Quicksilver Blog

Winterize Your Outboard with Quicksilver Products

Winter brings the end of the season for many owners of outboard-powered boats. When you lay up your boat, correctly preparing your outboard motor for months of storage with premium Quicksilver® products will help assure that it’s ready to go next spring. In cold climates, freezing weather can cause costly damage to an engine that is not properly winterized. Even in milder climates, the end of the boating season is a convenient time to take care of annual maintenance that will keep your outboard running reliably.

The procedure for preparing your outboard for off-season storage is outlined in its owner’s manual, and with a few basic tools and the proper supplies, those inclined to do-it-yourself rather than visiting a marine service center can usually tackle the task. If you do not have the manual, a copy can usually be ordered from a dealer. Some engine manufacturers make downloadable PDF copies of many manuals available through their websites. The manual will have information specific to your outboard model, but here are some basic instructions from service experts.

Keep a Winterization Supplies List

See your outboard owner’s manual for guidance on supplies and tools specific to your motor.

Treat the Fuel

You should always store your boat with fresh fuel that has been treated with marine fuel stabilizer. Fuel that is left untreated will begin to oxidize and form a gum-like substance in the fuel system. This is especially true for outboards equipped with carburetors.

When possible, at the end of the season try to run your boat fuel tank almost empty. Then add fresh fuel before storage. If the fuel in your tank is more than a month old, and it is too late in the season to use it up, have it pumped it out and replace it with fresh fuel. If possible, refill the tank with ethanol-free fuel such as REC-90, a premium blend formulated specifically for recreational engines. Then add the correct amount of fuel stabilizer to the fresh fuel.

If you have an older boat with a vented fuel tank, it’s a good idea to fill the tank to keep condensation from forming inside it, but stop when the tank is about 95 percent full, because extreme temperature changes over the winter can cause the fuel to expand, potentially forcing gas out of the vent. Because newer tanks can’t freely vent to atmosphere and will not collect moisture from the air, they do not need to be full.

Marine techs recommend treating fuel for storage with Quicksilver Quickstor Fuel Stabilizer, one of the products in the Quicksilver Fuel Care System. These products are engineered to work together to optimize fuel, remove any leftover deposits from the engine and protect the fuel system over the winter months.

It is important to get that treated fuel into the entire fuel system by running the boat for about 10 minutes, either in the water or while connected to a garden hose (follow owner’s manual instructions if using a hose). Finally, replace the fuel filter. Now your motor’s fuel system will be ready to go next season.

Change the Oil

In a four-stroke outboard, the engine oil and filter should be changed every 100 hours or once a season, regardless of how many hours the engine was used. Storing the motor with old oil can expose internal engine components to moisture and acidic combustion byproducts, which can cause corrosion. The line of Quicksilver Precision Lubricants includes four-stroke engine oil for any outboard brand, specifically formulated for the unique needs of the marine environment. Never use automotive oil in a marine engine! Check your owner’s manual for the recommended lubricant products for your marine engine.

Many retail outlets will also stock a Quicksilver Oil Change Kit for many popular Yamaha and Mercury outboards. Each kit includes oil, an oil filter and a drain plug seal in a convenient box. Follow the oil change instructions in your owner’s manual, and always dispose of waste oil properly.

After you change the oil, it’s always a good idea to briefly start the engine again, to circulate fresh oil through the engine and to check for leaks. It’s not uncommon for the oil filter gasket to stick to the engine. If the old gasket isn’t removed, oil can leak past it after a new filter is installed. Engines have been ruined because the owner did not notice engine oil leaking out past a double gasket.

Fog the Engine

Ideally while the motor is still warm, four-stroke and conventional two-stroke engines should be treated with fogging oil to prevent corrosion within the engine. Remove the spark plugs and spray the fogging oil directly into each cylinder, following the directions on the can. Use a fogging oil product that is specially designed for use during winterization, such as Quicksilver Storage Seal.

For direct fuel injected (DFI) two-stroke engines such as Evinrude E-TEC, Yamaha HPDI and Mercury OptiMax® models, instead of using fogging oil, squirt 1 ounce of DFI outboard oil into each cylinder through the spark plug hole (follow the owner’s manual instructions for your engine model). A small oil can with a long flexible neck works well for this task. Put a coat of anti-seize lubricant on the spark plug threads before carefully replacing the plugs. Use new spark plugs, correctly gapped, per the service schedule in your owner’s manual.

