Introduction
The 250 horsepower pinnacle of PWC performance
Kawasaki extended its high-performance domination into the realm
of personal watercraft with the 250 horsepower JET SKI® Ultra®
250X. The quickest and most powerful production PWC in history,
Kawasaki's supercharged Ultra 250X tears across the water at
an electrifying pace that will invigorate even the most jaded
of speed enthusiasts. Once up to speed, its precise handling
and superb stability are equally impressive, thanks to a hull
specifically designed to capitalize on the engine's awesome performance.
The JET SKI Ultra 250X's engine, jet drive and hull incorporate
racing technology refined through Kawasaki's multiple IJSBA championships.
This knowledge application allows it to deliver the awesome acceleration
of a drag racer, and help ensure excellent hook-up even
in rough water.
With a 1,498cc engine derived from Kawasaki's capable JET SKI
STX®-15F watercraft as the foundation, the Ultra 250X produces
power comparable to a normally aspirated high-performance three-liter
engine. It accomplishes this amazing feat via the addition of
a Roots-type supercharger. Unlike centrifugal superchargers or
turbochargers, the Ultra 250X's high-volume direct-drive supercharger
delivers boost virtually instantly at any engine speed from idle
to redline. This produces a linear, smooth torque curve that
is ideal for a personal watercraft that needs to accelerate hard
all the way from a standstill to its breath-taking top-end speed.
Heat build-up from compressing the intake air is a common drawback
of forced-induction. The Ultra 250X uses of a large-capacity
intercooler to overcome this handicap. With the 250X's supercharger
compressing the air to a maximum boost pressure of 11.4psi, the
intake charge can reach extremely-high temperatures potentially
limiting the engine's power output. However, the 250X's large-capacity
intercooler brings the pressurized air down to ambient temperature
or even less ideal for producing maximum power.
A huge 155mm jet pump featuring the largest PWC impeller and
nozzle Kawasaki has ever produced transfers the big power from
supercharged 1,498cc engine into the JET SKI Ultra 250X's blazing
acceleration. Developed based on lessons learned from Kawasaki's
race machines, this pump was designed to deliver predictable
thrust and good "traction," even in rough water.
A significant factor in this extra "traction" are the
pump's eight guide vanes that smooth the flow of water from the
impeller for efficient and powerful propulsion. The pump also
incorporates a groove from the center to the rear of the ride
plate which makes it easier to hold a stable heading for straight
line riding. Complimenting the 155mm jet pump is an equally large,
sophisticated three-blade impeller that delivers high performance
with smooth and quiet operation.
In addition to more power and acceleration than any other production
watercraft on the planet, the Ultra 250X also boasts a race-developed
hull. Its hull design is just as comfortable in rough conditions
as in calm. Even at high speeds, rough water can do little to
deter the Ultra 250X. This combination of unearthly power mated
with the latest hull technology permits Kawasaki's flagship to
literally cleave through waves that would send lesser machines
ricocheting to a safe harbor.
Thanks to a specifically engineered hull, the Ultra 250X has
the precise handling and superb stability to match its acceleration
and top-speed capabilities. A fiberglass reinforced plastic (FRP)
hull, it is loaded with DNA from Kawasaki's IJSBA championship
winning machines. This includes carefully designed sponsons and
chins for enhanced straight-line stability and precise cornering,
combined with a 22.5° deep-V hull that leans into corners
like a motorcycle. This provides a smoother ride in rough water,
helps passengers keep the rider in control during peak cornering
g-forces.
The Ultra 250X features a five-step adjustable handlebar position
that allows either stand-up or sit-down riding for a wide range
of riders to enjoy superior comfort and versatility. As Kawasaki's
flagship watercraft, the 250X includes thoughtful standard features
like an enormous 53-gallon of storage space including a detachable
front storage compartment and a 20.6-gallon fuel tank for substantial
cruising range.
From horsepower to handling and everything in between, once the
spray settles after the first ride, one thing will be certain.
This powerful "ultra" JET SKI model delivers a level
of performance and excitement that is unmatched by any other
watercraft.
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Features
Engine
- Most powerful production PWC engine in the world
- Supercharged and intercooled, 1,498cc, liquid-cooled in-line
four-cylinder engine
- Compression ratio is 7.8:1 to minimize detonation at high-boost
pressures
- Inconel exhaust valves are fitted for superior heat resistance
and enhanced reliability
- 33.4mm intake and 28.3mm exhaust valves
- Precise power adjustments are easy with a throttle lever that
is designed to prevent finger fatigue on longer rides
Roots Type Supercharger
- Force-feeds the engine two liters of air with every revolution,
providing a stable supply of high-pressure intake air at all
rpm
- Produces large amounts of boost even at low rpm, for instant
and powerful acceleration right off of idle
- Provides a very flat and meaty torque curve with step-free
power across the entire rev range without any of the lag associated
with turbochargers
- Produces more low RPM boost than competitive or aftermarket
systems with a maximum of 11.4psi of boost pressure
- Two different air bypass valves are used to prevent over boosting
at low and medium rpm
- The smaller air bypass valve releases low amounts of excess
pressure build-up, for precise boost management
- The larger air bypass valve is used when excessive boost pressure
is accumulated, to maintain an even intake pressure even when
giving full-throttle from idle
Air-to-Water Intercooler
- Efficiently cools the high-pressure intake air
- Cooler air results in higher combustion efficiency and high
engine output
- Liquid-cooling allows the intercooler to maintain consistent
thermal performance
Fuel Injection
- High-flow fuel injectors with four orifices are fitted to complement
the increased power output and improve combustion efficiency
- Single throttle body features a large 60mm bore diameter
Exhaust
- 4-into-2-into-1 powerboat-style exhaust system, which routes
the exhaust pipe upwards.
