How to Remove Corrosion from Your Jet Ski’s Engine

I hope you’re ready for a chemistry lesson today because it’s time to talk about one of the most common jet ski maintenance plights there is: engine corrosion. 

How to remove corrosion from your jet skis engine?

Prevention is the best weapon against engine corrosion. You can prevent your engine from corroding by keeping it dry and well-lubricated so that water doesn’t get to the rustable metal parts. If you have to remove it, try steel wool, a metal brush, or chemicals to aid in removing any rust. Always use a preventer after riding such as Corrosion X or Yamashield.

Engine corrosion is a big deal if you own a jet ski.  Jet skis aren’t cheap to begin with, and as jet skis become more powerful, their engines become bigger and more expensive.  That’s why it’s so important to take care of your jet ski, particularly its engine, with regular maintenance. If you don’t, you risk extremely costly repairs and in extreme cases, you may even have to replace your whole engine. 

However, if your attempts at preventing rust development have failed, you can remove most corrosion stains from your jet ski’s engine at home with either commercial cleaners like Corrosion X or natural household cleaners like vinegar and a nylon brush. 

Jet Ski Corrosion 101

Corrosion is a natural, albeit frustrating and potentially costly process that affects metal surfaces, like your jet ski’s engine. To understand the conditions that cause your engine to corrode and how to prevent corrosion, it’s important to first discuss what corrosion is. 

What is corrosion?

Corrosion is a chemical reaction that occurs when metal, like iron, is exposed to water and air (oxygen) and becomes oxidized.  In the case of iron/steel, which is what most jet ski engines are made out of, this exposure creates a new chemical compound called iron oxide, also known as rust.  

If you remember much from your high school chemistry class, you might recall that a chemical reaction is a process whereby the molecules in a substance rearrange and undergo a permanent transformation.  In the case of rust formation, the molecules in iron mix with the molecules in air and water and re-arrange to create rust.  

This is important to remember because you need to understand that rust doesn’t appear out of nowhere. It comes from a chemical change that has happened to the metal. Although we can remove this rust, we can’t reverse the chemical change that has occurred, so, if your engine continues to experience corrosion, it will eventually break down the metal so much that the engine no longer functions properly.  This is why it is so important to prevent corrosion whenever possible. 

What causes jet ski engines to corrode? 

Unfortunately, the natural conditions of jet ski usage are the exact conditions that lead to corrosion.  Remember, Water + Air + Iron = Rust.  And where do jet skis operate? That’s right, in water.  Because jet skis are so regularly exposed to water, they WILL corrode no matter what over time, especially if proper care isn’t given to rustable parts like the engine. 

If you ride your jet ski in saltwater frequently, the corrosion is likely to occur even faster. This is because salt acts as a catalyst that speeds up the chemical reaction leading to rust.  

How to Prevent Corrosion

At this point, you’re probably beginning to wonder if it’s possible to prevent corrosion from happening, and luckily, it largely is.  Although over the course of your jet ski’s life you are probably going to see at least mild corrosion at times, there are several ways to prevent significant corrosion from damaging your engine: 

  1. Pre-Season—Spray the engine with a corrosion inhibitor.  At the beginning of the riding season, while your jet ski is at its driest, spray the entire engine (don’t forget the underbelly), with a corrosion inhibitor like Yamashield or CRC
  2. After Riding in Salt Water—Flush the system with fresh water. After each use in saltwater, follow the instructions in your owner’s manual for flushing the cooling system and engine compartment with fresh water.  Up your game by adding Salt Away to the flush water. Salt Away strips the salt from your engine so it doesn’t linger and corrode the engine over time.  
  3. Always—Keep it dry. You’re not going to be able to keep the interior of your jet ski completely dry while riding it because of how the open-loop cooling system of most jet skis works.  But there are several things you can do to prevent water from affecting the engine or other metal parts of the interior.  First, always remember to check your drain plugs. Forgetting your drain plugs is the fastest way to accidentally flood your engine compartment with water.  Second, avoid flipping the jet ski at all costs, as flipping it will cause the engine compartment to be flooded with water. Lastly, when you’re done riding/flushing the cooling system, dry the entire jet ski off completely. Remove compartment lids, sop up any visible liquid and wipe down or let air dry between uses. This is also why we don’t recommend storing your jet ski in the water unless you have a lift or drive on dock. We have seen many jet skis get flooded with the waves due to this.
  4. When Storing—Fog the engine. Lastly, if you won’t be riding your jet ski for several weeks or longer, consider fogging the engine while you flush the system.  This extra lubrication step prevents water from getting to the metal components of your engine. Fogging oil is easy to get online.  

You may or may not be curious about why these methods work to prevent corrosion, but in either case, I think it’s worth understanding the chemistry behind them.  Think back to our basic equation: Water + Air + Iron = Rust. To prevent the rust from forming, you have to remove one of the components of the equation, i.e. water or air. If your engine has been exposed to saltwater, you also need to remove the salt, which speeds up the corrosion process.  

