Edit Article How to Winterize a Boat

How to Winterize a Boat

When the sun sets on another boating season, it is time to get your boat ready for the cold winter months. Taking the necessary steps to winterize your boat will safeguard the vessel and its motor against the elements, so it is ready to use when the warm weather arrives. In order to prepare your boat for winter, you must properly winterize the engine, clean the boat and do any necessary repairs, and store your boat in a manner that will protect it from the elements and preserve your investment. Make sure to follow all steps.

Winterizing Your Engine

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    Flush the engine with fresh water. This process will flush salt, dirt, and other contaminants out of your engine in order to prevent blockages and corrosion. Depending on what kind of motor you have, there are a variety of ways to perform a flush.[1]

    • For older outboard motors, get a pair of boat engine “ear muffs” and attach them to the water intakes on your engine. Attach a water hose to the opening on the ear muffs, turn on the water, and let the engine run in neutral until the water runs out clean.
    • Some newer outboard motors have built-in water hose attachments and a flushing system that can be used without running the engine. If you have this type of motor, you can attach a hose directly to the motor and let the water run for about 10 minutes. Check your owner’s manual, if you have one, for the correct flushing procedure.
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    Stabilize your fuel. Unstabilized fuel can degrade during the winter, causing gummy buildups that can clog up your engine supply lines. Fill your gas tank with fuel to about 95% of your tank’s capacity. [2] Add a gasoline stabilizer, like Pennzoil Fuel Stabilizer, PRI-G, or Stabil. Follow the directions on the stabilizer packaging to determine the appropriate amount to add. Run your engine for 10-20 minutes after adding the stabilizer in order to distribute the stabilized fuel.[3]

    • Alternatively, you can drain your gas tank and supply lines completely and leave your tank empty over the winter.[4]
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    Fog the engine cylinders and carburetor intakes. Coating the inside of your engine with fogging oil will help prevent corrosion. Check your owner’s manual or engine manufacturer’s instructions to determine the best type of fogging oil to use and the proper procedure for fogging your engine.[5]

    • For some types of engines, you can simply spray fogging oil into the engine air intake while it is running. Spray a generous amount of fogging oil into the intake, then disconnect the fuel line. Continue spraying fogging oil into the air intake and allow the engine to continue running until it dies. The engine will probably put out a lot of white smoke during this process.
    • Alternatively, if you have completely drained the fuel from your engine, you can remove the spark plugs and spray fogging oil directly into the spark plug holes. Spin the engine by hand several times to coat the spark plugs. Put the plugs back in but do not connect the wires. This will keep your boat’s pistons from being subjected to air, dampness and other caustic materials when not in use.
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    Flush your engine block with antifreeze. Using antifreeze will prevent damage that can result from water freezing in your engine block. Antifreeze containing propylene glycol is environmentally friendly and recommended by nearly all manufacturers. Use the highest concentration of antifreeze available (-100). The procedure will differ depending on whether you have an inboard or outboard motor.

    • If you have an outboard motor, you can connect an antifreeze kit to your engine’s water intake after flushing with fresh water. Leave your engine running after performing the fresh-water flush, disconnect your water hose, and connect a hose attached to a tank of antifreeze to your water intake instead. Let the engine run while connected to the antifreeze tank until the tank is empty.[6]
    • For an inboard motor, take a large bucket of antifreeze (usually about five gallons) and insert the end of the water intake hose from the seacock into the bucket. Let the motor idle until you see antifreeze coming out of the exhaust outlet for at least 30 seconds. Replace the intake hose in the seacock.[7]
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    Change the oil. If you have an inboard motor, you should change the oil in your engine and transmission. This works best right after running the boat, while the oil is still hot. Hot oil flows more easily, and any contaminants or impurities will be suspended, making it easier to remove them. This is also a good time to replace your oil filter.[8]

    • Check your owner’s manual for recommendations on which type of oil to use. Engine oil is available in a variety of viscosities and service ratings, and different engines require different oil properties.
    • If you can, drain the old oil by removing the sump plug and allowing the oil to run out into a drainage pan or a […]

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