How to Winterize a Jet Ski: A Beginner’s Guide

Winterizing and de-winterizing your jet ski is a chore, but avoiding a tricky situation on the water is well worth the effort. Taking the time to prepare your jet ski for winter and then reverse the process in the spring will keep your machine running smoothly and help you avoid any chilly surprises, just like putting on a warm coat before venturing out into the cold.

When I bought my first personal watercraft, I was mechanically challenged. But after a few hefty bills from the Jet Ski mechanic, I learned some tips to do it myself. Funny how money is a great motivator.

The most important reasons to winterize a jet ski include

• Preventing stale gas
• Keeping the engine from freezing
• Preventing moisture buildup in the fuel system

If you do not winterize your jet ski properly, the engine or other components may be damaged due to freezing or corrosion, resulting in costly repairs. Here are some basic instructions. Let’s Dive-in!

There will be some different methods, depending on the brand of PWC that you have. Sea Doo, Yamaha Waverunner, and Kawasaki all have little nuances, but these steps work for any personal watercraft you might own.

First, get your jet ski out of the water as soon as you finish your last ride of the season. Slowly back your vehicle down the ramp with your trailer securely attached until most of the trailer is underwater. Load your jet ski onto the trailer once it’s deep enough. Secure your straps no matter how far you travel.

Second, empty the exhaust system of any excess water. Bring your jet ski to where you intend to store it for the winter. I keep mine inside a garage. It would be best to do that for your Sea-Doo, Kawasaki, or Yamaha Waverunner. 

Check that the drain port at the back of the jet ski is open, and then start the engine for no more than five seconds. You will ruin your engine if you run it out of water for more than 5 seconds. During these five seconds, rev the jet ski several times. Tilt your ski back to ensure all water drains. Realign the jet ski for draining. To drain correctly, your PWC’s bow (front) must be higher than the stern (back).

Third, empty the fuel system. Drive the jet ski’s fuel to as low a point as you feel comfortable before trailering it out of the water. Feed a siphon hose into the fuel tank. I use a battery-operated fuel transfer device.

Fourth, replace the oil. Sea-Doo, Yamaha, and Kawasaki all recommend you use original parts. I have always followed their advice, but that does come at a price. Genuine parts cost more. I have a buddy who swears that the knockoffs do the same job. I never wanted to find out.

Check the owner’s manual to determine how much oil your jet ski needs. Drain the oil, replace the filter, and also replace the spark plugs. It sounds intimidating, but it’s pretty easy.

Fifth, refuel and lubricate your PWC.

When changing the oil, there are jet ski-specific products available, like XPS from Sea Doo itself. While somewhat costly, it eliminates a degree of doubt in the process.

Another critical step in winterizing a jet ski is to fill the gas tank to the top and add a stabilizer to keep it clean. Before adding a stabilizer to your fuel tank, read the directions on the bottle. To ensure the stabilizer is well mixed in the fuel, run the engine in 30-second intervals. Fogging oil should be sprayed into the carburetor and spark plugs.

Finally, flush the systems for two minutes with a (50:50) mixture of RV/Marine ANTI FREEZE and water. Ensure that the metal and moving parts are lubricated. Connect the funnel to the hose and the hose to the jet ski flushing port while the jet ski is level with the ground. Remove and store the battery in a dry place.

Winterizing your jet ski may appear daunting, but following these simple steps ensures that your watercraft remains in top condition during the off-season.

Clean the exterior with a scratch-free cloth to prevent critters from nesting in the exhaust before storing it. Remember that adequately winterizing your jet ski will extend its lifespan and ensure it is ready to ride when the weather warms up again!

When it comes time to de-winterize your PWC, the steps taken to care for it during its winter hibernation will also ensure that it starts readily when called upon to do so in the spring.

In summary, the 6 steps to winterizing a jet ski include:

1. Get the PWC out of the water as soon as the season is done
2. Drain the water out of the inside of the boat, especially its exhaust.
3. Remove the fuel and oil
4. Fill up the PWC with new fuel and oil
5. Add a stabilizer to the fuel to prevent any pest
6. Flush the system with anti-freeze

The last step goes without saying and, therefore, should be done without being added to a list. Wash the jet ski so that it looks good when the time comes to unleash it back on the water.