Change the Gear Lube

The gear lube in the outboard lower unit should also be changed every 100 hours or once a season. Check your owner’s manual for the specific service interval. Any water in the gear lube can freeze and expand during storage, potentially cracking the gearcase.

As you drain the old lube, inspect it carefully. If gear lube appears white or creamy, it may indicate the presence of water in the lubricant. This is an indication that the propeller shaft seal may be compromised and is allowing water to contaminate the lubricant, which could cause severe damage to the gears. If water is suspected to be present in the gearcase, a pressure check of the gearcase should be completed by an authorized dealer.

Refill the gearcase with fresh lubricant using a quality marine-specific product such as Quicksilver Premium Gear Lube, following the instructions in your owner’s manual.

Check the Prop Shaft

With some gearcases, you will have to remove the propeller in order to change the lube. Even if your engine doesn’t require that, it’s a good idea to pull off the prop. If your prop is nicked or bent, the offseason is a good time to send it out for repair at a propeller shop so it will be ready to go in the spring. Your dealer can often make arrangements for prop tuning or repair.

After removing the prop, check the prop shaft for fishing line. Remove the large thrust washer that is located behind the prop on some hub styles. The fishing line is often coated with grease and hard to see. Use a sharp pick or a small screwdriver to pull at the area around the prop-shaft seal to loosen any line that might be present. Over time, the forward thrust of the prop presses the line into the rubber prop-shaft seal. If the seal is damaged, water can enter the gearcase and cause significant damage.

If the prop is in good condition, either reinstall it or store it separately from the engine to discourage thieves. Always coat the prop shaft with a quality marine grease such as Quicksilver 2-4-C Marine Lubricant before reinstalling the prop, and tighten the prop nut to the torque specification listed in the owner’s manual.

Check the Power Trim Fluid 

Check your owner’s manual for specific instructions for your outboard model. You will probably need to tilt the engine all the way up to get to the pump. The fluid inside should be bright red. If so, check the level, and top it off if it’s low. Trim fluid that is pink or milky indicates the presence of water, which means there could be a leak somewhere in the system, and the trim pump should be inspected by a qualified dealer.

Check Sacrificial Anodes

Sacrificial anodes (or zincs, as they are often called) are designed to protect the motor’s other submerged metals from galvanic corrosion. Most outboard motors have several sacrificial anodes, and they can be located by consulting the owner’s manual. Sacrificial anodes should be replaced when they are 50% deteriorated.

Lubricate any Grease Points 

Most outboards have some grease zerks or other lubrication points that should be serviced. Consult your owner’s manual to see where your outboard needs grease.

Coat the Powerhead

As a last step, coat the powerhead with a rust-inhibitor product such as Quicksilver Corrosion Guard, which is especially effective for motors used in saltwater. It displaces water and forms a barrier to protect painted and unpainted surfaces from corrosion caused by saltwater either on the powerhead or in the atmosphere. Corrosion Guard can also be applied to prevent corrosion from forming on the lower unit and power trim motor.

Touch Up Any Nicks or Scratches

Inspect your engine’s lower unit, and repaint any wear-and-tear marks. Some outboard dealers carry a complete line of paint products – primer, color and clear coat – that are an exact match to the factory finish.

Check and Maintain the Battery 

If yours is a wet-cell lead-acid battery, inspect the fluid level and add distilled water, if needed. Be sure the battery is fully charged, remove it from the boat, and store it in a cool, dry place. Storing the battery on a maintenance charger will keep it charged and fresh until spring.

Store the Engine Upright

Whether the boat is stored on a trailer or a rack, the motor should be trimmed down to its vertical position so that any water remaining in the engine can drain. If water trapped in the engine freezes, it could cause serious damage.

In some situations, mice can be a problem. They could be able to get under the motor cowl and chew on wiring. Some dealers swear by this tactic: Fabric softener sheets, or drier sheets, are believed to repel mice. Just do not forget to remove the sheet before you hit the water next season.