Flushing Out Your Yamaha Boat Engine: Step-By-Step Guide

Flushing your Yamaha outboard engine is an essential part of boat maintenance. It should be done after every use, especially if the boat has been in salt or dirty water, to prevent a build-up of salt and other contaminants like sand, silt, and mud. This build-up can cause poor cooling and corrosion, which can lead to engine damage. There are three methods to flush a Yamaha outboard engine: using the freshwater flushing attachment built into the outboard, flush bags, or flush muffs. The flushing procedure involves positioning the engine, accessing the freshwater hookup, using a salt-away nozzle, starting the flush, switching to salt-away, and then disconnecting and securing the engine.

Gather your materials: engine muffs, a salt-away nozzle, and a salt-away product

To flush out a Yamaha boat engine, you will need to gather the following materials: engine muffs, a salt-away nozzle, and a salt-away product.

The engine muffs, or "ear muffs" as they are sometimes called, are an essential component of the flushing process. They are rubber cups that fit over the water inlet on the gearcase of the engine. It is important to ensure that the muffs are securely in place before turning on the water supply, as this will prevent water from entering the engine through the inlet.

The salt-away nozzle and salt-away product are also crucial for effective flushing. The salt-away nozzle is designed to connect to the water hookup on the engine, allowing you to introduce the salt-away product into the system. This product is specifically formulated to dissolve salt and remove buildup, which is essential for maintaining the performance and longevity of your Yamaha boat engine, especially if you often operate it in saltwater environments.

By gathering these materials—engine muffs, a salt-away nozzle, and a salt-away product—you will have the necessary tools to properly flush your Yamaha boat engine and ensure its optimal performance.

Position your engine: tilt your motor as far down as possible

To flush out a Yamaha boat engine, it is important to properly position your engine. This involves tilting the motor as far down as possible. However, it is important to note that the motor doesn't have to be all the way down if that position is not achievable.

Tilt the motor as far down as possible to ensure that the flushing process is thorough and effective. By tilting the motor, you allow the freshwater and Salt-Away product to flow through the engine and flush out any contaminants or salt buildup. This helps prevent damage to the engine's cooling system and promotes long-term engine health.

The positioning of the engine is a crucial step in the flushing process, as it ensures that the engine is ready to be flushed and that the flushing liquid can reach all the necessary areas. Once the engine is tilted, you can proceed to the next step, which is accessing the freshwater hookup.

It is important to follow the correct procedure when flushing a Yamaha boat engine, as it ensures that the engine is properly maintained and helps extend its lifespan. By tilting the motor as far down as possible, you can effectively flush the engine and prevent any buildup or corrosion that could potentially cause damage over time.

Overall, positioning the engine by tilting the motor as far down as possible is a crucial step in the process of flushing a Yamaha boat engine. It ensures that the engine is ready for flushing and allows for a thorough and effective flushing process.

Access your freshwater hookup: locate the hookup on the engine's side and thread the freshwater supply hose into it

To flush out a Yamaha boat engine, you will need to access the freshwater hookup on the engine's side. This is an essential step for the proper maintenance and longevity of your outboard engine. Here is a detailed, step-by-step guide on how to do this:

Locate the Freshwater Hookup:

The freshwater hookup is typically located on the side of the engine. It is usually positioned near the lower rear cowling of the engine. This hookup serves as the entry point for freshwater to flow into the engine's cooling system.

Thread the Freshwater Supply Hose:

Once you have located the freshwater hookup, it's time to thread the freshwater supply hose into it. Ensure that the hose is securely connected to the hookup. This hose will supply the freshwater needed to flush out any contaminants and salt buildup from the engine.

Understand the Importance of Freshwater Flushing:

Freshwater flushing plays a crucial role in maintaining your Yamaha boat engine. Over time, the water pump can ingest mud, sand, and silt during normal use, which then passes through the engine. Additionally, marine growth can obstruct the flow of water to the engine by accumulating behind the inlet screens. By performing freshwater flushing, you can dislodge and remove these contaminants, preventing damage to the water pump and improving the engine's cooling efficiency.

Choose the Appropriate Flushing Method:

There are three common methods for flushing a Yamaha outboard engine: using the freshwater flushing attachment, flush bags, or flush muffs. The flushing attachment method is often the easiest and quickest, especially for boats moored in the water. The flush bag method is ideal for motors with multiple inlets per side, as it allows for comprehensive flushing. Meanwhile, the flush muff method is recommended for models with single inlet lower units, and it is typically done with the boat on a trailer or lift.

Follow Safety Precautions:

It is important to remember never to run the engine without cooling water. Always turn on the freshwater supply before starting the engine and turn it off after stopping. Running the engine without adequate cooling water can lead to expensive overheating damage. Additionally, avoid revving the engine while using flush muffs, as there may not be enough water flow or pressure to cool the engine at high RPMs.

Use a salt-away nozzle: fill it up and thread the hose and then the nozzle into the water hookup

Flushing your Yamaha outboard engine is essential for its proper maintenance and longevity. Here's a step-by-step guide on how to do it using a salt-away nozzle:

Step 1: Gather Your Materials

You will need a few essential items for this process: engine muffs, a salt-away nozzle, and a salt-away product. The salt-away product is crucial as it effectively dissolves salt, is biodegradable, and non-toxic, making it safe to use on the water.

Step 2: Position Your Engine

Properly position your engine by tilting the motor as far down as possible. It doesn't have to be all the way down if that position is not achievable.

Step 3: Access Your Freshwater Hookup

Locate the freshwater hookup on the side of the engine. This is where you'll connect the water supply for flushing.

Step 4: Use a Salt-Away Nozzle – Filling and Threading

Now, it's time to use the Salt-Away nozzle. Fill the nozzle with the salt-away product. Make sure it's filled to the top. Then, take the hose and thread it into the nozzle. After that, you'll need to connect the nozzle to the water hookup, which is linked to the flushing hookup.

Step 5: Start Flushing

Turn on the freshwater supply and let it run for a few minutes. You'll start seeing water coming out from various areas of the engine, such as the prop hub, the backside of the gear case, and the pedo tube.

Step 6: Switch to Salt-Away

After approximately five minutes of flushing with freshwater, it's time to switch to Salt-Away. Move the connector to the Salt-Away position and observe the foam being released from different parts of the engine. Let it remain in this position for about 10 minutes.

Step 7: Disconnect and Secure

Finally, disconnect the flushing hookup and ensure it's securely threaded in the correct position. This step is crucial to prevent any issues while running your engine on the water, as a loose connection could lead to overheating.

Start flushing: turn on the freshwater supply and let it run for a few minutes

Now it's time to start flushing your Yamaha boat engine. Turn on the freshwater supply and let it run for a few minutes. You will begin to see water coming out from different areas of the engine, such as the prop hub, the backside of the gear case, and the pedo tube.

This process is an essential component of proper outboard motor maintenance. Flushing your engine will help to dislodge contaminants like sand, silt, and mud, as well as removing salt buildup. This will prevent poor cooling and corrosion of the engine block and midsection, which can lead to overheating and engine damage over time.

While flushing, keep an eye out for water exiting the back of the gear case. Make sure that the rubber cups are in place over the inlets. You should also check that the water flow is sufficient—if not, you can increase it.

Let the freshwater run through the engine for around 5 minutes before moving on to the next step.

Frequently asked questions