How to Prepare to Lay-Up Your Boat

October 11, 2016 - 9:00 AM by Samantha Pudney


Thinking about a lay-up period for your boat for the season? When a boat is laid up or taken off the water for an extended period of time, a few steps of preparation can do a world of good to extend the life of your marine engine.

Corrosion and frost are your worst enemies during this vulnerable time, so all systems should be attended to. Follow your engine manufacturer’s recommendations closely, as there are a number of differences that can occur between individual makes.

Cooling System

Start by checking the hoses, fittings and hose clips in your cooling system. Keep an eye out for signs of a leak, deterioration or rust, then replace each component as necessary. This also includes water pump drive belts

Heat Exchanger

Your indirect systems will need to be drained and flushed with clean water, then refilled with a mixture of clean water (preferable de-ionised) and antifreeze, including a corrosion inhibitor. While you’re flushing the engine, take time to drain the heat exchanger, then run the engine to working temperature to provide circulation.

If your marine engine has been running hot, remove and clean the heat exchanger tubes. Even at a normal running temperature, this is best practice for your engine.

We would suggest removing the water pump drive belt once the engine has been fully prepared for long term storage

All Raw Water Systems

Flush your raw water systems with fresh water by running the engine with the inlet pipe drawing from a bucket. Keep the bucket of water filled until at least 20 litres has been successfully flushed through.

Then, mix the correct amount of antifreeze for the expected temperature with the water. Let your engine draw the mixture into the cooling system until the bucket is empty. At this point, stop the engine. If you don’t have antifreeze, a soluble oil and water will also work to inhibit corrosion.

Remove the raw water pump impeller. We would suggest removing the seawater pump drive belt once the engine has been fully prepared for long term storage.

Boats in Storage by Michael Pereckas, January 6, 2007. CC-BY 2.0

Boats in Storage by Michael Pereckas, January 6, 2007. CC-BY 2.0

Lubricating System

Change your lubricating oil filter and pump out the lubricating oil from the sump or drain through the drain plug to replace with fresh oil. If you are going to lay-up your boat for an extended period of time, then use an inhibiting oil. Remember – this must be replaced when the engine is recommissioned.

Air System

Often, the paper or foam element is dirty in one area only. Clean the air intake element to inspect this component. If in doubt as to its quality, then always replace the part. A restriction in air intake will cause unwanted combustion problems down the track.

What most avid boaters know (but can forget) is that an engine needs far more air than it needs fuel. Lastly, tape over the inlet to stop the air from circulating inside the chamber.

Fuel System

Minimise condensation by filling up to keep the air in the tank at an absolute minimum. At least once in every five years you should pump out the bottom layer of fuel, water and debris. Then, dispose of it responsibly into a container.

Keep the fuel tank clean, if the arrangement enables it, by draining the sump at the bottom of the fuel tank. This is worth consideration if you will need to install new tanks for any reason down the track. Lastly, don’t forget to check externally for rust and leaks, particularly focusing on the underneath of the tank if it is metal.


Rectify any leaks in the piping and remove the injectors, before directing a couple of squirts of upper cylinder or lay-up lubricant into the injector pockets.

Before reinstalling the injectors, slowly turn the engine one revolution by hand to distribute the lubricant. Do not under any circumstance use the starter motor while carrying out this task, in case there is too much lubricant in the cylinder. This could do substantial damage to your engine.

For engines that are unwilling to start, try having the injectors serviced before you refit them and always replace sealing washers while injectors are refitted.

General Maintenance

Alongside the specific system maintenance that you will need to carry out are the everyday checks to ensure the overall quality of your boat. Clean the engine to check that all the nuts and bolts are tight, as well as review your mounting bracket for any cracks.

Avoid air blowing through your engine by plugging the exhaust exit and finally, spray all of the exposed metal areas with water-inhibiting oil, except the alternator.

Outdrives & Saildrives

Drain and replace the lubricating oil in your outdrive and saildrives. Sacrificial anodes will also need to be checked – it’s crucial that these are replaced if they are below 50 percent of their original mass.

Last but not least, check all of the seals, hoses and bellows to replace any damage and extend the life of your boat – ready for the next time you use it!

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