How to Winterize an Outboard Motor

What You’ll Need to Winterize an Outboard Motor

• Fuel stabilizer – helps keep the fuel in the tank from breaking down.
• Oil and oil filter – prevents corrosion and buildup by providing clean oil to the engine.
• Fogging oil – prevents rust and corrosion in the cylinders.
• Muffs or flushing attachment – allows you to run the engine without water.
• Garden hose – supplies water while it is being flushed.
• Spark plug socket – used for removing and replacing them.
• Battery charger or battery tender– helps maintain battery charge over winter months.
• Fuel filter – keeps the system clean, preventing buildup.
• Rags and cleaning supplies – use these for wiping down before winterizing.

Flushing Your Outboard Motor

Running clean freshwater through your engine helps to flush out any salt, minerals, and debris that may have built up over time. Saltwater can be particularly corrosive, so regular flushing is necessary to protect it from wear and tear. 

1. Turn off the engine and remove the flushing plug or attachment from the motor’s lower unit if one exists; otherwise, you must use flushing muffs.
2. Attach the muffs or flushing attachment to a garden hose and a water sp and ensure the supply is turned on.
3. Place the muffs or flushing attachment over the water intake of your motor.
4. Turn on the water supply and start your engine, leaving it in neutral.
5. Let it run for 10-15 minutes to allow clean water to flush out salt or mineral buildup. Check the manufacturer’s instructions for specific guidance.
6. After flushing, turn off the engine and water supply, then remove the muffs or flushing attachment from the intake.
7. Remove the flushing plug or flushing attachment.

Oil Change

Before you store your motor away for the winter, it is essential to change the oil. Used oil can be filled with contaminants and debris, leading to damage. Replacing it with clean oil before storage is vital to maintain your engine’s health and ensure it runs smoothly all year round.

1. Start by running the engine for a few minutes to warm up the oil, making it easier to flow out.
2. Turn off the engine and remove the plug from the oil pan, using an oil pan to collect the used oil.
3. Once all of the used oil has been removed, replace the plug.
4. Remove and replace the old oil filter with a new one.
5. Add new oil according to the owner’s manual for the type and amount of oil.
6. Check and top off the oil level if necessary.
7. Start the engine again and let it run for a few minutes to circulate new oil.
8. Turn off the engine again, and check and top off the oil level if needed.

Remember that not all outboards, especially smaller ones, have an oil pan. For those, the process of changing the oil may differ. Consult your owner’s manual for specific instructions.

Oil Filters

Changing the oil filter as part of an oil change is essential to ensure the health and performance of your outboard. The filter works to remove contaminants and debris from the oil.

1. First, find the oil filter. Depending on the make and model of your motor, it may be located in different places.
2. Use an oil filter wrench to loosen the old one counterclockwise. Make sure to use the correct size wrench to avoid any damage.
3. Unscrew it by hand when it is loose, then remove it entirely from the motor.
4. Wipe off any excess oil or debris with a clean cloth.
5. Add fresh oil onto the seal or gasket before installing the new filter and tighten it by hand – don’t overdo it!
6. Finally, use that same oil filter wrench to give it another quarter to half turn until snug.

Checking and Replacing Gear Oil in the Lower Unit

Proper maintenance of your lower unit and gear oil ensures smooth operation and prevents damage during winter storage.

Step 1: Locate the drain and fill plugs

First, find the plugs on your motor’s lower unit. They are typically located close to each other, with the drain plug at the bottom and the fill plug above it.

Step 2: Remove the old gear oil

Place an oil pan or container beneath to catch the old gear oil. Remove the plugs, allowing the old gear oil to flow. Be patient, as this might take a few minutes.

Step 3: Inspect the old gear oil

Take a close look at the expelled gear oil. If you notice water or metal shavings, this could indicate a potential issue, such as a damaged seal or worn gears. In such cases, consult a professional for further inspection and repair.

Step 4: Fill with new gear oil

Using a gear oil pump or squeeze bottle, fill the lower unit with the type of marine gear oil recommended by your motor’s manufacturer. Fill from the drain hole until the oil starts to come out of the fill hole.

Step 5: Replace the plugs

Once filled with new gear oil, quickly replace the plug. Then, fit a new sealing washer on the fill plug. Tighten both securely, but avoid over-tightening.

Fuel System

Preparing the fuel system for winter is crucial to prevent breakdown and sediment buildup, which can eventually cause damage. Another issue that can arise is water accumulation in the tank, leading to damage and other complications. 

Fill the tank with fresh gas.

1. Add a stabilizer.
2. Run the engine for 10-15 minutes to allow it to circulate throughout.
3. Turn off the fuel valve, disconnect the fuel line, and run the engine until it uses all the fuel. This prevents any excess from blocking the carburetor or injectors.
4. Drain any remaining fuel from the carburetor or injectors following the manufacturer’s instructions.
5. Replace the fuel filter to ensure a clean and buildup-free system.
6. Inspect the lines and fittings for signs of wear or damage and replace them if necessary.

Whenever possible, opt for ethanol-free gasoline, as ethanol can attract moisture and cause deposits.

Fogging the Engine

Fogging is a critical step in winterizing if it will be stored for an extended period. This process involves spraying fogging oil into the cylinders, which coats the internal components to protect them from rust and damage. 

