IF IT’S NOT A KAWASAKI, IT’S NOT A JET SKI.
Starting with a high-performance engine from the legendary Kawasaki Ninja® motorcycle line, the JET SKI® STX®-15F delivers a flat torque curve for a smooth spread of power across the entire rpm range. A long-stroke design was needed to achieve this broad torque curve, so while the engine’s bore is the same as the smaller JET SKI STX-12F, its stroke is 13.8 mm longer, increasing displacement to 1,498 cc. Dual overhead cams, four valves per cylinder, fuel injection and electronic engine control--to harmonize the fuel and ignition systems--provide maximum performance and reliability, and the fuel injection system utilizes four injectors and a large 60 mm throttle body to deliver a quick response.
High-performance doesn’t have to mean high emissions; the STX-15F has earned a Three-Star Ultra-Low Emissions rating, meeting the Environmental Protection Agency’s (EPA) strictest standards, as well as the California Air Resources Board (CARB) standards for 2008. It’s also as civilized as it is clean-running: the four-stroke engine is rubber-mounted in the hull and includes a water-jacketed, performance-tuned exhaust system, dual mufflers and a large-capacity airbox.
For propulsion, the STX-15F utilizes a direct drive axial-flow jet pump connected to an oval-edge, stainless steel, three-blade impeller and an 82 mm jet pump nozzle for powerful acceleration. That doesn’t meant, peaky, unmanageable performance: the STX-15F engine produces its peak power at a relatively low rpm while matching the impeller’s peak efficiency rpm. This eliminates the need for a complex gear reduction unit, resulting in improved durability, increased fuel economy as well as reduced vibration and noise.
Kawasaki Smart Steering® (KSS®) equips every STX-15F. KSS features an on-board microprocessor that is electronically linked to a steering sensor. If the handlebar is fully turned in either direction and the engine rpm drops from a designated rpm—as when the throttle is released at speed—the microprocessor activates the KSS, which raises engine rpm to provide enough thrust to initiate the desired turn.
The STX-15F features Kawasaki’s innovative electronic Smart Learning Operation (SLO). Accessible directly on the instrument panel, SLO can be programmed to place a limit on maximum engine speed so novice riders can experience riding at a reduced speed while they master proper riding techniques. Aggressive turning and high-speed stability are key performance attributes of the STX-15F. Injection-molded sponsons designed specifically for the STX-15F feature a special “lip” for increased cornering grip and high-speed stability. The hull also features a molded-in Kawasaki Splash Deflector (KSD) to help minimize spray on the rider.
With its muscular, aggressive look, the STX-15F is lighter and more compact than the competition, yet Kawasaki engineers have created a spacious riding position that makes aggressive performance riding easier and suits a wider range of riders. The hatch cover is styled from sleek ABS plastic, adding to the fresh, high-quality styling of the STX-15F, and a hydraulic damper holds the hatch cover open, allowing easy access until the rider closes it. The mirrors are also made of ABS plastic and mount directly to the deck, which adds to the sleek lines. The open rear deck of the STX-15F features abundant space for getting into water skis or on a wakeboard, and re-boarding in deep water is simplified with an automatically retracting boarding step located on the rear of the hull. The rear deck can also accommodate items needed for a day on the water, like a cooler. There’s also a water-resistant storage space, an easily accessible glove box and additional room for gear located under the seat. Other features include a LCD instrument panel so the rider can monitor the fuel level, speed, engine rpm, trip distance and time. Fuel capacity is a generous 16.4-gallons, for extended rides. Warning lamps alert the rider to low fuel level or high engine temperature, and a magnetic keyed ignition switch helps deter unauthorized operation.