When you’re out on the open seas, it’s important to carry as much power in your watercraft as you can get. But what’s even better than top-class power? Having equally impressive handling characteristics.

That’s what you get with the Kawasaki Ultra 300X. The 2012 Ultra 300X boasts incredible performance and thrust with a design that ensures typical Kawasaki reliability.

At the heart of the Ultra 300X is a monstrous 1,498cc inline-four DOHC engine that produces around 300 horsepower. Built in to assist the engine is a high-tech Eaton Twin Vortices Series (TVS) roots supercharger and Kawasaki’s Electronic Throttle Valve System, both of which help channel Ultra 300X’s tremendous power exactly where and how a rider wants it.

More than just the impressive performance characteristics, the Ultra 300X also boasts an array of futuristic electronics, including a highly advanced fuel injection system controlled by a high-tech Electronic Control Unit (ECU). This set-up not only commands the injectors and throttle bodies to route a precise amount of air and fuel mixture into the combustion chambers with help from the Electronic Throttle Valve (ETV) system, but it also allows a host of other technologies that can be used for your riding pleasure.

These include a range of varied riding “modes” such as Fuel Economy Assistance mode, a one-touch 5 mph mode, and the Smart Learning Operation (SLO) mode. The setup also includes a digital dash display called the Economical Riding Indicator that provides a clear guide to the rider when riding conditions are most efficient. The Ultra 300X also has an Electronic Trim Control (ETC) system, which controls the nozzle angle of the 160mm jet pump to adjust hull attitude to suit water surface conditions and riding style.

Find out more about the Kawasaki Ultra 300X after the jump.

  • 2012 Kawasaki Jet Ski Ultra 300X
  • Year:
  • Engine:
    inline-four DOHC engine
  • Horsepower @ RPM:
  • Displacement:
    1498 L


2012 Kawasaki Jet Ski Ultra 300X Drivetrain
- image 430095
  • Supercharged and intercooled 1,498cc, liquid-cooled inline four-cylinder engine
  • Cast pistons with machine finishing for excellent durability
  • Hardened nickel valves offer superior heat resistance and reliability
  • 33.4mm intake and 28.3mm exhaust valves
  • Two-layer oil cooler offers efficient cooling
  • Large cam chain handles enhance engine power
  • Reinforced crankcase adds to engine’s durability and reliability
  • Heat-resistant plastic intake manifold for weight savings
  • Optimum cylinder wall temperature is maintained by a check valve between the cylinder jacket and water muffler that shuts water flow off above 2,000 rpm, keeping the cooling water inside the cylinder jacket
  • Precise power adjustments are easy with a throttle lever designed to prevent finger fatigue on longer rides


2012 Kawasaki Jet Ski Ultra 300X High Resolution Exterior
- image 430100
  • Four-lobe design offers significant performance increase over standard roots-type unit
  • System force-feeds the engine two liters of air with every revolution, providing a stable supply of high-pressure intake air at all rpm
  • Delivers compressed air continuously, not in waves, for smoother power delivery
  • 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 17 psi of boost pressure
  • Two different air bypass valves are used to prevent over boosting at low and medium rpm

Key Features

2012 Kawasaki Jet Ski Ultra 300X High Resolution Exterior
- image 430101
  • Class-shattering 300 horsepower for outstanding performance
  • Strong, light, deep-V hull offers both stability and great cornering performance
  • Massive, industry-leading storage capacity lets you bring your gear with you
  • Largest fuel tank in class keeps the fun going longer
  • Five-position adjustable handlebar accommodates a variety of riders
  • Separate keys for full power operation and Smart Learning Operation


2012 Kawasaki Jet Ski Ultra 300X High Resolution Exterior
- image 430093
Engine Supercharged and intercooled, four-stroke, DOHC, four valves per cylinder, inline four-cylinder
Displacement 1,498 cc
Bore x Stroke 83 x 69.2 mm
Compression Ratio 8.4:1
Induction Eaton Twin Vortices Series roots-type supercharger with air-to-water intercooler
Maximum boost 17.0 psi
Maximum horsepower 300hp* * Horsepower measured in PS at the crankshaft under controlled conditions. Actual performance may vary.
Cooling system Inducted water
Fuel System Digital Fuel Injection
Ignition TCBI with Digital Advance
Starting System Electric
Lubrication Semi-Dry Sump system
Coupling Direct drive from engine
Propulsion system 160mm jet pump, axial-flow, single stage
Impeller Three-blade, oval-edge stainless steel
Thrust 1,769 lbs.
Overall Length 132.7 in.
Overall Width 47.0 in.
Overall Height 45.3 in.
Curb Weight 1040.8 lb.** Includes all necessary materials and fluids to operate correctly, full tank of fuel (more than 90% of capacity) and tool kit (if supplied)
Load Capacity TBD
Storage Capacity 60 gal.
Fuel Capacity 20.6 gal.
Oil Capacity 5.3 qt.
Color Choices TBD


MotorCycle-USA----"The biggest news however is the redesigned induction system highlighted by Eaton’s latest and greatest Twin Vortices Series (TVS) supercharger. This is the same supercharger that’s used in the 638 horsepower Corvette ZR1 and 556 horsepower Cadillac CTS-V sports cars. It delivers 6.3 psi more boost than before (17.3 max) which nets a total of 300 horsepower at just 7750 rpm (measured at the crankshaft). That’s over 200 horsepower per liter—a figure almost unheard of in the motorsports industry. A 20.6 gallon capacity fuel tank feeds the engine."

Kirby Garlitos
Automotive Aftermarket Expert - kirby@topspeed.com
Kirby’s first exposure into the world of automobiles happened when he caught Knight Rider on television as a five-year old boy. David Hasselhoff didn’t leave much of an impression on him (that happened later on in Baywatch), but KITT certainly did. To this day, Kirby remains convinced that he will one day own a car with the same ‘spirit’ as the original KITT (not the 2008 monstrosity). He doesn't know when that will be, but until then, he’s committed to expressing his love for KITT, and all cars for that matter, here at TopSpeed.  Read More
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  (399) posted on 01.9.2012

This one is really cool! I love the color green rather than the blue one. And the specs is quite outstanding with a 300 HP. This Jet Ski will surely hit the water fast!

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