Algae Bloom

Three tips to maintain Yamaha Outboard Parts from Algae Bloom

Along with concerns for humans, water and beaches, the bloom has affected boat maintenance and requires diligence from boaters wishing to protect their vessel and its Yamaha outboard parts. The large blue-greenalgae bloom that has erupted in south Florida recently has caused concern for the people’s health and the environment as it fills the water and coats beaches in foul-smelling slime.

Origins of the bloom
The algae bloom currently affects Lee, Palm Beach, St. Lucie and Martin Counties and may affect others as time passes. The cause of the bloom is the polluted waters from Lake Okeechobee as the Army Corps of Engineers releases discharges through locks to prevent flooding of nearby towns. The aging dike system can’t handle a large amount of runoff and rain flowing into the lake and discharging the water through east and west locks seemed the only way to prevent flooding. Unfortunately, the water from the lake contains agricultural pollutants runoff containing inorganic fertilizers and manure and the discharge flows into downstream rivers and lagoons before eventually reaching the ocean.


"The combination of pollution, freshwater, and saltwater causes huge phosphorescent algae plumes and the current bloom makes the water unsafe for humans and animal life. The warm temperatures, large amounts of sunlight and calmer waters of the southern Florida waterfront communities have made the algae bloom worse.”

Impact on outboard

As you deal with the cleanup of the algae bloom, you take special care to wash and wax your contender boat and outboard but you may overlook the outboard’s cooling system and this can be detrimental. During normal use, the water pump pulls in sand, silt and mud that then flow through the engine, but during the algae bloom it could have pulled in additional toxins that can harm your Yamaha outboard parts if you don’t flush the system properly. Marine growth behind inlet screens and debris accumulation in outboard cooling passages are common occurrences but algae blooms are not and left untreated, all of these factors can lead to insufficient cooling and engine damage.

Credit: Hans Paerl, University of North Carolina

Protecting your Yamaha outboard parts through all marine extremes is essential to protecting your boating investment.

Fresh water flushing

In normal conditions, the outboard requires flushing following every occasion you use it in dirty water or salt water. Flushing the system with clean freshwater dislodges silt, sand and mud and forces them out of the cooling system passages while also removing salt buildup that may lead to engine block corrosion and poor cooling. Freshwater flushing protects your contender boat and Yamaha outboard parts and can extend their lifetime, especially in light of the recent algae bloom.

There are three main tips for flushing your outboard parts:

#1 Flush bag –

This method uses a collapsible bag that’s sturdy, fits below the lower outboard unit and fills with water. The flush bag submerges the gear case and once the bag is full, you run the engine, which allows the motor to pull in the cooling water through inlet screens and send it out via the propeller. This method works best on outboards with more than one inlet attached to boats that are moored or on a trailer.

#2 Flush muff –

This method works for single inlet lower unit outboards and uses a garden hose and rubber cups (muffs) that you fit on the water inlet of the gear case. With the garden hose attached to the hose fitting on one of the cups and the water running, you run the engine to flush the system. To do this safely your boat should be on a boat lift or trailer and completely out of the water. Always turn the freshwater on prior to running the engine to avoid overheating damage to your Yamaha outboard parts and system and never rev the engine as there’s insufficient water to cool the system at high RPMs.

#3 Built-in device –

This device is a hose fitting usually found near the lower rear cowling of the outboard. To flush with this system, you can’t run the engine. The gear case should be out of the water but the boat can be on a lift or in the water while flushing.

Whatever method you choose to flush your system and protect your Yamaha outboard parts of the damaging effects of the algae bloom always make sure the inlet screen on the lower unit look clean and clear following flushing. Even without the algae bloom problems, freshwater flushing extends the outboard’s lifespan when you boat in saltwater.

Contender Boat exterior

Removing the algae from your boat exterior requires cleaning agents specifically designed for the vessel’s material. The best way to prevent staining and remove algae after you’ve been out on the water is to wash the hull immediately with fresh water. If you have a boat lift or trailer for your boat, get your vessel up out of the water and rinse it thoroughly. For tough algae stains, consult an expert to learn the best and safest methods for restoring your boat’s appearance without damaging the material or finish.


Along with keeping your boat looking great, running properly and protecting your parts with freshwater flushing, you need to address additional issues the algae bloom created for waterfront residents. The danger, appearance and strong smell of the algae bloom may have forced you to stay inside, visit friends or relatives in other areas and even stay in hotels until the bloom dissipates. If you’re someone who spends most of your life out on the water, this is especially discouraging.

Cleaning off docks and other waterside surfaces is essential for safety as the algae slime can cause slips and falls. Manually washing the algae off docks, steps and ladders with water or other environmentally safe cleaner is better for the marine life than using bleach. Unfortunately, bleach has proven the most effective in removing algae and preventing regrowth so if you decide to use this agent, you should dilute it to minimize harmful effects.

Removing the harmful algae with another agent that harms the environment by being toxic to fish and shellfish is counterproductive in the already over-stressed Florida shorelines.

Boat and dock ropes

The sight of green, slimy algae on your boat ropes and ties may make you want to wash or soak them in bleach, but this is unnecessary and often harmful to synthetic ropes. Although some staining may remain on the ropes, rinsing them with fresh water is the best way to keep them clean as algae and mildew don’t actually weaken synthetic ropes. For especially stubborn algae stains, soaking the ropes in hot water and an appropriate amount of mild detergent for a few hours does the trick. Agitating the ropes by hand following the soak and scrubbing any remaining spots with a brush can help remove slippery residue.

Follow up by washing any ropes or ties in a pillowcase in a clothes washer but continue to avoid harsh detergents or bleach. Bleach can roughen line texture, make it stiffer and remove lubricants, diminishing its usefulness in securing your contender boat. Allow washed ropes and ties to dry completely in the sun before using.

Eventually, the algae bloom issues will have a resolution, but until that time, it’s vital to protect your contender boat’s Yamaha outboard parts, motor, dock, and property