Summer’s right around the corner and for those who enjoy getting wet Kawasaki’s got something exciting with its updated Ultra 310X Jet Ski (starting at $15,299—and $17,999 as tested in ‘LX’ trim). Available in standard, ‘SE’, ‘LX’, and ‘R’, variations, the 310 is Kawasaki’s flagship and adventure-ready three-person watercraft.
Kawasaki’s been carefully crafting Jet Skis for 40 years—longer than any other brand—and it shows in the assembly and design detail of its latest machine. As the nomenclature insinuates, the big news for the Ultra line is the 10 horsepower increase. To accomplish this, engineers modified the intake manifold for improved flow at lower engine speeds as well as installed a higher capacity fuel pump (however the 500cc flow rate of the four fuel-injectors remains unchanged) . The pitch of the three-blade impeller was also tweaked (with an effect similar to installing taller gearing on a motorcycle, for higher top speed) amounting to a smoother thrust at all engine speeds.
Other improvements focus on durability, with the installation of new pistons and added oil cooling jets for enhanced thermal control. The size water jackets were also increased and the oil pan has extra baffles to reduce oil slosh in motion. The oil return passages within the crankcase were also expanded. Besides those updates, the water-cooled and fuel-injected Inline Four engine continues to displace 1498cc and sports a giant intercooled supercharger that provides up to 17psi of boost netting up to 310 peak horsepower (measured at the crankshaft).
(Top) The Ultra 310 gets its muscle from a giant 1498cc Inline Four with an Eaton supercharger. Also note the updated shape of the passenger handle. (Center) The 310 continues to employ a giant storage compartment at the front of the ski. Only problem is it isn’t waterproof so you still need a dry bag for items you can’t get wet. (Bottom) The instrument display offers lots of information and is easy to see while riding. We wish you could navigate its functions through a handlebar-mounted switch.
Keeping in mind the borderline outrageous propulsion of the last year’s Ultra 300 the new 310 isn’t noticeably faster off idle. It is, however, more snappy—especially through the mid-range—say, when yanking on the throttle trigger from around 30 mph. Power delivery continues to be immediate but smooth. Still, considering how forceful the engine is, the 310 is not for beginners. Appropriately, Kawasaki includes a ‘SLO’ yellow ignition key that moderates acceleration force and limits top speed for first-timers, or those that simply don’t want to experience the force a bullet is subjected to when it’s fired from a gun. Contrarily, for adrenaline fiends, the standard green key (previously colored orange) is all you’ll need. With it we saw an indicated and electronically limited top speed of 67 mph.
The Ultra’s engine is fed from a 20.6-gallon fuel tank that’s accessed beneath the front hood. Kawasaki recommends running higher octane, premium unleaded fuel, though the engine is equipped with an anti-knock sensor to suppress engine ping if you accidently run a lower grade fuel. Under full throttle the Kawasaki’s Inline Four is thirsty and can easily drain the gas tank in a couple hours. However, if you show trigger finger restraint it’s possible to get a full day’s worth of riding on a single tank. Range can further be extended by depressing a blue button, mounted on the left handlebar enabling ‘ECO’ mode. And when the tank does get low a warning light comes on the dash along with an audible beep that can be manually disabled by pressing one of the dash buttons.
Another nice touch is the fast idle/five mph ‘no-wake zone’ mode that comes in handy when trying to reach open water. The 310 is also equipped with cruise control that works well if you wish to maintain a steady speed while towing a tube or skier. Problem is it isn’t hands free—requiring the rider to maintain pressure on the throttle, which negates its usefulness.
The updated instrument panel looks clean and is legible at speed. In addition to speedometer, tachometer, supercharger boost, and fuel level, the rider can monitor riding time (hours and miles), air and water temperature. There’s also fuel consumption info along with a clock. Each feature can be accessed by pressing a button below the display. But it would be better if Kawasaki could integrate menu control into the handlebar.
Physically, the Ultra is a substantial craft weighing 1048 pounds and measuring over 11 feet from bow to stern. Yet on the water it’s surprisingly agile and not overly cumbersome to maneuver. Experienced riders might be unnerved by the ghost in the machine-like response of the Smart Steering electronics, which automatically elevates engine rpm to maintain a turn if you let off the throttle and simultaneously crank the handlebar either way. Nevertheless, it’s a valuable feature for newbies who aren’t fully accustomed to the ‘stay on the gas to steer’ dynamics of a personal watercraft. Either way you get used to it after a short ride. We’re also fond of its lever-operated reverse feature, which comes in handy when docking, or any other slow speed, close quarter maneuvers.
(Above) With the addition of JetSound the Kawasaki Ultra 310 is that much more enjoyable to operate on warm days. (Center) The design of the Ultra’s eight-vane intake and jet pump keep the pump filled with water, maximizing propulsion when the ski jumps out of the water. (Bottom) The Ultra 310 LX gets a main seat with extra support for added comfort on the water.
The Kawasaki’s hull design helps it charge through rough water with a high degree of stability. It maintains trajectory well yet remains responsive to subtle movements of the handlebar. The shape of the eight-vane intake grate keeps the jet pump loaded with water, reducing cavitation and maximizing propulsion even when the hull momentarily jumps out of the water at speed. Furthermore the angle of the pump can be adjusted eight degrees up or down via the handlebar trip button. This allows the rider to tailor the ski’s handling based on water conditions and or carrying load. An indicator within the LCD display illustrates the position.
