Jet Ski Spring Startup
A Long Island De-Winterizing Checklist

After a full winter sitting still, a jet ski needs more than a turn of the key to be ready for the water. Fuel degrades, batteries lose charge, seals dry out, and small problems that started in the fall have had months to get worse. A proper spring startup catches those issues in the driveway — not a mile offshore. Here's the checklist we run every spring.

Your Spring De-Winterizing Checklist

• Battery — charge it fully or replace it if it won't hold a charge, then reconnect and check the terminals for corrosion.
• Fuel system — if the tank sat with untreated gas, the fuel may be stale. Add fresh fuel, inspect lines for cracks, and be ready for hard starting.
• Oil (4-stroke) — if you didn't change it in the fall, do it now. Old oil holds moisture that corrodes internals over winter.
• Cooling system — check for leaks and make sure the telltale ("pisser") stream flows once running; a blockage means no cooling.
• Impeller & wear ring — inspect for nicks, debris, or corrosion that developed over the off-season.
• Hull & drain plugs — confirm plugs are in and seals are intact before it ever touches the water.
• Safety gear — kill-switch lanyard, fire extinguisher (check the date), and current registration.

What Commonly Goes Wrong After Winter

It won't start. Almost always a dead battery or stale fuel. If the ski sat with untreated gas all winter, the fuel can gum up injectors and carburetors — sometimes a fresh fill is enough, sometimes it needs cleaning.

It runs rough. Gummed-up fuel delivery from that same stale gas. This is the single most common spring complaint we get.

No telltale stream. Debris or a wasp nest in the cooling passages over winter can block flow. Never keep running a machine that isn't peeing — you'll cook the engine.

Prefer We Handle It?

Spring commissioning is exactly the kind of job we do mobile — we come to your dock or driveway, run the full startup, and send you into the season knowing everything works. If you stored the machine with us over winter, we can de-winterize it before you even pick it up. See our full winterizing guide for what should have been done in the fall.