How to Maintain Your Boat Engine

Keeping your boat engine well maintained will inevitably keep it functioning for longer. Follow these simple steps before and after each trip to keep breakdowns at bay.

With over 20,000 miles of coastline and 2,000 miles of canals and rivers, the UK offers plenty of choice to intrepid boaters looking for new waterways to explore. But when you’re boating, the last thing you want is for your pleasant day out on the water to turn into a crisis when your engine breaks down.

Fortunately, you don’t have to be a mechanic to keep your boat engine in good repair. Here are some before-and-after maintenance tips to keep your motor running smoothly:

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After Every Outing

Wash your boat – If you’re boating in saltwater, the best way to preserve your boat over the long term is to give it a quick wash after every trip. Make sure to wash and rinse your motor blades as well—saltwater corrodes metal and can damage your motor if left untended.

Flush out the engine – Whether you’re sailing in freshwater or saltwater, flushing your engine after each outing is a must. Most outward motors require you to use flush muffs, which are inexpensive and easy to use:

1. Attach one end of the flush muff to your garden hose. The other end fits over your water intake.

2. Cover any other water intakes not covered by the fluff muff.

3. Turn the water on.

4. Start up the engine to flush your system. Remember to keep the motor out of gear.

Check the water pump flow – Carefully check the force of the water exiting your motor during flushing. If the outflow tube is obstructed, as indicated by weak water flow, turn your engine off and carefully try to remove the debris with wire. If water flow is still weak, you may need to replace your water pump impeller (this should be replaced every two years).

Clean your boat, Towergate

Apply anti-corrosive grease – Use an anti-corrosive lubricant like WD-40 to grease all pivots, valves, throttle cables, and other moving parts.

Cover your motor – Cover your motor with a canvas or plastic cowling while not in use.

Winterise Your Engine

Finally, when it’s time to retire your boat for the season, you’ll want to make sure that you thoroughly clean your engine, grease engine steering and control parts, change your engine oil, and replace filters. Depending on your type of engine, you should also:

  • Raw water cooled engine: completely drain the engine and then close the intake.

  • Fresh water cooled engine: drain the coolant and fill with half water and half antifreeze.

Note that while gas engine fuel tanks and lines should be completely drained and the fuel lines disconnected before winter, you may want to completely fill diesel engines before storage to reduce condensation build up in the tank.

Looking for more tips before you hit the open seas? Check out our Pre-Season Sailing Checklist.

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