- Allows the smoothest path for exhaust gases, maximizing exhaust
efficiency
Jet Pump
- Efficiently converts the Ultra 250X's massive horsepower into
thrust using a large-diameter 155mm jet pump
- Developed based on feedback from Kawasaki's race machines,
this pump was specially designed to deliver stable output and
good "bite," even when riding on rough water
- Reverse lever has been moved from the right side to the left
side for easier operation
Impeller
- The large, sophisticated three-blade impeller delivers
both improved thrust in the higher speed ranges and high performance
and quiet operation
Guide Vanes
- An eight-vane intake guide is used to smooth and regulate the
flow of water from the impeller for efficient and powerful propulsion
Ride Plate
- Features a groove from the center to the rear of the ride plate,
to enhance straight-line stability
Hull
- Feedback from Kawasaki's IJSBA championship winning racing
machines integrated into design
- Specially designed to cope with the engine's horsepower
- Offers a combination of high stability and responsive handling
in both calm and rough-water conditions
- Delivers the neutral handling and turning characteristics that
made Kawasaki JET SKI watercraft famous
- The lower hull is specially designed to distribute the engine
and power delivery loads over a wide area
- Although it has a similar V-shape to the JET SKI STX-15F, the
Ultra 250X's hull enables a high bank angle, for motorcycle-like
turning performance. This reduces the side G-loads imposed on
riders during turns
- The 22.5° V-angle at the bottom of the hull helps prevent
spinouts during sharp turns and to provide a smoother ride in
rough water
- Bottom of the hull slants upwards steeply from the center section
to the bow, so the Ultra 250X can penetrate swells and waves
with less shock; delivering extreme stability at low speeds and
pushing through waves rather than bouncing over them at high
speeds
- Battery located inside the front storage area near the center
of the machine, avoiding concentrating heavy components at the
rear and freeing up space inside the engine bay
- Integrated sponsons extend from the hull, providing stable
wallow-free straight-line performance and contributing significantly
to the 250X's excellent high speed maneuverability while helping
to retain the narrow hull design
Quattro KSD
- The Ultra 250X's Kawasaki Splash Deflector uses three bottom
mounted ridges and an additional deflector mounted at the top
to deflect water splashing forward from under the hull
- Whether turning or blasting straight ahead, at high speeds
or low, the Quattro KSD minimize spray, allowing greater rider
concentration
Kawasaki Smart Steering®/SLO-Mode
- Kawasaki Smart Steering® (KSS®) monitors steering input
and engine speed and, when certain conditions are met, raises
rpm to initiate a desired turn, helping new riders better enjoy
the performance of this remarkable machine
- Smart Learning Operation (SLO) allows newer riders to become
familiar with the handling and response of this JET SKI watercraft
at a more relaxed pace before unleashing the full performance
of the Ultra LX
- Two separate keys, one for SLO-mode and one for full-power
operation help prevent confusion over which setting is in use
Comfort and Convenience
- Five-way adjustable handlebars allow operation while standing
or sitting and suit a wide range of riders
- Relatively narrow seat is comfortable whether riding stand-up,
seated or with passengers
- Ergonomic deck design gives plenty of legroom
- A long rear boarding step makes it easy to climb onboard, and
the step retracts inside the bumper to prevent damage
- A quick and easy under hood hose connection allows an easy
method to flush sea water out of the engine
- Mirrors are mounted to the upper deck to facilitate opening
of the hatch cover
Capacious Storage
- The large-capacity, fully sealed 53-gallon storage area with
a detachable storage tray has plenty of room for recreational
equipment
- Mounted on the center console is a detachable drink holder
with space for two drink bottles
- Ideal for small items, a compact storage area is integrated
with the under-seat rear grip
Big Fuel Capacity
- 20.6 gallon fuel tank has more fuel capacity than any machine
in its class
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Technical Specifications
Engine: Supercharged and intercooled,
four-stroke, DOHC, four valve per cylinder, inline four-cylinder
Displacement: 1,498cc
Bore x stroke: 83.0 x 69.2mm
Compression ratio: 7.8:1
Induction system Roots-type supercharger with air-to-water intercooler
Maximum boost: 11.4 psi
Maximum horsepower 250hp @ 7,750 rpm
Cooling system: Inducted water
Fuel system: Digital fuel injection
Ignition: TCBI with digital advance
Starting: Electric
Lubrication: Semi-dry sump system
Coupling: Direct drive from engine
Propulsion system: 155mm jet pump, axial-flow, single stage
Impeller: Three-blade, oval-edge stainless steel
Thrust: 1,524 lbs
Seating capacity: Three-person
Load capacity: 496 lbs
Fuel capacity: 20.6 gal
Oil Capacity: 5.3 qt.
Storage capacity: 53 gal
Dry weight: 917 lbs
Overall length: 132.7 in
Overall width: 47 in
Overall height: 45.3 in
Colors: Sunbeam Red / Sunbeam Red
Valiant Blue / Valiant Blue
Jet White / Lime Green
* Price and specifications subject to change
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