Especificações técnicas
Kawasaki Ultra 250X
250 HP turbo - 1500 cilindradas
Tipo de motor - A 4
tempos, Quatro Cilindros em Linha
Cilindrada - 1.498 cm³
Diâmetro x curso - 83 x 69,2 mm
Razão de compressão - 7.8:1
Potência máxima - 184 kW
{250 PS} / 7.750 rpm
Binário máximo - 237 N.m
{24,2 kgf.m} / 6.500 rpm
Sistema de refrigeração
- Água aspirada
Sistema de injecção - Injecção
de combustível: ø 60 mm x 1
Ignição - Digital
Arranque - Eléctrico
Sistema de propulsão - Bomba de
jacto, fluxo axial, fase simples
Thrust - 6.780 N {692 kgf}
Lotação - 3 pessoas
Dimensões CxLxA - 3.370 x 1.195
x 1.150 mm
Capacidade do depósito de combustível
- 78 litros
Peso a seco - 410 kg

2008 KAWASAKI JET SKI® ULTRA®
250X
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.
Características
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