Winterising

28 Sep 2019

So it’s only the beginning of autumn and we’ve decided to blog about preparing for the winter! Realistically, the new school term has started and lives get busy. The workshop diaries fill up and this essential piece of maintenance can easily be missed, importantly creating problems and big bills at the start of the following season. 

There will be all manner of jobs to make sure your boat doesn’t suffer with the cold weather, for now we will focus on the inboard engine

Fill the tank with fuel. Why do you want the tank filled with fuel over winter? It decreases the chance of getting air into the tank because it brings moisture and, with low temperatures in this period, condensation! If you don’t fill up your tank, you’ll wind up with water inside, which can cause severe problems for your engine.

Add the fuel stabiliser. What does it do? Stabiliser prevents build up while your boat sits for long periods, not only in your fuel lines but in your fuel injectors or carburetors as well.

After your motor is cleaned and prepared as described, the first real winterisation step is applying antifreeze. The second step is spraying fogging oils into the engine. The process should be as follows:

First of all warm the engine. This can be done one of two ways: Run the engine if the boat’s in the water or run the engine with an adaptor and a hose running the water supply.

Adding antifreeze to the engine prevents any water—condensation or otherwise—from freezing. Freezing can be harmful because it means expansion, causing stress and eventually cracks. The last thing you need is to find a milky consistency in your oil and to have to call an engineer. Please avoid ethylene-based antifreeze, as ethylene can release toxins into the water.

You want to follow your boat manufacturer’s specifications to drain the engine block. Once the engine block is drained of coolant, then you add the propylene glycol antifreeze.

A sterndrive is an inboard engine with an outboard drive system. So a sterndrive has to be treated like an inboard engine, but with a few additional steps to protect the lower parts. To drain the lines, leave the sterndrive stored in a down position. Using your fresh water source (hose and faucet), allow your boat’s engine to come to temperature. This allows the thermostat to breathe, letting both the coolant and fuel stabiliser circulate through lines, carburetors and injectors.

After applying the antifreeze to your engine, and while it’s still warm, the next step is to spray fogging oil into the engine. Spraying fogging oils into inboard and sterndrive engines is slightly different than spraying it into outboard engines.

Continue the process by filling a five-gallon bucket with non-toxic antifreeze. Closing the intake seacock, transfer the hose to the bucket. Letting the boat engine idle, keep watch for the bucket's fluid to reach low levels and the exhaust to discharge the antifreeze. Time it for 30 seconds or until the bucket is nearly dry, and then proceed to fog the carburetor. Generously spray the fogging oil. Engines with high horsepower may sputter, low horsepower engines may even stall out—but that’s okay! You should see white smoke and, when the antifreeze bucket is finally dry, turn off the engine and re-secure the hose to the seacock.

Alternatively, you can go around removing each individual spark plug. With spark plugs removed, you can then spray fogging oils directly into the engine’s cylinders.

Some boaters tend to leave this task until their spring inspection. We say do it now while your engine is already warm. Draining and changing the oil is easier when it’s warm. Your engine and transmission oil could be contaminated with dirt and particles, which can harm it during winter if not dealt with properly. Using a continuous water supply, with your boat still in the water or using a standard garden hose, start the engine and monitor the fuel filter for leaks. If a leak is found, turn off the engine and make proper repairs. Check the installed filter once again. Restart the engine. Keep it at an idle RPM and allow it to reach regular temperatures. The trick here is to not over-cool the engine! It’s better to cool it off gradually over time. When using a combination hose and adaptor, don’t run the faucet at full-on blast. Cut the faucet off so it’s a steady flow. You want to make sure to let the engine run for 15 minutes at minimum. This will allow the fuel stabiliser to enter the fuel system. If this proves difficult or you’re in a hurry, at least add an oil stabiliser.

Inspect your exhaust system by dissembling it from the water lift muffler. Look it over for anything suspicious like corrosion and buildup. Make sure the raw water injection hose hasn’t become obstructed in any way. Occasionally hoses and hose clamps can become damaged. Check them over to be sure they’re not cracked, shredded or rusty. If they are, be sure to replace them now before you forget come spring! If you find any openings, seal them up! Cracks and openings allow the build-up of damp air and water condensation. Double-check your air inlet and exhaust outlets. You can simply use tape to secure them.

If all of this feels beyond the scope of the DIY engineer we here at Cambrian Boats will be pleased to offer a quote to prepare your engine for the winter months.

And some last-minute things to mention, just so you don’t forget basic boat winterising steps:

• Take care of the battery. Remove and keep it indoors at home, or leave it installed and hook it up to a trickle charger.
• Consider pests. whether you keep your boat on the lift or in storage, plan accordingly with controls and repellants. 
• Invest in a quality winter boat cover. It may be handy to also invest in a dehumidifier and centre poles. Alternatively there are many condensation absorber products available.
• Invest in theft prevention. Stay vigilant and stop by to check on your boat every once in a while.

This way when you come to enjoy a new season, hopefully, you will find your vessel in good order.