2016 Sea-Doo RXP-X 300 Review

300-horsepower craft delivers in spades

By now you’ve likely heard the numbers. A 15% increase in power over the previous flagship engine. A supercharger that provides 30% more boost. A total of 300 horsepower. Sea-Doo’s new engine is one bad…well, you know.

Adding that power to a craft that is arguably the most aggressive handling model on the market promises big things. Does the RXP-X 300 deliver?

Like you really had to ask.

More Power

Many performance enthusiasts saw nothing of the preceding sentences except this – 300 hp – so let’s get right to the single biggest change to this craft for 2016; its new 1,630cc engine.

Yes, the 2016 RXP-X 300 delivers!

Based on the previous 1503 Rotax, the new three-cylinder 1630 ACE 300 features the identical 100mm bore, but introduces a longer stroke (69.2 mm vs. the former’s 63.4mm) to gain 9% in displacement. Within, cylinders forego conventional steel sleeves in favor of a plasma coating. The choice drops weight slightly, but more importantly provides a better heat transfer from the piston to the cylinder. Pistons themselves are beefier, but lighter by 20 grams and designed with longer, coated skirts. Connecting rods have also been lightened as well as shortened to accommodate the longer stroke.

Other improvements include a new coil-on-plug ignition system with nearly twice the discharge, single overhead cam cylinder head with improved combustion chamber shapes, and larger injectors.

While most of these improvements won’t be noticed with an exterior glance, changes to the cooling system, supercharger and intercooler are far more obvious. Cooling improvements include a larger heat sink, as well as an additional cooling circuit. And then there’s the much larger, more robust intercooler. Made from long-life alloys and featuring sacrificial anodes in both the intercooler itself and the water-passage tubes, Sea-Doo claims it’s 2.2-times more efficient than the previous model and offers more than double the cooling capacity. All totaled, cooling has been increased a substantial 33%.

The 2016 RXP-X 300 is available in Lava Red/Monolith Black Satin and White/Dayglow Yellow.

As to the supercharger, it too receives a boost in efficiency, thanks to a new compact fan wheel with double the blades (32) of the previous design and revolutions-per-minute increased by 8% to 47,000 rpm. Its shaft is thicker, and features additional clutch washers and bearing packs. Dynamically balanced prior to assembly, Sea-Doo now advertises the supercharger to be maintenance-free.

Do you feel the newfound power in a craft that was already one of the most potent performance machines on the market? Absolutely. While a handshake agreement with the Coast Guard will continue to see top speeds for all personal watercraft electronically limited somewhere in the neighborhood of 67 mph, you now get there much quicker, with the longer stroke improving torque and benefitting low-end acceleration, along with significant improvement showing up in the craft’s midrange. Throw the boat into the sharpest corner and rpm does not drop; skip across waves and you never feel the engine hesitate. There’s just abundant power, always at your fingertips.

Not for the faint of heart, the RXP-X 300 is ready to deliver on its promise of big power at all times.

More Aggressive

Thankfully, harnessing a lot of power is something the RXP-X has been designed to do from the start. Saying that the power stays on strong in the corners is significant, because this is arguably the hardest-cornering hull on the market. Dubbed the T3, for “tight-turning T-shape,” it loosely resembles the letter T when viewed from behind, with pronounced chines near the transom softening progressively as the design moves forward. At speed, the hull rides on a reduced running surface. Dive into a corner and the soft chines reward an inside lean. In fact, this hull leans so far as to warrant 90-degree winglets, similar to that you’d find on a slalom water ski, on its user-adjustable sponsons just to maintain contact with the water.

Sea-Doo’s T3 hull can carve a heck of a corner.

Such aggressive manners could easily overpower the rider, so at the same time Sea-Doo unveiled the ski in 2012 it also introduced a method to keep the driver in control. Dubbed ErgoLock, the now-familiar system narrows the center of the saddle in hourglass fashion, allowing riders to keep their legs much closer together. It adds padded bolsters that curve up and slightly over the thighs, and canted footwell wedges in the footwells to offer additional leverage and take stress off the knees. The final component is the adjustable handlebars, which can be fine-tuned for both width and angle. All together, the features literally change the way you ride, moving the stress of a tight turn from your upper body to your stronger leg muscles and positioning the rider in a more forward, aggressive position.

The RXP-X was never meant for a casual rider, but the newfound power – coupled with the familiar handling – positions the craft further into the upper echelons. Aggressive riders can literally push the craft to ridiculous limits. Settle the bow quickly via the electronic trim toggle on the left handlebar and you can turn corners so hard and fast that the craft puts up slalom-water-ski-style walls of spray. Raise the trim, shift your weight slightly back, and you’ll rocket past 65 mph in a blink. It’s a workout, for sure, but undeniably fun.

The RXP-X 300 can kick up a massive wall of water.

More Control

For all the power and handling, the RXP-X 300 remains civilized. This year sees the second generation of Intelligent Brake & Reverse introduced. iBR lets craft start in neutral, allows them to be “shifted” into forward, neutral, or reverse via a lever on the left handle grip, and rapidly slows the craft at speed should you encounter an obstacle. The second generation of the system responds much quicker, without the lag between motions felt in the original. It also further reduces stopping distance, and perhaps most welcome, greatly reduces the tendency of the bow to dive when applied at high speed.

Intelligent Throttle Control also returns, with riders able to choose between full-power Sport, slightly-tamed Touring, and fuel-saving ECO modes. All are easily accessed via buttons on the handlebars. One thing that is different on those handlebars is a new grip design. Featuring a pronounced flange that serves as a palm rest, it’s been integrated throughout the entire Sea-Doo lineup.

Sea-Doo’s eye-catching handlebars are largely unchanged, save for new grips.

Negatives? They’re few. That grip design may bother some people, though I quickly grew to appreciate it. Premium gas is required to get the full 300hp potential, but thanks to knock sensors the engine can happily run on 87 octane. The craft now weighs 38 pounds more, but in a hard-cornering hull such as this, settling that boat a tad lower into the water is hardly a negative. Given the additions, the $300 price bump to $15,199 is even relatively modest.

Overall, the RXP-X remains a fast and nimble beast. For the hardcore performance enthusiast who prefers the size and nimble feeling of a two-seater, it just may be the ultimate ride.