As the fall season arrives in the northern hemisphere, many boaters find themselves facing the inevitable task of winterizing their boats. After making the most of the remaining boating days, it's time to prepare the boat for the winter months ahead. Winterizing involves safeguarding the boat from freeze damage, weathering, and the growth of mold and mildew. The extent of winterization required may vary depending on the local weather conditions, but there are essential steps that every boat owner must consider. From thorough cleaning to draining all systems and preparing the engine, there are key aspects to getting a boat ready for winter, as we discussed in a previous guide.
Now, let's delve into the specific steps involved in winterizing a boat engine.
Why Winterizing Your Boat Motor is Essential
Living in an area where the temperature drops below freezing means that you need to winterize your boat motor. This is crucial to protect the most expensive part of your boat from the damaging effects of water during the colder winter months. When water is left in certain parts of the motor and the temperature drops below 32 degrees fahrenheit, it can freeze and expand, creating pressure on those parts. This freezing and thawing action can occur multiple times over the winter, making the problem even worse.
It's not just freezing water that causes damage, but water in general, as well as high humidity levels in winter months. Winterizing your boat might seem like a lot of work at first, but it isn't complicated and it will keep your motor healthier for a longer period of time.
The Three Main Steps for Winterizing All Boat Motors
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Change the Oil and Oil Filter: Impurities and moisture in the motor’s oil can cause damage over the winter. Change the oil and filter, then run the motor for a few minutes to circulate the new oil throughout all the parts.
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Change the Fuel Filter and Stabilize the Fuel: Over winter, the ethanol in gasoline can absorb water and cause it to separate from the gas, leading to corrosion in the fuel tank. To prevent this, fill the fuel tank almost to the top and add a stabilizer which prevents phase separation.
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Drain the Water from the Engine and/or Use Antifreeze: This step is crucial and varies depending on whether you have an inboard or outboard motor.
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Essential Steps for Preparing an Outboard Motor for Winter
Winterizing your outboard motor is crucial to ensure its longevity and proper functioning when the warmer seasons return. Here are the essential steps you need to take to winterize your outboard motor:
Flushing the Motor
Begin by thoroughly flushing the motor with fresh water according to the manufacturer’s instructions. This can be done by running the engine in clean, fresh water or by attaching a hose to flush the engine without turning it on.
Replacing Engine Oil and Filter
Next, drain and replace the engine oil and filter. For four-stroke engines, it is essential to change the powerhead oil. However, if you have a two-stroke engine, you can skip this step as its lubrication comes from the oil in the fuel, and there is no powerhead oil. Running the engine before changing the oil helps ensure that any contaminants are picked up.
Changing Gear Case Oil
Change the oil in the gear case and replace the seals on the drain plugs to maintain the proper functioning of the gear case.
Engine Fogging
It is important to fog the engine to apply a protective coating of oil on its internal parts. Follow the manufacturer’s recommended procedure for fogging, as different engines may have different requirements. This can be done by running the engine with a special fuel additive or by spraying fogging oil directly into the engine.
Treating the Fuel
Adding a stabilizer to the fuel helps prevent fuel deterioration and ensures that the engine starts smoothly when it is used again.
Engine Cover and Storage
If possible, cover the engine to provide additional protection against the elements. Additionally, consider storing the engine in a dry place if it is a small outboard. For larger engines, store it in the running position (tilted down) to prevent water ingress.
Essential Steps for Winterizing an Inboard Motor
When it comes to winterizing an inboard motor, the approach differs from that of an outboard motor. While outboard motors are attached to the stern of the boat and can even be easily removed, inboard motors are located in the hull of the boat, either in the bilge or in their own separate engine room.
Our focus here is on the DIY winterizing of inboard engines, as many larger boats leave this task to the professionals.
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Flush the Motor with Fresh Water: Thoroughly flush the engine according to the manufacturer’s instructions, usually using a regular garden hose.
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Drain and Replace the Engine Oil and Filter: Flush out and change the oil according to the manufacturer’s instructions. Run the engine first to ensure any contaminants are picked up in the oil.
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Remove the Spark Plugs: This is a good time to change them if required as part of your ongoing maintenance schedule, and fog the inside of the cylinders.
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Add Antifreeze: Fill the cooling system with a good quality antifreeze. Make sure you have enough antifreeze before starting (at least two gallons but even as much as five). Follow the manufacturer’s recommended procedures for your specific cooling system.
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Add Fogging Lubricants: Apply fogging to the engine to put a protective coating of oil on its internal parts. Follow the manufacturer’s recommended procedure for your specific engine.
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Cover the Boat: Consider the different options for covering your boat throughout the winter months, such as plastic tarps, canvas tarps, fitted covers, and shrink wrapping.
Tips for Winterizing Your Boat Motor
Understanding the Difference Between Coolant and Antifreeze
It's a common misconception that coolant and antifreeze are the same, but they serve different purposes. Engine coolant is responsible for regulating the engine's temperature, while antifreeze is used to prevent freeze damage. In most cases, a mixture of ethylene glycol and water functions as both a coolant and antifreeze in the engine. However, it's important to note that ethylene glycol is toxic, so for other systems of the boat, such as the freshwater system, propylene glycol should be used as an antifreeze instead.
Winterizing an Outboard Engine
If your outboard engine is stored properly in the full down position, you may not need to add antifreeze. Outboards are designed to completely drain when tilted down, so running antifreeze through the engine would simply result in it draining back out.
Implementing Eco-Friendly Practices for Winterization
While winterizing products are known to have negative effects on the environment, there are ways to minimize these impacts. Opting for propylene glycol antifreeze is a more environmentally friendly choice, as it is less harmful to marine life. It's also important to catch antifreeze in a bucket during flushing and dispose of it safely, rather than letting it discharge overboard. Additionally, using absorbent pads under the work area and working with smaller containers of hazardous fluids can help prevent spills. When wrapping your boat for winter storage, be sure to recycle the shrink wrap through designated programs at local marinas, but remember to remove straps, zippers, and vents before recycling.