Kawasaki PWC fans will be more than familiar with the stellar offerings from our friends over at KSpeed. Their team has put together a truly wholistic set of goods and services set up to provide just about anything a Kawasaki owner might need: from instructional videos and manuals, to performance parts, repair services, and even insurance, they’re just about a one stop shop for all things Kawasaki. While we’ve talked about a wide array of their performance parts and accessories before, we wanted to take a moment to highlight one of their most complete packages: the KSpeed Stage 2 Kit.
As the name suggests, this is the second of KSpeed’s performance kits made specifically for the 2022+ Kawasaki Ultra 310 models. While the first stage pack was focused on removing speed limitations and improving agility and acceleration, the Stage 2 kit aims to deliver increase air flow, improved cooling, and potent low- and mid-range performance.
Of course, the magic is all a part of the various parts they’ve combined to get these results. For example, one of the most essential upgrades in the Stage 2 kit is the Intercooler BOV Block-Off Plate. When boost levels climb past 16.5 psi, the stock intercooler’s emergency relief valve (or BOV) starts venting excess pressure, essentially dumping the very boost you’ve worked to create. KSpeed solves this issue with a precision-machined block-off plate that replaces the OEM valve entirely, preventing pressure loss and ensuring every bit of boost stays where it belongs. It’s a simple modification that makes a big difference, especially when paired with a smaller supercharger pulley.
Speaking of which, the KSpeed lightweight billet pulley is another standout component. Crafted from aircraft-grade aluminum, it’s corrosion-resistant and significantly faster to spool than stock, giving riders that instant throttle response they crave. It’s compatible with all 310 Jet Skis, though a reflash is recommended (included with Stage 1 or available separately) to take full advantage of the added power. For the truly performance-minded, KSpeed offers a 108mm race-spec pulley, but this one’s strictly for experienced riders and racers. The smaller diameter means more boost (and more heat) so running fresh, high-octane fuel is a must. KSpeed also includes a new idler to help reduce belt slack and improve long-term reliability under high load.
Next up, the billet fuel rail—a beautifully machined, high-flow upgrade designed to fit the standard OEM injectors. Its larger internal diameter helps dampen pressure pulses, increase fuel volume, and ensure each cylinder receives consistent delivery even under hard acceleration. That consistency translates directly into smoother performance and the capacity for greater horsepower.
Then there’s the Atmospheric Trumpet, a fan-favorite among those who love both performance and sound. This clever addition reroutes hot, bypassed air out into the atmosphere rather than feeding it back through the airbox, lowering intake temps and giving riders that iconic “pshhhhtt” sound when backing off the throttle. It’s the kind of satisfying detail that performance enthusiasts appreciate—not just an upgrade you can feel, but one you can hear.
Finally, KSpeed recommends replacing your drive belt if your ski or belt has more than 50 hours on it before installing the Stage 2 Kit. The added power and boost put extra demand on the belt, and a fresh one ensures reliable performance. It’s also important to note that, while the Stage 2 kit can be fitted without the Stage 1, it works best when installed together.
All together, these components make the KSpeed Stage 2 Kit one of the most complete and thoughtfully engineered performance upgrades available for the Ultra 310 platform. From sharper throttle response and cooler operating temps to smoother power delivery and a more aggressive tone, this setup is designed to make the already impressive Ultra 310 feel like an entirely new machine.
You can check out the KSpeed Stage 2 Kit over on KSpeed’s website.
