Read all of the latest news from Marlin Environmental.

Top tips for Winterising an inboard engine

Winterising your boat properly at the end of the season saves time and money in the long-run and means you’ll be back out with the fair weather sooner than most.

Whether you’re a sailor or a motorboat owner, the process of Winterisation ensures your engine is kept safe and working properly, before hibernation, reducing the risk of engine damage and preventing the fresh water systems from cracking.

If you enjoy maintaining your own boat, then the following checklist should remind you of just some of the host of tasks that need doing before Winter takes hold. 

If you don't enjoy maintaining your own boat, then just give us a call and we can do it for you!

  • Everyone will say this to you... If your boat hasn’t been serviced already, we do advise you carry out a service on your engine before putting it away for the Winter.
  • Carry out a visual inspection and a general engine clean, ensuring the bilges are completely dry beneath the engine, which prevents corrosion on the engine and mould building up.
  • Most diesel engines use a combination of raw (salt) water and fresh water cooling, so drain the cooling system and refill with strong, fresh antifreeze. Run the engine to circulate the new antifreeze around the system.
  • We recommend removing, inspecting and changing the impeller annually.
  • If your boat is out of the water be sure to check your anodes and replace when needed. We recommend checking them annually, too.
  • Cover your engine with anti-rust paper, which helps prevent corrosion on and in the engine.
  • Empty water tanks and drain down the fresh water system, running antifreeze solution through it - and don’t forget to drain your hot water tank and leave taps open.
  • We always advise keeping batteries warm and dry over winter – where you can also easily top them up every four to six weeks - and ensure they’re fully charged. This keeps them ‘ready for action’ and helps to extend their life. As with cars, batteries may need to be replaced completely, if left uncharged for long periods of time.
  • If removing the batteries is not possible, at least disconnect them from the electrical system and clean and grease the terminals. Make sure you top them up and, as above, keep them regularly charged - full batteries are less likely to freeze in cold temperatures.

This list is certainly not finite, but we hope it provides a guide on some of the main tasks that need carrying out when putting your boat to bed for the Winter.

If this list has put you off, we're here to help!