2015 Kawasaki Jet Ski Ultra 310X Review

Brutal power with a hull that can keep up

Kawasaki remains king in terms of horsepower for 2015. As its name suggests, the Ultra 310X delivers 310 horses of it, enough to push the craft across the water at thrilling speeds and instantly put you in contention for any neighborhood grudge match.

The Ultra 310X, however, is much more than a speed machine. It’s matured into a well-rounded performer that now serves a variety of audiences. And much of its success starts not with its engine, but instead…

That Hull

Yes, truth be told, any review of the Ultra platform will inevitably turn not to the brute force under the saddle, but to the strengths of its hull design. So, let’s start below the bondline.

The Ultra 310X’s hull is perhaps the best in the industry at tackling rough water.

The Ultra hull is quite simply one of the best rough-water platforms on the market. It doesn’t get bounced around on the waves, pushed off its course, or mercilessly pound its driver. Instead, the boat’s trademark deep, 22.5-degree deadrise V slices through the chop with the precision of a Japanese hibachi chef. It’s this very reason the boat continues to be one of, if not the favorite ride of offshore race jockeys. Spray-reducing chines greatly diminish the inevitable spray brought on by such rides, and a comfortable saddle and grippy footwells make sure you’ll stay put in the saddle above. Yet for all its race-jock appeal, the craft’s confident, forgiving manner means it will serve not only the sporty audience it’s seemingly intended for, but also the novice rider as well. That’s a tough mix to pull off, and Kawasaki continues to do it better than most.

COMPARISON: Read our review of the 2015 Kawasaki Jet Ski Ultra 310R

Despite its rough-water prowess, the Ultra 310X is also an agile performer in calm conditions.

Calm-water enthusiasts, however, shouldn’t dismiss it as only a rough-water ride. That same hull is surprisingly agile in smooth water as well. Trace much of the reason to its shortened, fast-reacting steering nozzle and electric trim system. By lowering the bow, riders can put more of the hull into the water and find the Ultra can carve a sharp, aggressive corner. Enhance it further with a natural, intuitive inside lean. Get a rhythm going in left-to-right turns and you’ll feel like a slalom water skier, putting up a wall of spray with each successive carve.

Those Extras

And above the bondline, the Ultra 310X continues to shine. Often literally. Kawasaki’s fit and finish is exceptional, from paint to parts to hinges and latches. That gives the Ultra a solid, sturdy feel. Extras aren’t extravagant, but more to the point. The electronic throttle control makes possible the addition of cruise control and a no-wake mode. Cruise makes for more comfortable long-distance rides, locking in the speed and letting the driver just fully squeeze the throttle to avoid extended pressure on the trigger finger. Use it to also deliver a more consistent ride, and avoid those inevitable throttle surges, when pulling skiers and wakeboarders. No-wake likewise eases extended slow-speed cruising by keeping the craft moving forward at about 5 mph with no throttle input required. Tilt steering accommodates differing driver sizes, but also proves useful when riders wish to stand to absorb the ride in rough waters, as it allows you to tilt the angle upwards and limit the amount you’re forced to bend forward.

Tilt steering lets riders of virtually any size get comfortable.

COMPARISON: Read our review of the 2015 Sea-Doo RXT-X 260

Riders will likely appreciate the Ultra’s info display. It’s easily read in bright sunshine, and goes as far as to show fuel consumption, which can come in handy given the potency of the craft’s engine. Additional features worth noting include the dual magnetic-key engine activation system; use one for everyday use, the other to limit speeds. When removed, both disable the ignition to prevent someone from “borrowing” your ride. Storage and fuel capacity also deserve mention. The Ultra’s 56-gallon storage capacity is exceptional, and 20 gallons of fuel is, likewise, more than you’ll find elsewhere.

And Now…That Engine

Producing an industry-leading 310 horsepower, Kawasaki’s 1,498cc engine puts brutal power at your disposal.

It’s the final piece of the puzzle. The Ultra 310X performs so well hurtling across those ocean waves and powering through those aggressive turns in good part because of the powerplant below its seat, a 1,498cc inline four-cylinder equipped with an Eaton Twin Vortices consant-displacement supercharger and large, liquid-cooled intercooler. Various tweaks, including new cast pistons, a heat-resistant plastic intake manifold, and new fuel pump, contributed to upping the previous 300 horses to 310 in 2014. A new impeller design also promises improved acceleration.

COMPARISON: Read our review of the 2015 Yamaha FX Cruiser SVHO

Numbers? Expect a potent bottom end, with plenty of power to get the jump on your riding buddies or pull up heavier riders when towing. That power comes on with the Ultra’s trademark, deep-throated roar, just like it always has in the past. I continue to record top speeds of 67 mph in good conditions and with a light load. The magical 65 mph is certainly reachable in nearly any conditions.

Things aren’t all rosy. Respect that much power, especially when the off-throttle steering response occasionally kicks in. The latter can cause a surprising surge, such as when you come in a little too hot to the dock or approaching a group of friends. That powerful engine also has a taste for fuel, and lots of it at peak speed. Then again, so do most machines in this category.

Ultimately, however, enjoy that power, and that hull, and those extras. They combine to deliver one of the most sought-after points of a personal watercraft – fun factor – and they do it Ultra well.