How To Flush A Jet Ski And Why You Should

Sun and water are the two worst things for any boat. This is a common joke that gets thrown around, but it’s funny because it’s true. The Sun is not forgiving, but water is attacking from another front, and it brings along corrosion.

Even in freshwater, your watercraft can and will corrode. Not just the outside, but the inside, as many models take in water to cool the engine. And Sea-Doo is not exempt with its closed-loop cooling, as it still takes in water for the exhaust and supercharger.

So, in this post, I’m going to dive into the nitty-gritty of engine flushing of jet skis. We’ll talk about when you should be doing it, the best times to do it, and I’ll even throw in a few handy tips I’ve picked up over the years.

Where Do You ride?

Where you ride your jet ski affects the steps and how often you should do an engine and exhaust flush.


If you ride your jet ski in saltwater or any dirty water, I suggest you flush after every ride or at the end of the riding day!!! It’s the standard for most boats that go in saltwater.

Once you’re done riding for the day, you need to hook up to a clean freshwater supply and flush it. (Clean water, as in tap water)

Fresh Water

If you ride in a lake or fresh water, flushing after every ride is not necessary.

It won’t hurt to do it after every ride if you like, especially if you’re going to clean it after every ride, but it’s not the end of the world if you don’t do it after a freshwater ride. (The average jet ski owner goes months not flushing their engine, they only ride in fresh water)

Important: Never flush a hot engine, allow the engine to cool down for 30 minutes before you flush it! Only flush for 90 seconds max!

Key Points:

The Reason To Do It

There’s a joke that “the two worst things for your boat are sun and water” it’s funny because it’s true. The reason you flush the engine and exhaust of a jet ski is that saltwater is highly corrosive, and can damage metal and moving parts.

Even freshwater can be corrosive, it’s just that saltwater is 100X worse, so freshwater tends to get a pass.

To prevent damage, it’s recommended to mist the engine compartment of your jet ski and pump area after flushing and avoid leaving your machine in the water for extended periods. Using a drive-up dock or lift is ideal.

How-To Video

Flushing most new and old jet skis is simple, but there are some important steps you must do to avoid hydrolocking your engine. These steps for flushing are best shown in a video like the one below.

Flush In Freshwater

If you want a simple way to flush the vital compartments of your jet ski, you can always take it for a short ride in freshwater, NOT saltwater.

Using a garden hose will be the best way to flush your own personal jet ski, but it has its risks if you do the order wrong. So, if you’re unsure, a quick ride in freshwater is a super easy way to flush most jet skis.

Mist The Engine Compartment

After a saltwater ride, you should flush and also mist the engine compartment and rinse the pump area of your watercraft.

Make sure to remove the drain plugs when cleaning the engine compartment, and then put them back in before you ride!

Tip: Once a month, I suggest spraying “silicone lubricant (Amazon Link Ad)” on the engine and pump area, anything metal, electrical or shiny. You should do this for sure if you ride in saltwater, but if you ride in freshwater, you can do it at the start and end of the riding season.

Failure To Do It

Failure to flush will lead to metal parts corroding and even phantom electrical PWC problems down the line.

The picture below shows a Sea-Doo that was not properly flushed or maintained after numerous rides in saltwater.

As a result, it suffered extensive damage.

The deterioration was so severe that the green antifreeze in the ride plate began to leak through the corrosion holes.

corrosion from salt water for jet ski

The jet pump is made of mostly metal, and while it’s painted, corrosion still finds a way.

How To Stop Corrosion

Keeping your watercraft in great condition, especially after riding in saltwater, is simpler than you might think. The best approach is to flush and rinse it off after every saltwater ride. This really helps in preventing corrosion.

Did you know that manufacturers include something called a “sacrificial anode” in their designs? It’s a clever little part that’s designed to corrode first, protecting the other metals. But it’s important to keep an eye on this anode. Regularly check to make sure it’s still there and in good shape. If it looks worn out or damaged, it’s time to replace it.

Typically, there are one or two sacrificial anodes on most watercraft, and you’ll find them near the jet pump. You won’t find any in the engine compartment, so a good practice is to spray this area with silicone lubricant for extra protection.

Taking these small steps can really extend the life and performance of your watercraft.

Don’t Forget To Rinse The Trailer

When rinsing your personal jet ski with the garden hose, also rinse the trailer.

Trailers, even aluminum ones, can corrode on steel parts, especially the hardware like screws and bolts that hold everything together.

Rinse your metal jet ski trailer after saltwater use and every so often for freshwater.



I started working at a power sports dealership in 2007, I worked in parts, service counter, and as a technician before moving to sales in 2013. I created in 2014 to answer common watercraft questions I would get from people. Now managing the site full-time, I continue to provide advice and web tools for my readers about watercraft. I've owned several watercraft, with a Sea-Doo Spark as my current main PWC.

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