How To Winterize A Jet Ski

A jet ski is a great way to enjoy the summer weather. For less than the cost of a full-sized boat, you can zip around a lake or a bay at twice the speed. But when summer comes to an end, you need to prepare your jet ski for the winter.

In extremely warm areas, “winterizing” might just be an expression. You may even have your jet ski tied to a dock, just waiting for the first pleasant day of spring. But if you are in an area where freezing temperatures are a possibility, you need to protect your engine and parts from the piercing cold.

We have compiled a quick guide on how to winterize a jet ski. Once completed, you will have all the necessary information to ensure that your personal watercraft is ready for the winter.

Clear Out The Storage Compartments

Before anything else, you want to begin by cleaning out all your storage compartments. Remove towels, sunglasses, and other gear you have been carrying around, and wipe out the inside of each compartment.

Leave the storage compartments partially open to prevent moisture and condensation from accumulating. If you are worried about critters nesting inside, a spritz of peppermint spray or a dryer sheet will keep them at bay.

Drain The Water

Jet skis rely on water in the lake, river, or ocean to keep the internal components cool. As a result, when you trailer your Ski-Doo, it will still have a fair bit of water inside. 

If left in place for the winter, the stored water can freeze, and the expansion will cause severe damage to your jets and other internals.

To clear this water, run the engine in short bursts until there is no more water coming out. Next, follow your manufacturer’s instructions for flushing your system. This method will remove any algae, silt, and other debris that may have been sucked into your jets.

Run Antifreeze

To ensure freezing temperatures will not damage your jet ski, run antifreeze through the cooling system. To do this, mix in a five-gallon bucket a 1:1 ratio of water and RV antifreeze mixture.

Run a short hose from the bucket to the flush outlet. Throttle the engine in short bursts until the solution has flowed entirely through the system. In this manner, the antifreeze mixture will replace any residual water.

Clean The Outside

With the interior components free of moisture, it’s time to turn your attention to the exterior of your personal watercraft. Wash down the hull, taking extra care to remove salt residue if you ride in saltwater.

Don’t neglect to clean the seat and controls. If they are kept free of algae, salt, and grime, they will last longer. When you have finished, apply a fresh coat of wax to the hull as an added layer of protection against moisture.

Lubricate And Stabilize

Cables and seals go unused over the winter, which leads to degradation. For seals, this means drying and cracking. For cables, it means rust and corrosion. Lubricate your seals and cables with the oil or grease recommended by your manufacturer.

Another thing to remember is that your fuel will degrade over the course of the winter. Ethanol gas attracts water, which builds up at the bottom of the gas tank. When you fire up your engine in the spring, the motor either stalls or fails to start.

To prevent this, add a fuel stabilizer to your gas tank. Then, run the motor for a few minutes to ensure that the stabilizer has been thoroughly mixed.

Apply Fogging Oil

Moisture isn’t just a concern inside the jets. Because of condensation, it can form anywhere inside your engine. You will need to apply fogging oil to your carburetor, cylinders, and spark plugs to prevent damage.

To do this, begin by removing the air filter. Then, treat the carburetor and cylinders. To get the best results, idle the engine, so the oil gets sucked in. Continue the process until the engine stalls out.

Next, pull all of the spark plugs, and spray inside each cylinder hole. Cover all the holes with a clean rag, and run the engine for a few minutes. The rag is there to prevent oil from being splattered everywhere.

This process is an excellent opportunity to check your spark plugs. If the plugs are dirty, clean them. If they are corroded, replace them. This way, you know you will be welcoming the next season with a good set of plugs.

Remove The Battery

When left connected, a jet ski battery will slowly drain over time. After a whole winter, you can easily find that your battery is completely dead.

To avoid this, simply disconnect the battery for the winter. Disconnect the negative terminal first, followed by the positive terminal. Remove it from the jet ski, and store the battery in a dry place and above freezing temperature.

Ideally, you would want to put your battery on a trickle charger for the winter. Also, consider storing the battery on a shelf, a mat, or an area guaranteed to stay dry. Never leave a battery directly on the floor.

Cover And Store Your Jet Ski

The most accessible place to store your jet ski is on its trailer. Remember to move the trailer every few weeks, even if you are just rolling it a few inches. This prevents flat spots and dry rot from taking hold. Alternatively, you can just remove the wheels for the winter.

Regardless of whether your trailer is indoors or outdoors, it’s still a good idea to keep a cover on your jet ski to protect it from dirt and dust.

Finally, it is essential to keep bugs and rodents from crawling into your engine or jets. Plug any holes with a sturdy, packable material like steel wool, and you will be all set for the winter!