When it comes to driving plates for Kawasaki Ultra JetSkis, Jamie Eade, owner of Kspeed from Brisbane, Australia, has found the secret recipe (after many prototypes and countless hours of testing). The Watercraft Journal first reported on the details of the new KS3 ProRace Ride plate in April 2023, but only recently WCJ was able to get my hands on one for a practical test.
Kspeed’s original KS1 drive plate gained worldwide recognition, but was not compatible with the new Kawasaki Smart Reverse and Deceleration (KSRD) system, which is now standard on the new Ultra 160 and 310 JetSkis. So Kspeed went back to the drawing board and “reworked and refined the original design.”
The KS3 ProRace Ride Plate promises “a perfect blend of offshore and high-speed performance combined with improved handling in rough water conditions.” So, in two separate videos, JD Brussels of JD’s WaterWorld took to the water to test it out for himself on the Kawasaki Ultra 310 LX-S JetSki.
Die-hard Ultra fans don’t put much emphasis on calm water performance, so we ventured out to sea for the first round of testing. We all know that Ultra’s thick and durable SMC fiberglass hull is designed with a 22.5-degree break angle to cut through the waves, while Kawasaki’s patented Quattro Splash Deflector (QSD) efficiently and smoothly deflects swell and spray.
Many riders notice that the Ultra platform sits a little low at the bow. Even Kevin Shaw posted videos of a gold 2022 Ultra 310 LX “diving” at low speed. The KS3 ProRace ride plate corrects the Ultra’s tendency to “dive” at the bow by changing the way the water flows under the JetSki. This effect is visible even at lower speeds and gives the ski a “lift kit” feel.
Compared to the stock lift plate, which is 15 inches long and includes a 5-inch ramp area, the Kspeed plate measures 18 inches total. A large, sloped 8-inch ramp area provides aggressive lift even at lower speeds, while the Kspeed plate extends an additional 3 inches past the end of the jet pump steering/trim nozzle compared to the stock plate.
So why would someone choose an expensive skid plate over a comparatively cheaper pump wedge? A pump wedge creates a bow lift by changing the angle of the pump nozzle, thereby “bending” the jet and directing the water upwards – resulting in the bow sitting higher in the water.
Don’t get us wrong, Kspeed’s 2-degree pump wedge is a great option for anyone wanting more bow lift, but it comes at a price. By “bending” the water exiting the jet pump, you’re causing a small amount of parasitic loss.
By using a skid plate, you can maintain a neutral pump nozzle alignment and trim setting while still enjoying the benefits of a bow that is higher out of the water.
The JetSki literally glides on the larger surface area of the Kspeed driving plate – more of the deep V-Ultra hull protrudes from the water, contributing to less drag and allowing the boat to travel at higher speeds.
Raising and elevating the bow out of the water not only reduces drag, but also allows the Ultra to ride over wakes and waves more effectively.
Waves and wakes hit the ski directly on the bow rather than directly on the Ultra’s QSD spray guards, contributing to a drier, smoother ride for the operator.
As for calm water performance, JD recorded an average speed of 73 mph on 8 different speed runs. The Ultra 310 LX-S topped out at 75 mph at 8,000 rpm using the Kawasaki GPS Engine Information Display. JD is a 6’2″ and 215 lb rider and the ski contained 1/3 of a tank of 93 octane premium fuel. Unfortunately, JD was unable to test the skid plate on “glass” and the test was conducted during a 100 degree South Florida summer, so conditions were far from ideal.
As previously reported on The Watercraft JournalJD achieved a sustained top speed of 72 mph with the Kspeed Stage 1 kit alone; that means the Kspeed ProRace KS3 drive plate contributed to a 3 mph increase under similar test conditions. These results are consistent with Kspeed’s marketing claims and can be achieved with only moderate upgrades to your ski that won’t void your factory warranty or destroy your motor over time.
JD concluded that the KS3 ProRace ride plate “radically improves the ride characteristics of the Ultra 310” by “lifting the bow up and out of the water” and contributing to a drier ride overall. There is a clear trade-off between lifting the bow out of the water and hooking up the jet pump in the swell.
While JD did lose some contact in the wave action (as evidenced by the repeated screeching of the TVS supercharger at maximum rpm), ironically he claims he was still able to maintain a higher top speed with less fatigue while flying through the waves at nearly 55 mph off the coast of Jupiter Island.
For JD’s first test, he had installed both a Kspeed 2-degree Pump Wedge and the KS3 ProRace Ride Plate on his Ultra 310. JD felt that both were “a little to lots of lift” so he removed the 2 degree pump wedge and stuck with just the skid plate. The IJSBA Race-Legal KSpeed KS3 ProRace Skid Plate retails for $409 plus shipping. Note that this only fits 2022+ Kawasaki Ultra 310 JetSkis and 2023+ Kawasaki Ultra 160 JetSkis.
