Riders walk in regularly wanting to go faster. That's a reasonable goal. But the conversation usually starts with something they saw in a forum — a specific part, a specific number, a claim that sounds more dramatic than what we observe on the water. This article is the honest version of that conversation.
We tune Sea-Doo, Yamaha, and Kawasaki regularly at AOG Performance. Here's what actually works, what the realistic gains are, and what you can skip.
ECU Tune: The Highest Impact Starting Point
Every manufacturer tunes their ECUs conservatively. The fuel maps are slightly rich, the timing is pulled back from optimal, and the rev limiters are set lower than the engine can comfortably handle. This is partly liability management and partly leaving room for market differentiation between model tiers.
An ECU reflash — also called a tune or a flash — changes those parameters. On a supercharged machine like the Sea-Doo RXP-X 300, Yamaha FX SVHO, or Kawasaki Ultra 310R, the engine responds well because the supercharger means there's already significant airflow. Leaning the fuel map slightly, advancing timing, and removing the rev cap where the engine is comfortable doing so extracts real horsepower.
On naturally aspirated machines — VX Yamaha, GTI Sea-Doo — the gains are real but smaller. Throttle response improves noticeably, the mid-range feels stronger, but you're not going to add 10 mph to a naturally aspirated ski through an ECU tune alone.
Realistic expectations on a supercharged ski: improved throttle response that you feel immediately, better pull through the mid-range, and a few more mph at the top end. Not 15 mph. Usually 3–6 depending on platform and what else is done.
Impeller Upgrade: The Best Mechanical Mod
Stock impellers are a compromise. They're pitched to work across a range of rider weights and riding styles without being optimized for any one. An aftermarket impeller — especially a stainless steel unit — changes two things: top speed potential through higher pitch, and acceleration through pitch matched to your riding weight.
Stainless holds pitch better than cast aluminum or composite in abrasive saltwater conditions. A properly pitched stainless impeller on a Sea-Doo RXP-X 300 or Kawasaki Ultra 310 makes a difference you feel every time you open the throttle. Combined with a new wear ring (which should be done at the same time), most riders notice improved hole shot and measurably better top speed.
The key word is "properly pitched." An impeller that's pitched too high for your engine and weight will bog on acceleration. Too low and you're leaving top speed on the table. We match the pitch to the ski, the engine output, and the rider — that's what makes the difference between a mod that works and one that feels like it didn't do anything.
Intake Grate: Handling and Efficiency
The intake grate is what sits under the ski and controls how water enters the pump. A better-designed intake grate improves water flow into the pump, reduces ventilation (air ingestion) in tight turns, and on some platforms makes a measurable difference in straight-line efficiency.
Racing-style grates improve handling noticeably in corners — less blowout, better predictability when pushing the ski into a turn. They don't dramatically increase top speed on most production skis, but they change how the ski feels in real-world riding conditions. For riders who do a lot of maneuvering rather than just straight-line speed runs, this is a worthwhile modification.
Aftermarket Exhaust
Exhaust is where expectations often outrun reality on jet skis. Unlike motorcycles or cars where a full exhaust system is a significant power gain, jet ski exhaust systems have less dramatic results on most modern platforms. The reasons are engineering-specific to how the exhaust route and water injection cooling work.
That said, on certain platforms — particularly the supercharged models where the engine is already flowing a lot of air — an aftermarket exhaust does change the top end character, allows the engine to rev more freely, and contributes to the overall picture of a performance build. It's a supporting modification, not the headliner.
We'll tell you honestly whether it's worth it on your specific ski before you spend money on it.
What Doesn't Work the Way You Hope
Bolt-on air intake modifications on most modern closed-loop fuel-injected skis don't do much on their own. The ECU compensates, and without a matching tune, you're not getting meaningful gains. Sponsons and trim systems improve handling but don't add speed. Larger fuel tanks don't increase power (but they do extend range, which can be genuinely useful).
The modifications that work best are mechanical ones — impeller, pump work — combined with the ECU tune that tells the engine how to use the additional flow efficiently. The package matters more than any single part.
The Right Approach
Tell us what you want to accomplish and how you ride. If you want more top end, we build for that. If you want better acceleration and hole shot for a specific weight and riding style, the package is different. If you want the most reliable daily-rider build that's also fast, that's another conversation.
We don't spec builds from a parts list — we build from your goal. If you're ready to talk about performance tuning, give us a call at (347) 225-5113 or shoot us a message through the contact page. We'll give you a straight answer about what's realistic on your specific ski.