Compare Specs Discover '24 PWCs Browse Reviews
How to De-Winterize a Jet Ski in 10 Simple Steps [Guide]

How to De-Winterize a Jet Ski in 10 Simple Steps [Guide]

The jet ski de-winterizing procedure is just one of the many important maintenance duties your jet ski needs.

To make sure you wake up your jet ski from hibernation properly and prepare it for the season, you have to check it carefully and do some basic maintenance.

If you want to know how to de-winterize a jet ski by yourself, this post is for you.

We, at JetDrift, have gathered the required steps into this step-by-step guide. Although this process isn’t too complicated, it’s recommended you refer to the owner’s manual before you start!

What Does De-Winterizing a Jet Ski Mean?

Jet ski de-winterization is a required maintenance procedure that you need to do every year after the off-season, and before your first ride. Known as PWC Preseason Preparation as well, jet ski de-winterization includes some important steps which are necessary to ensure every part of your jet ski is working properly and securely.

How to De-Winterize a Jet Ski

To de-winterize your jet ski properly, you have to remove the cover and the seat first. Then charge and install the battery, lubricate the moving and metallic parts, flush the cooling/exhaust systems with running water, and clean the hull if it’s needed. You may also want to check the whole jet ski carefully to make sure all features work. Finally, add the required accessories and documents in the storage compartment. 

This is jet ski pre-season preparation in a nutshell, but if you’d like to learn more about each step, don’t stop reading here!

Step-by-Step Jet Ski De-Winterizing Guide

Installing the Battery

If you stored your battery properly for the winter months while attached to a battery tender, it should be fully charged and in good condition.

If it’s not, charge it carefully and do the other maintenance on it if needed.

This usually means filling the battery up with distilled water (in case of regular flooded-acid batteries) and remove corrosion from the terminals.

Before you reinstall it, you may want to check it with a battery tester to make sure it’s in perfect condition. If it’s been charged but it’s still dead, you need to buy a new battery.

Secure the battery in its place, then clean and grease the leads. And while you reattach the cables, make sure to attach the positive (+) red cable first to the positive terminal!

If you have a flooded-acid battery, don’t forget to attach the vent hose.

Checking the Engine

Since the engine is a key part of the machine, it deserves a thoughtful inspection while you de-winterize your jet ski.

Check the engine oil to make sure it’s in level, ensuring that it didn’t leak leak out of the engine during the off-season.

If you haven’t changed the engine oil before the winter (which is highly recommended) it means you have to replace it now and the filter as well.

Flushing the Jet Ski

The next step is to attach a garden hose to the flushing port and start the engine. Don’t forget, you have to start the engine first, just after you turn the water on!

Run the engine for 2 minutes to check that everything works properly, and also check the engine compartment for leaks.

It’s very important to run the engine only at idle speed, as the valves don’t like higher RPMs during the first start!


Thoroughly examine all the main parts and features. It’s recommended you inspect the following units and systems as part of the de-winterization procedure:

  • Level of other liquids (coolant, etc)
  • Steering
  • iBR/RIDE system
  • Pump/Impeller
  • Trim
  • Fuel line
  • Hoses and connections

    Wires and electrical connections

  • Bilge Pump
  • Horn
  • Speakers
  • Bolts and nuts
  • Gauges/LCD screen
You’re looking for any damage, indications of wear and tear, cracks, and anything loose.

Anything that looks worn or damaged should be replaced and make sure that everything else is properly secured or tightened.


If everything works properly, it’s a good clue that your ski is in good condition and ready to go.

But before you put it on the water, you may want to lubricate the moving and metallic parts. Use an anti-corrosive lubricant to spray the required parts to protect them from corrosion.


After the lubrication and inspection, you can consider cleaning the jet ski if necessary.

If you cleaned it before the off-season storage and stored it in your garage with the cover on, it means it’s still probably pretty clean. But a thoughtful check never hurts!

Adding Accessories

Don’t forget about the accessories; make sure all of them work and are in good condition.

Double-check the life jackets, safety lanyard, GPS, VHS radio, and other safety accessories, as they can be life-savers on the water!

Tip: Don’t forget to check the expiration date on the fire extinguisher!Make sure all of the required and necessary equipment are in your ski before you hit the water!


Moreover, don’t forget to keep your documents onboard:

Check the Trailer

When it comes to jet ski de-winterization, the trailer is often overlooked, as it’s usually not mentioned in the jet ski’s owner’s manual. Nevertheless, it’s highly recommended to check the trailer carefully:

  • Check the frame
  • Check and inflate the tires if needed
  • Make sure the lights work properly
  • Fix all problems – if you find any
Never overlook the trailer’s maintenance, as a rusted frame may end in an accident on the road!

On the First Ride

When it comes to the first ride after de-winterizing your jet ski, never ride it full throttle just after you launch it.The best practice is to let the engine run at least 4-5 minutes at idle speed. You may also want to ride it carefully for a couple of minutes to make sure every feature works properly.

It’s not only your engine, but probably your skills also need a little warm-up after the long winter months!


As you can see, de-winterizing a jet ski is not rocket science. Thus, you can do it easily by yourself if you follow these 10 simple steps:
  • Remove the cover and the seat
  • Charge and install the battery
  • Check the engine and the liquids (oil, coolant, etc.)
  • Flush the cooling/exhaust systems with fresh water
  • Inspect the features and parts
  • Lubricate the metallic and moving parts
  • Clean the jet ski if needed
  • Check the trailer carefully
  • Add the accessories and documents
  • Start your first ride slowly carefully
These are the most general steps of de-winterizing, but keep in mind that each jet ski is different.

Because of this, you have to refer to your jet ski’s owner’s manual before you start the de-winterization procedure (or any other maintenance) by yourself!