FIRST LOOK AT THE TWENTY-TEN KWACKERS: The 2010 Kawasaki’s Are Here! The New Models: One EFI, Two Carbed; One Two-Stroke; It’s Deja Vu All Over Again

Fuel-injected perfection for demanding riders

    The 2010 Kawasaki KX450F provides an ideal platform for riders looking to win races. Its precise aluminum frame, premium suspension components and expert-tuned settings are designed to deliver superb high-speed stability, enabling racers to capitalize on its amazing engine performance. Holeshot acceleration is delivered by a strong powerband and optimized chassis geometry specifically engineered to maximize rear wheel traction. Monster Energy Kawasaki rider Ryan Villopoto used his new KX450F to win several AMA Supercross and Motocross races, during his first year on a 450.  

    The KX450F features a number of engine refinements, including the first mass-production use of a high-performance bridged-box bottom piston that offers more power in the high and over-rev rpm ranges. Revised cam timing and ECU settings provide better mid-high rpm performance, while reinforcements to the cylinder sleeve and right side crankcase increase durability.

    The race-ready engine is compact and light, with a short 100mm cylinder head and a 12.5:1 compression ratio. A wedge-shaped crank web offsets 60% of the crankshaft’s reciprocating weight, producing an effective “counterweight” effect. This is on par with Kawasaki’s factory racers and helps reduce engine vibration, smooth power delivery and enhance low-rpm throttle response.  A new 40mm shorter stainless steel exhaust pipe connects to a large-volume silencer which uses long-fiber packing material to maximize service intervals. A new rubber damping collar in the rear silencer mount provides a boost to long-term durability.

Factory-style components and tuning for every racer

    Kawasaki’s KX250F motocrosser had a victorious year, winning on the track and topping its class in numerous enthusiast magazine shootouts. The successful mix of the highly rigid aluminum frame and top-shelf suspension components deliver superb high-speed stability, while its chassis geometry and high-revving engine offer excellent rear wheel traction and holeshot-winning performance. Christophe Pourcel used his new Monster Energy/ Pro Circuit / Kawasaki KX250F to win the AMA East Supercross Lites Championship and then continued his winning ways into the outdoor season. But in the volatile world of racing, it’s a constant challenge to stay on top.

    To ensure it continues its podium-topping tradition, Kawasaki fine-tuned the light handling KX250F for 2010. The engineers capitalized on its solid foundation, with refinements focused on increasing performance and longevity. The result of their labors will help the KX250F add to its ever-growing trophy collection.

Borrowing from the racing world, the KX250F gets a new piston with a bridged-box bottom ? making its first appearance in a mass-production machine. The new piston is lighter and stronger. It also has a revised profile with a shorter skirt and shorter piston pin, which reduces reciprocating weight. It also features a revised crown that improves combustion. The cylinder height was raised accordingly to maintain the 13.2:1 compression ratio. Low-rpm performance was bumped up via a new longer head pipe and shorter mid-section on the new, more durable stainless steel exhaust pipe.

    The 249cc, liquid-cooled, four-stroke engine received a number of other refinements for 2010, such as electrofusion treatment on the cylinder bore, revised oil pump rotors and a wider big-end bearing to increase engine life.

Tomorrow’s champions start here

    For the growing, young rider ready to step it up to the next level or slightly older beginners looking to start racing, the Kawasaki KX85 is a youth racer’s dream. Powered by a liquid-cooled, two-stroke, single-cylinder 84cc engine that generates race-winning power, the KX85 is packed with high-tech features such as an electrofusion-coated cylinder with a narrow squish band and large-volume combustion chamber to boost top-end power.
    Its 28mm Keihin carburetor features a crescent-shaped slide, which permits positioning the needle closer to the intake ports, optimum fuel atomization and smoother fuel delivery throughout the powerband. Further enhancing the KX85’s tractable power delivery are the Kawasaki Integrated Power-valve System (KIPS?) and tuned exhaust pipe that provides better drive out of the corners and a linear power delivery for young riders of varying skill levels.
    The KX85’s six-speed transmission delivers smooth and positive shifting along with enhanced durability thanks to hard chrome-finished shift fork ends, a thick base on the clutch basket housing and an additional bushing on the input shaft.
    A high-tensile steel perimeter frame, with a specially designed gas tank that sits inside the frame, keeps the fuel load and center of gravity low for improved handling ? yet another beneficial feature borrowed from KX85’s larger siblings.

    To view all of the photos that Kawasaki has supplied for the 2010 KX450F, KX250F and KX85, please visit our photo gallery or simply click here.