNew shroud shape features a slimmer profile and larger cooling outlet holeRadiator 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 controlHeavier clutch springs give a more positive feel to the riderExcellent oil drainage contributes to more direct feelFriction plates with substantial friction material contribute to a direct feelNew 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 racingRevised number of gear dogs (3 dogs/3 holes to 4 dogs/4 holes) improve shift feelThicker first gear offers greater durability for launching off the lineShorter shift fork (5.3mm to 4.4mm) reduces the shift force necessary to change gearsNew shift lever moves the pedal 3mm farther from the footpeg and offers greater durabilityNew polyurethane resin drive chain roller reduces weight


New tapered header pipe is shorter in length and features a smaller overall diameterTapered mid-piece is new for 2012 KX450FNew 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 designPowerful twin piston hydraulic front caliper squeezes 250mm rotorLightweight rigid-mounted front disc reduces unsprung weight by 80 gramsSingle 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 kneesIncreased 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 handlingTapered “D” shape swingarm provides ideal rigidity for excellent stability, and is lighter than a comparable box-section unitAlloy swingarm features a cast front section, tapered hydroformed spars and forged chain adjustersUni-Trak® rear suspension linkage altered for improved traction, utilizing a revised tie-rod unit which is less rigidSuspension arm is mounted below the swingarm to allow a longer rear suspension stroke and more precise tuningNew 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 performanceRevised lower triple clamp locates the clamp opening in the rear as opposed to the side for increased rigidity and improved fork actionKayaba 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 actionDiamond-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 corneringFriction-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 feelWrap-around fork tube guards offer effective protection for the sliders

Rear Shock

Rear suspension settings and linkage ratios derived from extensive rider testingKayaba rear shock features a large 50mm pistonRear shock features dual compression adjustability, allowing high-speed and low-speed damping to be tuned separatelyAlso features Kashima Coat treatment on the cylinder for reduced friction and smoother suspension actionEasy 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 comfortUpgrades bodywork features more flush seams for easier rider movementLower-capacity fuel tank is shorter and narrower, creating a straighter line from the seatBlack plastic covers, triple clamps, engine covers, and black alumite-coated rims – just like Kawasaki’s factory teamsBlue alumite finish on suspension adjusters and engine plugs match new graphics accentsWide 50mm footpegs can be adjusted to alternate position, 5mm lower than stockFrame is wider at the ankles to offer optimum grip, narrows below the seat to allow a slim riding positionSlim 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 weightClutch cable boot features a large quick adjuster, making it easy for riders to adjust play in the clutch cable on the flyRear caliper guard helps protect the caliper from damageRibless rear hub and butted spokes offer light weight and excellent durability

2012 Kawasaki KX450F Specs

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