Skipping proper winterisation is the single most common reason jet skis need expensive engine work the following spring. It takes an afternoon and a handful of supplies — here’s the process in order.
1. Flush the cooling system
Run fresh water through the cooling system using the flush attachment, especially critical if you’ve been riding in saltwater. Any salt left sitting in the cooling passages over winter accelerates corrosion significantly.
2. Fog the engine and stabilise the fuel
Add fuel stabiliser to a full tank to stop the fuel degrading and gumming up the system over winter, then run the engine briefly to circulate it through the fuel lines. Fogging oil, sprayed into the air intake while the engine runs and again just before shutdown, coats internal engine surfaces to prevent corrosion during storage.
3. Change the oil
Old oil contains acidic combustion by-products that will sit in contact with engine internals all winter if left in. Changing it before storage, not just before the next season, protects the engine during the months it’s doing nothing.
4. Remove or maintain the battery
A battery left connected and unused will slowly discharge and can be damaged by a hard freeze. Either disconnect it and store it somewhere dry and above freezing, or leave it on a smart maintenance charger that trickle-charges as needed.
5. Cover and store properly
- Store on a trailer or stand rather than directly on the ground where possible
- Use a breathable, well-fitted cover rather than plastic sheeting, which traps condensation
- Keep it somewhere sheltered from direct sun and extreme temperature swings if you can
A jet ski properly winterised in fifteen minutes of extra effort each step almost always starts cleanly come spring — the machines that don’t are nearly always the ones that skipped one of these steps.
Need mounts, covers or electronics before you put yours away? Browse our jet ski accessories range, or ask us if you’re not sure what your model needs.