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Winterizing A Jet Ski: What You Should Know

Riding a jet ski (personal watercraft, PWC) is an exciting pastime for many people during the spring or summer months.

You can even ride in the fall and winter if you’re feeling ambitious and wear the right clothes.

But, if you live in a state where temperatures drop drastically in the winter, you’ll need to store your PWC with some attention to detail before the warmer months arrive. 

To winterize a jet ski for a few months isn’t particularly difficult, but it does take a little bit of extra work.

Due to the importance of winterizing your PWC, most manufacturers include instructions on how to store your jet ski in the cold.

But there are some basic protocols everyone can follow to protect your jet ski from brutal weather.

jet ski on the beach

Clean the Exterior

The first thing you want to do to winterize your jet ski is give it a thorough cleaning with warm water and soap.

Ideally, use marine soap to clean your PWC.

It will give it the most thorough cleaning and the best shine.

If you don’t have marine soap on hand, automotive detergent is the next best thing.

Avoid using household soaps, like dish or hand soap, on your personal watercraft.

Everyday soaps, especially dish soaps made to cut through grease, can wreak havoc on your PWC’s wax, opening it up for debris and damaging the hull.

When cleaning your jet ski, it’s important to elevate it so you can get at the underside.

The bottom of the hull is where much of the salt, vegetation, and general grime on a jet ski lives.

After a thorough rinsing, you can let it dry in the sun.

If it’s too cold or damp, use towels to gently pat the water from the surface.

Check the Wax

Before putting your jet ski away for winter, it’s a good idea to apply a fresh coat of wax.

If you’ve been riding all summer without stopping to apply fresh wax, it’s time for a wax job anyway.

Just like the soap, you can use an auto wax on your PWC if you’re in a real pinch, but it’s highly recommended you use an appropriate marine wax on your jet ski.

If you’ve let your jet ski air dry, be sure to run a soft cloth over the hull before applying wax to wipe away any dust that might have settled on it and ensure no dust particles gets stuck in the fresh wax.

Drain the Engine

Frozen engines are no good, which is why you should never put a jet ski away for winter without draining the engine first.

Water left in the engine can freeze, doing serious damage to the working components and making your PWC unridable come spring.

To drain the engine on your PWC, secure it to your trailer (or something else that won’t move if your trailer is, for some reason, unavailable) and turn it on.

Rotate the throttle backward and forward for a few seconds (around 15 or 20), let it rest for about a minute, then rotate the throttle again.

Do this for a few seconds a time, with minute-long rests in between, until water stops coming out.

In colder climates, you can hook a hose to the flush port and flush the jet ski engine with antifreeze.

Flushing with antifreeze ensures any water that gets left in the engine won’t freeze.

Drain the Fuel Tank

It’s always a good idea to drain your PWC’s fuel tank if you’re planning to store it for months at a time.

To drain, it’s helpful to have a fuel pump.

Simply connect the hoses to the appropriate places on the pump, put the intake hose into the fuel tank of the PWC and the output hose into a large enough bucket to capture the fuel, then turn the pump on.

Inspect Internal Components

So things that are already going wrong with your jet ski don’t get worse while it sits over the winter, check the wires around your engine, tightening any connectors that feel loose and replacing any connectors that are cracked or corroded.

It doesn’t hurt to add a little lubrication to anything on the PWC that moves (gears, levers, etc.).

Winter months are dry months, and lubrication will ensure components don’t turn brittle.

Remove the Battery

While you’re under your PWC’s hood, disconnect and remove the battery.

Like a car battery, a jet ski battery drains over time if you leave it sitting dormant.

Remove the battery just as you would a car battery.

Disconnect the negative terminal, then the positive, and lift out of the engine compartment.

Ideally, store your PWC battery in a case in an enclosed environment away from the coldest temperatures, such as an indoor garage or supply shed.

(Don’t store a battery inside your house. While the risk of danger is low, a PWC battery can explode (just like a car battery) if improperly handled. It’s best left outside the main living areas and untouched.)

Barricade and Cover

Tape over or stuff any open ports, outlets, or vents.

Unless you want a squirrel taking up cozy residence inside your jet ski or a rodent making easy work of your wiring.

Once you’ve fortified against unwanted intruders, cover your PWC with a specifically-designed jet ski cover or a tarp. 

Store in a Secure Place

If you don’t have a garage or shed where you can store your jet ski, you can store it outside, but you may want to take a few extra precautions (more lubrication, an extra tarp) and you must elevate it on a stand. (You should use a stand indoors too.) 

Instead, you may want to consider renting a storage space for your personal watercraft.

Many storage facilities have units specifically for small vehicles, so it may be cheaper than you think.

Conclusion

Before you put a jet ski away for winter, the PWC should have a clean exterior, well-oiled mechanisms, a few temporarily-removed parts, and a safe place to rest.

For information specific to your brand and model of PWC, consult the manual of your watercraft.

The steps above will get you to a largely well-winterized jet ski, but following the manufacturer’s advice is the best way to ensure your PWC makes it safely through the winter and is ready to ride come spring.