PartsVu.com is happy to offer a broad selection of certified Yamalube corrosion inhibitors and lubricants. These specially formulated rust protectants and lubricants are designed to keep your Yamaha outboard engine free of corrosion, so it will remain in peak condition for years to come. Our Yamalube corrosion inhibitors and lubricants come in a variety of sizes and in multipacks, so you can save money by buying in bulk.
We also regularly release new, helpful resources like:
Yamalube Corrosion Inhibitors and Lubricants FAQs
Why is Yamaha outboard corrosion prevention important?
Yamaha corrosion prevention is a top priority for the longevity of your engine and time is of the essence.
Regardless of where you boat, corrosion attacks both the inside and the outside of your Yamaha outboard motor –every day, all the time. Some forms you can see, some you can’t, and it can take only a short time for the damage to begin. Even those boating in freshwater has corrosion-mitigation duties to attend to. Even rainwater can have corrosive effects that can be damaging to your outboard. So it’s vital to be diligent in your anti-corrosion defense.
PartsVu can help provide the right products to help prevent some forms of outboard corrosion, but their regular and diligent use is strictly up to you.
Outboard corrosion can happen pretty much anywhere on or in your outboard: inside, in your fuel system, or in the internal cooling water passages, and on the outside, in various electrical connections and exposed metal components. But don’t worry, you have a lot of allies on your side, and we’re here to help by teaching you where to look and what to look for.
It’s a good practice to set up a regular schedule and stick to it. There are quick and simple things you should do after every use if you boat in saltwater, and periodically if freshwater is your game. These include visual inspections you should do every time. Yamashield is an excellent rust and corrosion protectant and if you are unsure about what to do when PartsVu can help.
What is “Dry Corrosion”?
Dry corrosion occurs in areas on your Yamaha outboard engine not in direct contact with water—exhaust systems, for example. The outside of most Yamaha exhaust system components is cooled by raw water to prevent overheating. When today’s ethanol-enhanced fuel is burned, it creates by-products known as sulfate salts. These salts are highly corrosive, especially when exposed to very hot temperatures. If the marine outboard’s cooling water passages are not kept clean by regular flushing (the exhaust area in this example), hot spots can form on the interior of the exhaust components, concentrating the sulfate salts’ corrosive effects. In effect, it’s corrosion from the inside out. That’s why flushing your engine with fresh, clean water for 15 minutes after each trip is a vital part of preventing even dry corrosion. It helps the cooling system run at maximum efficiency by keeping the cooling water passages clean and clear, which helps minimize the heat inside the engine, making it less susceptible to dry corrosion.
Why is it important to flush my Yamaha outboard if I’m a freshwater boater?
Your Yamaha outboard is raw-water cooled, meaning it uses the water it’s operating on as cooling water. All water, fresh or salt, contains contaminants that will eventually build up in the cooling passages over time. Additionally, saltwater is naturally corrosive and any remaining in those cooling water passages after use is left there to do its worst, unabated. Saltwater can also experience crystallization when exposed to heat above 170 degrees, which causes deposits to form and potentially restrict cooling water passages. For these reasons, it’s a must that you flush your engine thoroughly with fresh, clean water after every use.
What are the three types of outboard engine corrosion?
When metals are exposed in the presence of water, whether fresh, brackish or salt, marine corrosion is inevitable. From the moment they are manufactured, nearly all metals are trying to return to the original form in which they existed when we dug them out of the ground.
The three types of corrosion boaters typically work to manage are:
- Simple electrochemical corrosion
- Galvanic corrosion
- Electrolytic/stray current corrosion
All three types of marine corrosion are the result of an electrochemical process, the difference is how fast the corrosion occurs. The process speeds up when multiple metals are involved (galvanic corrosion) and faster still when unwanted electrical currents are applied (stray current corrosion). While the result of any of these types of corrosion is pretty much the same – exposed metal damage – there can be many reasons why the corrosion occurred in the first place. The challenge we face is identifying the type of corrosion and finding its true cause to minimize future corrosion.
How Do I Go About Freshwater Flushing of My Yamaha Outboard?
Use the built-in flush attachment. This is a great procedure to follow, especially if you can’t remove your boat from the water, or if your outboard has dual water inlets and you don’t have the special adapter. Simply connect a garden hose to the inlet side of your non-running outboard’s built-in flush attachment, turn the spigot on full blast, and let the hose’s water pressure do the work. Let the water run for 15 minutes to ensure it fully circulates through the entire cooling system several times. If your boat’s out of the water, like on a trailer or a lift, the freshwater will also trickle down and adequately clean the water pump and the lower unit’s cooling water passages.
The flush muff method. This is the most common and often-used freshwater flushing method. Simply connect a garden hose to clean fresh water on one end and a Yamaha Outboard Engine and Motor Flusher attachment, which slides around the Yamaha lower unit to provide water to both sides of the raw water inlet, to the other end. Turn on the water until you see water squirting out the sides of the flush muff, then start your outboard in neutral. Set the outboard to no more than a fast idle (900-RPM max) and allow to run for 15 minutes in neutral. Increase hose water pressure enough to maintain a bit of squirting out from under the flush muffs at all times while the outboard is running. This helps ensure it gets fed enough cooling water.
What is galvanic marine corrosion?
Galvanic corrosion typically involves two dissimilar metals, aluminum and stainless steel. These metals are bonded together either by direct contact or by the electrical system and are submerged in an electrolyte – the water the boat is in. The assortment of these elements essentially becomes a big wet cell battery.
What happens in a battery when a connection is made between the positive and negative posts? Electrons flow between the battery’s plates, which are anodes and cathodes. On a boat without any corrosion protection, aluminum, being the most active metal, will become the anode and the stainless steel, a less active metal, will be the cathode. Electrons will flow from the anode to the cathode, resulting in a loss of anode material, visible as corrosion on the aluminum components.
Galvanic corrosion typically appears as paint blisters with a white powdery residue on the exposed metal. Corners and edges of components, such as the leading edge of the lower unit and the sides of the anti-ventilation plate, will usually be the first areas affected. Galvanic corrosion is much more destructive than electrochemical corrosion but can be controlled and minimized when you understand the corrosion process.
Be sure to test for deficiencies and apply sound preventative measures. The best first line of defense is to apply a layer of good paint to insulate the metals from the electrolyte. Another method is to introduce an alternate metal, one more active than aluminum, into the system. A metal that is more active will become a sacrificial anode and will provide protection to both the aluminum and stainless steel components. The trick is installing the right amount of sacrificial anode material to protect all of the aluminum and stainless steel, connected either by direct contact or connection to the boat’s electrical system.