This is the rationale behind flushing the engine with fresh water, then properly drying and lubricating it.  The freshwater subtracts the salt, the air subtracts the water, and the lubrication prevents the water from reaching the metal (remember, water and oil don’t mix). 

Painting, plating, and galvanism are also ways of preventing rust because they add an additional element to the metal’s surface that prevents the oxygen and water from attacking the metal.  This is the science behind galvanized steel (which adds a layer of zinc to the iron alloy) and stainless steel (which adds a layer of chromium), which is why we recommend that if you purchase a steel trailer, you opt for galvanized or aluminum if you’re going to primarily be around saltwater. Some people will actually paint or galvanize parts of their engine to prevent rust from forming, but we recommend consulting a licensed dealer before attempting to do so yourself. 

If you’re more of a visual person, check out this great video that explains the process of rust formation under different conditions and how to prevent the formation of rust on metal surfaces. 

How to Remove Corrosion from your Jet Ski’s Engine

Mild rust is to be expected over time, so it’s a good idea to know how to remove corrosion from your jet ski’s engine. Resolving mild to moderate rust issues at home is fairly simple, it just takes a few products and tools plus a bit of elbow grease.  If you don’t feel comfortable removing rust on your own, you can take it to a dealer/repair shop, but you’ll likely shell out a couple hundred dollars for them to do it for you. 

There are two ways to remove rust: physical and chemical. We recommend you use a combination of the two:  

Step 1: Spray/coat the engine with something that will break down the rust. (This is the chemical part of the rust removal process.)

  • Commercial Cleaners: Some great commercial rust removers to try are Corrosion-X and CLR Pro Cleaner. 
  • Natural Cleaners: There are also some natural products you likely already have at home that can be used to clean off rust, such as vinegar (you can use regular white vinegar, but I really like cleaning strength vinegar like this one) or baking soda and hot water. 

Step 2: Wipe/scrub to remove the rust. (This is the physical part).

  • Read the directions on whatever cleaning product you use, but even if it just says to wipe the product off, most rust removers will still require a little bit of elbow grease to fully remove the rust.  Use a nylon or stainless-steel brush to scrub the rust off.  Note: You might be wondering about using sandpaper, steel wool, or a regular wire brush to scrub off rust.  These products can work well, but if you use them, you need to be extremely diligent about adequately rinsing the engine and engine compartment afterward, or the residue they leave will rust the next time you use the jet ski in saltwater. 
  • You may have to repeat Steps 1 and 2 a couple of times if the rust is really bad.

Step 3: Rinse and dry well. 

  • Once you are satisfied with the rust removal, you need to rinse the cleaner, rust particles, and residue off the engine and out of the jet ski.  Do not be lazy with this step. The entire engine compartment needs to be cleared of the rust or you will get rust stains in other areas. 
  • Then, make sure the engine is dried off completely.  When the engine is dry, if you notice any other rust spots, you can also use sandpaper to sand off the rust. If you do this, be sure to rinse the engine again afterward. 

Step 4: Lubricate the engine with a rust inhibitor. 

  • Once the engine and engine compartment are COMPLETELY dry, spray the engine with a corrosion inhibitor like the ones listed in the rust prevention section above. If you won’t be riding for a while, you can also fog the engine at this point. 

Once you’ve successfully removed the corrosion from your jet ski’s engine, be sure to diligently follow all rust prevention strategies listed above to prevent more rust from forming. Preventing rust from damaging your engine will give your engine a much longer life.  A well-maintained engine can easily go well beyond the standard 400-500 engine hours most people will quote as the standard life of a jet ski engine. 

Other Jet Ski Parts/Accessories Susceptible to Rust

Your jet ski’s engine is not the only part of your jet ski that you have to worry about rusting. Any other parts you have that are made from iron or steel (which is an iron alloy), will rust when exposed to water and air.  This can include bolts, screws, spark plugs, O-rings, hose connectors, metal fans, etc. Also, don’t forget about the metal components in your accessories, such as your jet ski’s trailer, particularly if it’s made from steel.  These are also susceptible to corrosion.  Apply the same prevention and removal strategies to these parts and accessories as you would the engine. 


Iron and water don’t mix well, or rather they do, but they cause rust to form and corrode the metal, which is something you really don’t want to happen to your jet ski’s engine. This is why it’s so important to take preventative measures like lubricating your engine and keeping your jet ski out of the water and dry between uses. 

However, even jet ski owners who are diligent in their maintenance and cleaning routines will probably encounter mild bouts of rust from time to time. When this happens, remove corrosion from your jet ski’s engine with a commercial or natural cleaner and a nylon brush. If this doesn’t remove all the rust, sandpaper can also be used, but the residue it creates needs to be thoroughly rinsed off before you lubricate the engine and ride it again

If you follow these steps, there’s no reason you can’t keep your engine running for well-beyond the standard 400-500 engine hour life of a typical jet ski.  Keeping your engine happy and in good condition is perhaps the most important step to keeping your jet ski running well for the long haul and preventing and removing corrosion is one of the most essential components to accomplish this.