Why PWC winterization is its own animal

A Sea-Doo's exhaust system and intercooler (on supercharged models) trap water that outboards would drain by gravity. Freeze damage to an exhaust manifold or a cracked intercooler is a spring heartbreak that a proper fall routine prevents.

Procedure

1. Last ride / flush. Flush with fresh water using the flush port — and follow the golden PWC rule: engine running before water on, water off before engine off. Backwards order floods the engine through the exhaust.
2. Blow out the water. After flushing, a few short bursts of throttle (in short blips, engine off between if the manual says so) purge water from the exhaust. Follow the service manual's storage procedure for your model.
3. Antifreeze the exhaust loop where the manual recommends it — non-toxic antifreeze poured or pumped through the flush circuit protects trapped low spots, especially in climates with hard freezes.
4. Fuel: fill the tank (limits condensation), dose with stabilizer, and run briefly to circulate.
5. Oil change on four-stroke models — store on fresh oil, never used. Check the service manual for capacity.
6. Fog / storage-mist per the manual for your engine family. On supercharged models, note any supercharger service-interval items to schedule for spring.
7. Battery out, on a maintainer, terminals greased.
8. Interior: sponge the bilge dry, leave the seat cracked open for airflow, mouse-proof the exhaust outlet, and store slightly bow-high with the drain plugs OUT (tag the keys or the bars: "PLUGS OUT").
9. Lube cables and pivots; inspect the carbon ring/boot and the pump while it's convenient.

Common mistakes

• Flushing with the engine off (water walks up the exhaust into cylinders)
• Leaving the bilge wet and the seat sealed — spring mildew and corroded electronics
• Drain plugs left in outdoors: rain fills the hull, then freezes
• Forgetting to tell the customer their plugs are out — tag it visibly at the helm

When to walk away

If the engine hydrolocked from a bad flush before you arrived, do not crank it — pull plugs, assess for water and bent rods, and re-quote as a recovery job (see the submerged-PWC article).

Safety: run only with proper water supply and never stand behind the pump nozzle; fuel and fogging oil need ventilation; lanyard in your pocket when hands are near the pump.