How to Winterize a Jet Ski (and De-Winterize When It’s Time)

how to winterize a jet ski

Sadly, the warm days of summer are winding down and it’s time to think about putting your jet ski away until next summer. If your temps regularly drop below freezing in the winter, you will need to winterize it and store it properly to prevent damage and expensive repairs.

Here’s how to winterize a jet ski step-by-step and de-winterize it when the weather warms back up again.

Winterize a Jet Ski (Step-by-Step)

Be sure to check your owner’s manual for specific winterization instructions. Sea-Doo, Yamaha, and Kawasaki all have slightly different requirements, but the following general guidelines will guide you through the general winterization process step-by-step.

#1 – Drain Off Excess Water

Jet skis use water to cool the engine when the jet ski is in use. It’s important to drain off all of this water before you put your jet skin in storage for the winter. Moisture is bad news for anything you put in storage, and that includes personal watercraft.

To drain off any leftover water, elevate the front end of your jet ski. Turn the engine on for about 30-seconds and turn the throttle a few times. Turn off the engine and repeat the process until no more water comes out.

#2 – Consider Running Anti-Freeze Through the System

winterize jet ski

If your jet ski will be stored outdoors, consider running anti-freeze through the system before you put it in storage. This will prevent any remaining moisture from expanding and causing damage when temperatures plummet.

Simply mix a ratio of 1:1 antifreeze and water in a five-gallon bucket. Attach one end of a hose to the flush outlet and put the other end in your bucket. Turn the engine on and off until the solution passes through the entire system.

#3 – Fill the Gas Tank and Add Stabilizer

Storing your jet ski with a full tank of gas is essential for preventing condensation from forming inside your fuel system over the winter. Top off your tank and then add STA-BIL 360 Marine or other fuel stabilizer according to the directions on the product label.

Run the engine a few times at 30-second intervals to ensure that the stabilizer mixes with the fuel. A stabilizer is important for keeping the fuel from breaking down while your jet ski is in storage.

#4 – Lubricate Exposed Parts and Seals

Any seals, cables, or exposed parts on your jet ski should be lubricated according to the manufacturer’s directions. This step is crucial for preventing corrosion due to moisture over the winter.

#5 – Protect Your Carburetor and Spark Plugs

Protecting your carburetor and spark plugs from moisture is crucial for preventing corrosion. The best way to do this is to remove the air filter and spray the spark plug cylinders and carburetor with fogging oil. You’ll need to spray it down with the engine idling and keep spraying until it stalls.

Now, remove the spark plugs and spray each hole. Cover the holes with a rag and run the engine for a minute to ensure that the oil coats all of the internal parts.

Don’t be concerned if the engine doesn’t start at this point. Simply pop the spark plugs and air filter back into place and make note if your spark plugs will need to be replaced in the spring.

#6 – Store Your Battery Separately

jet ski battery winter

Your battery will drain over the winter if you leave it in your jet ski, so you’ll want to take it out and store it separately. Disconnect the negative terminal first, then the positive. Store the battery in a safe location that won’t drop below freezing.

If possible, hook it up to a trickle charger (Battery Tender is the best) to keep it topped off while in storage. Be sure to place the battery on a mat or some other elevated surface, not on concrete.

#7 – Protect Your Exhaust System

All sorts of critters will be looking for a protected place to ride out the winter, and your jet ski’s exhaust system is ideal. To prevent bugs and small rodents from crawling inside, cover the exhaust with steel wool.

#8 – Clean Out the Storage Compartments

The next step to winterizing your jet ski is to clean out the storage compartments. Once you’ve removed all your gear, give the compartments a good cleaning and then dry them thoroughly.

When you put your jet skin in storage, leave the compartments cracked open so moisture doesn’t get trapped inside. A quick spray with peppermint essential oil will deter critters from taking up residence.

#9 – Clean the Outside of Your Jet Ski

Now that all of your jet ski’s working parts are protected and the interior compartments are clean and dry, go ahead and give the outside a good cleaning.

It’s also a good idea to wipe down the seat, steering wheel, and any exposed rubber or vinyl with a protectant like Armor All before covering it for storage.

Related: How to Clean a Life Jacket

#10 – Cover Your Jet Ski and You’re Done

jet ski cover

The last step to winterizing your jet ski is to cover it and store it in a secure location for the winter. The easiest way to do this is to store it right on its trailer.

Cover the jet ski with a cover or tarp and you’re done. If you’re storing the jet ski in a garage or another enclosed area, don’t forget that it’s full of gas and may emit fumes during storage.  

Get Your Jet Ski Ready for Summer (De-Winterize)

When the weather warms up and it’s time to de-winterize your jet ski, you’ll want to start by charging your battery and putting it back in your jet ski. If you didn’t add a fuel stabilizer to your gas tank, the tank should be drained and filled with fresh fuel.

Next, drain the oil and replace it with fresh using the proper procedure for the type of engine you have. Keep in mind that a 2-stroke engine likely requires premixed fuel and oil, while a 4-stroke has separate tanks for each.

Now, grease and seal the bearings to ensure that everything is nicely lubricated when you start your engine. This will also keep sand and dirt from entering your engine and causing damage while your jet ski is in use over the summer.

Next, give all of the cables, wires, and belts on your jet ski a careful going over. Look for cracks and any other signs of damage. Replace any parts that appear worn and tighten any loose connections. Finally, switch out your spark plugs as needed and you’re ready to go.

See Also: Best Life Jackets for Jet Skiing

What Happens if You Don’t Winterize a Jet Ski?

jet ski ready for summer

If you don’t properly winterize a jet ski before storing it for the winter, you may have some expensive repairs to deal with in the spring. Moisture left in the engine can freeze, expand, and then crack key components engine, from hoses and seals to metal parts like the engine block.

If you didn’t stabilize the fuel, you may also have some issues with your carburetor. Be sure to pull and clean the carburetor before you start your jet ski for the first time in the spring. And, if the battery hasn’t been pulled and properly stored, it will need to be charged and maybe even replaced.

How Much Does Winterization Cost? (DIY vs Professional)

If you winterize your jet ski yourself, the cost will be minimal. You will only be out some time and the cost of lubricants, which shouldn’t be more than around $100.

However, if you choose to have a professional winterize your jet ski for you, it can cost $600 or more, depending on where you live.

One of the main benefits of having your jet ski winterized by a professional is that they will check it over for any potential issues that a novice may not recognize. And, of course, you will also have peace of mind knowing that everything has been done correctly.

Wrapping Things Up

Whether you decide to winterize a jet ski yourself or have a professional do it for you, ensuring that it’s done properly can save you a lot of expense and aggravation in the springtime.

The last thing you want is to pull your jet ski out when the weather gets warm and discover that you have a bunch of repairs to complete before you can enjoy it.

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