How To Winterize Your Jet Ski For Winter Storage

As the cold weather rolls in, now’s the perfect time to start thinking about winterizing your jetski. It might not be the most exciting task, but it’s something that needs to be done for most jet ski.

Winterizing is especially important if you live in a place where temperatures drop below 40°F (5°C). You’d be surprised by the number of jetski owner’s forget this step; so please don’t forget!

Note: These how to winterize steps focuses on Sea-Doo models, but the process is nearly the same for Yamaha and Kawasaki jet ski too.

A Checklist of What you need:

You’ll need to get some items for your jetski that will be used for multiple years.

1. 1-Gal (per machine) of RV/Marine Antifreeze.
2. A marine fuel and gas stabilizer.
3. A fogging spray storage oil.
4. A WD-40 Silicone spray lubricant or similar product.

How to Winterize a Jet ski!

The winterize process involves adding fuel stabilizer, flushing the jetski with antifreeze, fogging the cylinders. Also, it’s good to disconnect the battery connections, and grease some components.

Here is a great video showing the process.

If you’re like me, you need written instructions on how to winterize a PWC, so I’ve listed them below.

1: Add Fuel Stabilizer

The first step is adding fuel stabilizer for the gas tank to keep the fuel in great shape as the jetski sits. The fuel stabilizer bottles generally include measurements suitable for a gas tank ranging from 2.5 to 20 gallons. A jetski will have 5 to 20 gallon gas tanks, often 15 to 18 are the most common.

If you’re wondering if the jetski fuel tank should be full or nearly empty, it’s your pick.

You’ll add the fuel stabilizer to your jetski tank first, it ensures it mixes well and reaches all the fuel lines, before starting the next steps.

2: Flush With Antifreeze

The second step is a important step, it involves removing the water from the engine and exhaust system!

The way you remove water from a PWC engine is by using marine-grade antifreeze. Below, I’ve listed the winterize steps to flush a PWC engine with marine antifreeze.

1. Level the PWC to the ground.
2. Connect the drill pump to the PWC’s flush port and get the antifreeze ready.
3. Turn the engine on.
4. Turn on the drill pump and use the entire gallon of antifreeze.
5. When you use up the whole gallon of antifreeze, turn off the drill pump, then switch off the PWC engine.

You want antifreeze coming out the exhaust, nozzle, jet pump area, or the side discharge port. If you don’t see antifreeze come out of ONE of these ports after 20 seconds, turn the pump off and then the engine off, as something is not working right!!! Video below:

The owner’s manual suggests using a air compressor for removing any water, but I prefer to use marine antifreeze. I find a drill pump easier for people than a air compressor.

Add water? For a Marine and RV antifreeze it should come pre-diluted and ready. Additionally, water remains in the cooling system of your jet ski; hence why do the whole winterizing, as it inevitably blends with water. So, adding more water into your jug is not what we want.

3: Coat & Fog Internal Engine Parts

The third step involves the jetski engine and fogging it.

The reason to fog engines is to coat a few internal metal components to prevent rusting during periods of inactivity.

Fogging a engine requires you removing all spark plugs and spray fogging oil into each cylinder for about 3 seconds. The video below shows you how to fog the engine:

At the start of the riding season, I suggest replacing spark plugs because of the effect of the fogging oil.

4: Remove jet ski Battery And Charge It

The reality is that a jet ski battery will go flat during the winter of inactivity, so it’s to our best judgment to remove it and keep it dry and above freezing, or we run the risk of a dead battery next jet ski riding season.

Ideally, use a smart battery charger that manage charging automatically. Alternatively, use a charger every other month.

Will you have a dead jet ski battery if it doesn’t get charged over winter? Maybe. A big complaint at the start of the season I get from people is that their jet ski won’t start, and it’s because of the battery. Your jet ski’s battery are small and don’t get used enough, leading to them dying. A battery charger proves effective in maintaining battery life throughout the cold season. What I like to do is get a solar charger, as I keep my ski outside and get 5 years out of my batteries.

The solar charger doesn’t need direct sunlight and will keep a jet ski battery active and happy! It’s so stupid easy and effective that I don’t know why the jet ski manufacturers don’t just have the solar panels already on the covers?

5: Spray WD40 specialist Silicone Lubricant

A commonly overlooked step is spraying WD40 silicone spray lubricant on all metal and electrical parts of the jet ski, including the engine and pump area.

Make sure to let the jet ski sit for 15 minutes and air out because that stuff is a fire hazard!!!

Also, lubricate the jet ski’s throttle and steering cables with marine grease.

Avoid regular WD-40, use a silicone version. The regular stuff doesn’t coat, it merely displaces water.

Here’s a useful tip for those residing near saltwater: regularly apply silicone spray on engine and pump areas. Repeat this as a yearly routine, allowing air drying for 15 minutes each time, and your PWC will maintain its appearance for years!

6: Put The Cover On

Do not leave the cover off your PWC after you winterize them, this is a very important step! The cover keeps the snow and more importantly, rodents, spiders and other critters from getting in and eating or trying to destroy your PWC.

Rodents like the taste of rubber and plastic, so put a cover on the cover, if you ask me.

Please consider shrink wrapping to better protect your PWC. Shrinking wrapping keeps your PWC in near perfect condition; snow and rain won’t affect it. Even a little can help. Snow, a rodent and rain love to eat the plastic and rubber of a PWC or boat, try to do something as anything is better than nothing.

The Steps to de-winterize a PWC

At the end of winter, you’ll need to get your PWC ready for the summer.

The process is super simple, I bet many of you have done it without realizing it.

Below are the steps, but I’ll link to the full guide, too.

1. Charge the battery.
2. Replace spark plugs.
3. Top up the gas tank with fresh gas.
4. Ride the PWC.

Note: If you take the PWC out after you, it will need to be winterized again. As soon as the engine is run in the water it’s not winterized anymore.

Learn more about this process, see my post here.