Outboard Maintenance: How to Flush Your Engine

Flushing the outboard motor is one of the significant aspects of boat maintenance. However, many boaters overlook this part of boat upkeeping, sometimes leading to substantial repair costs and reduced engine lifespan.
In this post, we will examine the importance of the flushing process in outboard maintenance, various methods, and some expert tips for keeping your boat motor running smoothly.

Why You Should Flush the Outboard

As mentioned earlier, regular flushing is crucial, especially if you operate in saltwater. Saltwater quickly corrodes vital components of the engine. Hence, marine professionals suggest flushing your outboard after every use. It will help minimize the corrosion risk and ensure smooth performance.
The Benefits of Proper Flushing: Removing Dirt, Debris, and Salt for Improved Performance & Durability

What Happens if You Do Not Flush the Engine Regularly

Ignoring to flush your outboard engine can lead to severe consequences. The salt in the water can block the flow of the cooling system in the boat motor and corrode the parts from inside. The salt build-up increases the risk of corrosion, downgrades performance, and reduces longevity.

When the salt dries, it becomes hard, and even freshwater flushing might not be helpful in cleaning the motor. It can also restrict the water flow, which may result in engine overheating and damage. If the situation gets worse, you might need to immediately repair or purchase a new engine from an outboard dealer in BC.

Boat Motor Flushing Methods

We will look at some of the most common methods to flush your Mercury outboard.

Freshwater Flushing

One of the most common and user-friendly methods to clean the outboard after every trip is freshwater flushing. Whether you choose to use flushing muffs or a flushing port, the process is straightforward and can be easily done by any boat owner.

1. Using Flushing Muffs

Flushing muffs look similar to earmuffs. There are usually three types of muffs available for the process: rectangular, round, and nose cone. Consult your nearby marine engineer to select the right one, especially if you do it for the first time.

• Place the muffs over the water intake ports on the outboard gearcase.
• Attach a garden hose to the muffs and turn on the water supply.
• Start the engine and keep it in an ideal state in neutral for at least 5-10 minutes.
• The water should flow out from the tell-tale, indicating the motor is pumping the water.
• If the tell-tale doesn’t start soon or the water is not coming out, block any holes from where the water is coming out. If there is only leakage around the muffs, push them to make the seal tighter.
• Don’t leave the boat unattended while flushing. If you encounter any issues, turn the motor off immediately.
• Once the flushing is done, turn off the motor and then the water supply.
• Some engines need propellers to be removed before flushing. So check the manual before starting the process.

2. Using Flushing Port

This is one of the easiest and most common methods. If your engine has a flushing port attachment (most modern Mercury outboards have an in-built flush connection), you can do this process efficiently.
Remember, when you flush the motor using the port, you do not need to run the motor. Also, if the outboard has multiple ports, use only one at a time to complete the process. The additional ports are provided for your convenience, as you can access them from inside or outside the boat.

• Trim down the engine.
• Look for the flushing port cap and remove it.
• Attach the flushing attachment provided by the dealer (Mercury engines come with integral flushing port(s))
• Connect the garden hose with the attachment. Turn on the water.
• Do not start the outboard. If you do, it might overheat the impeller and damage or melt it.
• Run the water for at least 5-10 minutes.
• As the engine is not running, you can do your activities around the vessel and turn off the water once the process is completed.
• Remove the garden hose and flushing attachment and replace the flushing port cap.
• Keep the engine down for some time to drain the water.
• To make the cooling system work normally, you should replace the flushing port cap with a complete seal.

3. Using Flushing Bags or Buckets

A large, robust, water-filled bag, working like a water tank, is a flushing bag or bucket. It can be made of soft plastic, vinyl or canvas. In most cases, flushing bags require the boat propellers to be removed. So, it’s better to contact your nearby marine engineer and take the guidance or help.

• Keep the vessel on the boat trailer with an arrangement such as tilting the engine.
• Fit the flushing bag around the motor gearcase and secure it in place.
• Fill the bag with fresh water using a garden hose. Ensure the water intake ports are covered.
• Start the engine and run it ideal in neutral.
• The outboard will start pumping water from the reservoir, and the hose will maintain the water level.
• Do not leave the motor unattended while the flushing is on. Keep an eye on the tell-tale from where the water should be flowing.
• Allow the outboard engine to run in this state for at least 5-10 minutes. This process will ensure the water circulates through the cooling system.
• Once done, turn off the engine and then the garden hose. Remove the flushing bag.

Note: Different outboard brands might have specific flushing processes. Hence, referring to the owner’s manual is essential before proceeding. If you have any questions, contact a marine professional from a trusted boat repair service in BC.

Advanced Flushing Options

Sometimes, when there is too much salt build-up on the engine parts or the corrosion is already in effect, you need professional help from an experienced marine service team. They will advise and use a commercial flushing solution to remove the salt deposits. Their team will also run the proper outboard cleaning process and replace the components if required, ensuring the engine is ready to take on any water challenges on the West Coast.
Ready to Optimize Your Outboard’s Performance? Follow These Expert Tips on Flushing
1. Flush the engine after every trip, mainly when used in saltwater conditions, even if it is just a short run.
2. Inspect the engine’s cooling system for leaks or blockages before and after every boating trip.
3. Never start the engine without a water supply.
4. Keep the engine ideal in neutral only. Do not run it in gear in any circumstances.
5. The flushing process should be run for a minimum of five minutes. After flushing, drain all the freshwater from the engine.

Conclusion

Outboard flushing is an easy but crucial part of boat maintenance. Following the process correctly can significantly impact the boat’s performance and durability. Different manufacturers may have different recommendations for boat motor flushing. Hence, it is not possible to cover every aspect here in the blog. We have covered the generic process, which you can apply to almost all types of outboards.
To learn more or for any service-related query for your vessel or engine, contact us. As a reputed and experienced British Columbia boat dealer, we are here to assist you with all types of boating needs and make your on-water experience enjoyable.