1. Remove spark plugs, then spray fogging oil into each hole using an applicator or spray can. Make sure to spray for a few seconds in each cylinder.
2. Turn over the engine several times with a starter motor or by hand to distribute the fogging oil inside.
3. Reinstall and tighten spark plugs according to the manufacturer’s specifications.
4. Turn over the engine several more times with a starter motor or by hand to ensure it is freely turning.

Battery

If a battery is neglected, it can lose its charge, freeze, or corrode and be damaged or have a shorter lifespan.

1. Disconnect the negative cable from the battery to prevent any power drain.
2. Clean the terminals and connections with a wire brush or battery terminal cleaner to remove corrosion or buildup.
3. Check fluid levels – add distilled water as needed to bring it up to the proper height.
4. Fully charge the battery with a charger or battery tender – this will help prolong its lifespan!
5. Periodically check the charge level and recharge as necessary to always have a full charge.
6. Store the battery in a cool, dry place, away from heat sources. Avoid placing it directly on concrete, which can lead to faster discharge.
7. Inspect periodically for signs of damage, such as cracks or leaks.

If your battery is a maintenance-free AGM (Absorbent Glass Mat) or gel cell type, you don’t need to check the fluid levels, as they do not require maintenance.

Lubrication

Proper lubrication of the motor’s moving parts is crucial for your equipment’s smooth operation and longevity. 

1. Gather necessary tools and materials: Get marine grease, an applicator gun, lubricating oil, and clean rags required for maintenance.
2. Locate grease points: Check your owner’s manual to identify the points, including swivel systems, tilt tube, steering, and propeller shaft.
3. Clean the points: Remove dirt or debris using a clean rag.
4. Apply marine grease: Load the grease gun and attach it to the fitting at each point. Pump the grease gun until fresh grease starts seeping out of the joints. Be careful not to use too much, which can cause excessive joint pressure.
5. Lubricate moving parts: Apply a light coating of lubricating oil to any moving parts that require lubrication, such as the throttle and shift linkages. Refer to the owner’s manual for the specific components that require lubrication.
6. Clean up: Remove the excess from the components using a clean rag to prevent debris accumulation.

Inspecting and Replacing the Impeller

The impeller and water pump are vital for circulating water through the cooling system. Failure to regularly check and replace a damaged impeller can lead to overheating and potential damage. 

1. Locate the water pump: It is typically housed within the lower unit.
2. Remove the lower unit: Disconnect the shift linkage and any other connections as per the manual. Then, remove the bolts holding it in place and slide them off.
3. Check the impeller: Remove the housing to expose the impeller and check for visible signs of wear, such as cracks, tears, or missing vanes. If any damage is present, it’s time to replace the impeller.
4. Replace the impeller (if necessary): Remove the damaged impeller and replace it with a new one, ensuring proper seating and orientation of the vanes per the manufacturer’s instructions.
5. Reassemble the water pump: Reassemble the housing and check all seals and gaskets for damage or wear. Replace them as needed.
6. Reinstall the lower unit: Carefully align the pump shaft and drive shaft, and reconnect the shift linkage and other connections before securing them with the bolts. Remember to follow the manufacturer’s specified torque settings.

Clean the Outboard Exterior

1. First, rinse off the motor with clean water to remove any salt or dirt buildup.
2. Use a mild detergent, soap, water, and a soft-bristled brush or sponge to wash the exterior surfaces. Avoid abrasive cleaners that could damage the paint or decals.
3. Then, rinse the motor thoroughly and dry it off with a clean cloth.
4. Apply a coat of wax or polish on the exterior according to manufacturer instructions – this will help protect from damaging UV rays and other environmental factors.
5. Check the propeller and anodes for any signs of wear or damage – replace if necessary.
6. Lastly, wipe down the motor with a dry cloth to remove any excess wax or polish.

Outboard Boat Motor Winter Storage

• When storing your motor, keep it in a cool, dry place, away from any heat or flames.
• Use a stand or cradle for support to ensure the motor remains undamaged. The engine should be stored vertically so the oil won’t seep into the powerhead.
• Covering the motor with a breathable cover will protect it from dust and debris.
• Removing spark plugs and adding oil to each cylinder can help prevent any damage if stored for an extended period.
• Additionally, running the engine periodically during storage keeps components lubricated and helps stop the build-up of debris and sediment.
• Finally, remember to check on the battery periodically and recharge when needed to maintain its full charge.

If your outboard is stored outdoors, ensure it is adequately covered and protected from the elements, such as rain, snow, and UV exposure. Invest in a waterproof cover to keep it safe and dry. 

2-Stroke Specific Steps

While the general winterizing process is similar for 2-stroke and 4-strokes, there are some specific steps needed:

1. Carburetor: Since 2-strokes have carburetors, removing any fuel from the carburetor is essential to prevent gum and varnish buildup. Consult your engine’s manual for specific instructions.

4. Fogging: Fogging a 2-stroke requires a slightly different approach due to its design, You should also use fogging oil specifically designed for 2-stroke engines and follow the manufacturer’s instructions.

Final Thoughts

In conclusion, taking the time to winterize your outboard is vital to maintaining its performance and longevity. By following this comprehensive guide, you can protect your engine from the damaging effects of cold temperatures, corrosion, and debris buildup.

Remember that the winterization process may vary depending on the severity of your winter climate, so be sure to adapt your approach accordingly. With proper care and maintenance, your outboard motor will be ready to hit the water again as soon as the weather warms up, ensuring many more seasons of enjoyable boating experiences.