In a perfect world, we would be able to take our boats out on the water with complete peace of mind and not worry about maintenance and flushing our outboard motors every time. But realistically, there are lots of things in the water that can harm an outboard. These include sand, gravel, and weeds if the outboard is not taken care of and serviced regularly.
Luckily, as your expert on boat servicing in Brisbane and the Logan City and Redland area, we can help with the right advice and service.

Let’s go over the most common damages caused by sand, gravel, and weeds so that we all know why we should avoid them, what problems to look for if there is any damage, and how to avoid getting these things in the motor in the first place!


Sand, along with mud and silt depending on the specific makeup of the environment, can do some real damage to the engine if dredged up regularly. These particles can very easily make their way into a motor’s cooling galleries which may quickly lead to the motor overheating. Even though this may not happen with one single dredging event, it always pays to keep an eye out for signs of overheating and flush after every use.

It is important to be mindful of sand and fine particles whenever we offload our vessels from their trailers into shallow waters if we go through shallow waters, or if the unfortunate happens and we run aground. When flushing out an outboard motor after use, it is essential to ensure that no sand build-up in the motor’s cooling system could lead to blockages. This is why it is important to follow the motor’s flushing instructions to the letter and regularly bring it in for boat servicing in Brisbane.


Like sand, gravel is another pro at making its way into an outboard’s cooling galleries and blocking them. This leads to the motor overheating and possibly cooking. When our vessel encounters gravel though, the gravel can also lead to impact damage to both the propeller and gearbox. In some instances, a damaged prop will just lose efficiency, resulting in a loss of speed along with an increase in fuel consumption. However, it can lead to additional damage to the rest of the motor, especially the lower unit of the outboard.

Damage to the gearbox can result in shifting issues, overheating, and in the worst case, the motor not working at all. Signs of damage include finding water in the gear lube, clunking sounds and the inability to shift between gears.


Weeds and other water vegetation can seem harmless enough to those who haven’t had the experience, but they can do some damage. Powering through a patch of seaweed can cause the vegetation to either wrap around the prop or damage the motor. Even worse, it can clog the outboard’s water intake leading to the motor overheating or damage to the impeller and water pump.
Since seaweeds and other aquatic vegetation can be found in both shallow and deep waters, the best way to avoid them is to be cautious in waters that you aren’t familiar with. Either keep away from those areas where you know there is lots of vegetation or take things slowly and look after your outboard.

A lot of the time, sand, gravel, and weeds won’t present immediate issues but if they are left to accumulate and build up in the motor, they could spell disaster and lead to some expensive repairs. This cab be avoided with regular boat servicing in Brisbane.

Why Trust Mike’s Marine

This is why maintenance is so important, and the best people for the job are the certified MERCURY motor mechanics at Mike’s Marine. Our family-owned business has over 80 years of combined experience in the industry, servicing all models with a MERCURY and MERCRUISER-certified workshop in Capalaba, Queensland.

Call us today to meet the best boating specialists in the area and get your outboard serviced today!