In flat water it carves turns voraciously with a similar turning effect as a Ninja sportbike with high grip tires on asphalt. It’s an exhilarating, and relatively safe experience, since if you fall you’re crashing into water, not a guard rail, tree, or any other object that can cause injury on the road.
The cockpit of the Ultra is spacious and capable of accommodating three adults. There’s an abundance of room behind the handlebar—a big plus for larger than average pilots. We also like the ability to adjust the height of the handlebar (up or down, in five positions) based on preference. We prefer the highest setting as it makes the 310 feel more like a dirt bike. It’s important to note that the ‘R’ model deletes the adjustable bar for a fixed, dirt bike-style one fabricated from steel with matching top clamp. Thankfully if you don’t like the stock, low bend, the set-up can be swapped for another aftermarket bar with a basic set of hand tools. The hand grips offer adequate grip but can irritate the rider’s hands so it’s a good idea to wear a set of gloves when riding (see Slippery Wetsuits sidebar).
Storage is also plentiful with a giant compartment underneath the front hood, capable of swallowing 54-gallons of gear. A nifty removable tray keeps items from bouncing around on the water. Two additional partitions are located beneath the handlebar and underneath the rear seat but the latter are too small to be useful for anything else but a small pair of sandals. Another strike is that none of the compartments are waterproof so you’re going to need to bring along a dry bag and/or box for delicate electronics like iPhones, etc.
The floor area is covered in Hydro-Turf matting which provides fantastic grip and a degree of added impact absorption when standing and charging across choppy water. The shape of the rearview mirrors was also tweaked for enhanced view of what’s behind and the shape of the rear passenger handle was also updated for improved comfort. The ‘LX’ also uses a more seat with extra rider and passenger support and a special cover that dissipates heat better to prevent burns after remounting the ski when it’s been under the hot sun all-day. The Ultra continues to have a wide rear deck platform and a nifty step ladder that makes it easier to climb aboard the craft from the water.
Without question, the greatest new feature on the Ultra LX is the fitment of a fully integrated stereo. Coined as JetSound, the system is comprised of a pair of rear-facing 30-watt marine speakers built into the ski’s forward cabin. The speakers are powered by two 20-watt amps. An auxiliary headphone-style input is located inside the center storage box along with an USB-compatible memory stick. Both can be accessed via independent waterproof cases and controlled remotely
(Above) The JetSound stereo is controlled via this circular control panel. The buttons are tiny and hard to manipulate while riding with gloves. The LX is also compatible with many hand-held GPS’ including this unit from Garmin. (Center) The JetSound system is comprised of twin 30-watt marine speakers. They delivery crisp sound through the volume range. (Bottom) The Ultra 310LX’s JetSound system can be fed music through an USB-style memory stick (up to 4gb) or an auxiliary headphone-style input that is compatible with most smartphones and music playing devices.
through a series of buttons on the handlebar. A built-in receptacle for a handheld GPS is located next to the audio controls.
The sound system functions brilliantly, delivering crisp sound at all volume levels. It also gets loud with the maximum setting so overpowering that we had to turn the volume down a couple of notches when stopped or at idle. As speed increases the music is drowned out with wind and the whistle of the supercharger, but it’s a great feature at slow speeds and we applaud Kawasaki’s effort as it makes getting on the water that much more entertaining. However, there are two downsides: First, the buttons on the handlebar are so tiny that it’s hard to change tracks or manipulate the volume especially with gloves. Another squawk is that the system automatically powers off after three minutes once the engine is killed, which limits usefulness when taking a break at a beach or relaxing on a sandbar. When the ride is over and you pull the ski out of the water there are two drain plugs and flush receptacles (one for the engine/jet pump, and one for the supercharger) making clean-up a snap.
Kawasaki’s Ultra line of Jet Skis was already the gold standard in the PWC world and it would have been easy for the Green Team to simply carry over what it had for ’14. Instead, through careful refinements it has managed to enhance performance while also boosting entertainment value, practicality and usefulness. While it certainly can’t be termed cheap (base price crept up by $200) if you’re seeking the most premium and versatile jet-powered watercraft the Kawasaki 310 should be atop of your list.
- Borderline insane amount of power and thrust
- Agile and stable in rough water
- JetSound system makes riding that much better
- Supercharged engine can be very thirsty
- No waterproof storage
- Navigating the display functions requires the rider to stop
Engine: Water-cooled, supercharged and intercooled, four-stroke, DOHC 1498cc Inline Four, 16-valves
Bore and Stroke: 83.0 x 69.2mm
Compression Ratio: 8.2:1
Induction System: Eaton Twin Vortices Series roots-type superchrager with air-to-water intercooler
Maximum Boost: 17.0 psi
Maximum Horsepower: 310 (at crankshaft)
Fuel Delivery: Fuel-injection
Propulsion System: 160mm jet pump, axial-flow, single stage
Impeller: Three-blade, oval-edge stainless steel
Thrust: 1890 lbs.
Seating Capacity: Three-person
Load Capacity: 496 lbs.
Engine Oil Capacity: 6.0 quarts
Storage Capacity: 56 gallon
Curb Weight: 1074 lbs.
Length: 132.7 in.
Width: 47.0 in.
Height: 45.3 in.
Fuel Capacity: 20.6 gallon
Colors: Ebony / Candy Lime Green; Ebony / Sunbeam Red
Warranty: 12 months