How To Winterize Your Jet Ski For Winter Storage

As the chill of winter sets in, it’s a good time to start thinking about the winterize process for your jet ski. I know it’s not the most fun thing, but something that needs to be done for most jet skis.

It’s a super important process, especially if you live somewhere that gets below 40F/5C! You’ll be surprised by the number of people who simply forget about winterizing their jet ski, so please make sure to not forget!

Note: This post will tend to be more geared towards Sea-Doo, but it’s just about the same for Yamaha and Kawasaki jet ski.

What you need:

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

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

How to Winterize A Jet ski!

The process involves adding fuel stabilizer, flushing the jet ski with antifreeze, fogging the cylinders. Also disconnecting the jet ski battery, and greasing some components.

Here is a great video showing the process.

If you’re like me, you need written steps, 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 jet ski sits. The fuel stabilizer bottles generally include measurements suitable for a gas tank ranging from 2.5 to 20 gallons. A jet ski will have 5 to 20 gallon gas tanks, often 15 to 18 are the most common.

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

You’ll add the fuel stabilizer to your jet ski 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 the most important step, it involves removing the water from the jet ski engine and exhaust system!

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

1. Level the jet ski to the ground.
2. Connect the drill pump to the jet ski’s flush port and get the antifreeze ready.
3. Turn the jet ski 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 jet ski 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 compressed air for removing any water, but I prefer to use marine antifreeze. I find it drill pumps easier for people than an air compressor.

Add water? For the Marine and RV antifreeze 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 Jet Ski Engine Parts

The third step involves the jet ski engine and fogging it.

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

Fogging your jet ski 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 jet ski:

At the start of the jet ski 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 smart battery chargers that manage charging automatically. Alternatively, charge the jet ski battery 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 my 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 the 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 process annually, allowing air drying for 15 minutes each time, and your jet ski will maintain its appearance for years!

6: Put The Cover On

Do not leave the cover off your jet ski after winterizing it, this is an 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 jet ski.

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

Please consider shrink wrapping to better protect your jet ski. Shrinking wrapping keeps your craft in near perfect condition; snow and rain won’t affect it. Any little thing you can do will help. Snow, rodents and rain love to attack boats and jet skis, try to do something as anything is better than nothing.

How to de-winterize a jet ski

At the end of winter, you’ll need to get your jet skis 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 jet ski battery.
2. Replace spark plugs.
3. Top up the gas tank with fresh gas.
4. Ride the jet ski.

Note: If you take the jet ski 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.