Winterizing Your Outboard Motor

Oh I hate this time of year! The leaves, which were pretty for a couple of weeks, are falling from the trees. The skies are getting more and more grey each morning, the winds are starting to bite and the sun just doesn't seem to shine as much.

Every winter, I'm the last guy around here to put the boat into storage. I'm the guy still taking her out, right into December, canvas up, sweater and layers bundled. It's probably one of the reasons I love my outboard so much, since I can just leave her upright on the transom when I get home, and she'll self drain the water JUST in case we have a frost or two before I get around to really putting her to bed for the winter.

I've got boating friends all over the country. And I was always surprised to hear that many of my friends down south and out west also put their boats to bed. Even though their temperatures aren't nearly as bad in the winter, they find that they often take at least a month or two off in the winter.

But I was equally surprised to hear that some of them don't take any additional steps to protect their boat while in storage. Oh the horror, I thought when I first heard that. Sometimes they get away with it, but other times, come spring, I get an email asking about carburetor rebuilding. I usually bite my tongue when asking how the carbs got gummed up in the first place.

The bottom line is this, taking extra time to store the boat and motor properly at the end of each season or before any extended period of storage will greatly increase the chances of satisfactory service at the next season (or whenever you get around to getting the boat out again).

Remember, that next to hard use on the water, the time spent in storage can be the greatest enemy of a boat and motor.

Ideally, boats should be used regularly. If weather in your area allows it, don't store the motor, enjoy it. Use it, at least on a monthly basis. It's best to enjoy and service the boat's steering and shifting mechanism several times each month. A small amount of time is spent in such maintenance will reward you with performance, increased longevity and greatly reduced maintenance expenses.

Unfortunately, things like weather, work or other factors will interfere with time for enjoying a boat and motor. If you must place them in storage, take time to properly winterize or prep the boat and motor for storage. This will be your best shot at making time stand still for them.

For many years there was a widespread belief that simply shutting off the fuel at the tank and then running the powerhead/engine until it stops constituted prepping the motor for storage. Right? Well, WRONG!

First, it is not possible to remove all fuel in the carburetor(s) or fuel injection system by operating the motor until it stops. Considerable fuel will remain trapped in the carburetor float chamber (or vapor separator tank of fuel injected motors) and other passages, especially in the lines leading to carburetors or injectors. The only guaranteed method of removing all fuel from a carbureted motor is to physically drain the carburetor(s) at the float bowl(s). And, though you should drain the fuel from the vapor separator tank on most fuel injected motors (when possible), you still will not be able to remove all of it from the sealed high-pressure lines.

Depending upon the length of storage, you can use fuel stabilizer as opposed to draining the fuel system; but if the motor is going to be stored for more than a couple of months at a time, draining the system is really the better option.

Here's a tip, Up here in the northeastern U.S., we always start adding fuel stabilizer to the fuel tank with every fuel fill-up starting sometime in late August or early September. That helps to make sure that we'll be at least partially protected if the weather takes a sudden turn and we haven't had a chance to complete winterization yet.

Proper storage involves adequate protection of the unit from physical damage, rust, corrosion and dirt. The following steps provide an adequate maintenance program for storing the unit at the end of a season.

ANOTHER TIP: If your boat or motor requires one or more repairs, PERFORM THEM NOW or during the off-season. Don't wait until the sun is shining, the weather is great and you want to be back on the water. That's not the time to realize you have to pull of the gearcase and replace the seals. Don't put a motor that requires a repair into storage unless you plan on making the repair during the off-season. It's too easy to let it get away from you and it will cost you in down time next season.

Where to Store Your Boat and Motor:

Ok, a well lit, locked, heated garage and work area is the best place to store your precious boat and motor, right? Well, we're probably not the only ones who wish we had access to a place like that, but if you're like most of us, we park our boat and motor wherever we can.

Of course, no matter what storage limitations are placed by where you live or how much space you have available, there are ways to maximize the storage site.

If possible, select an area that is dry. Covered is great, even if it is under a carport or sturdy portable structure designed for off-season storage. Many people utilize canvas and metal frame structures for such purposes. If you've got room in a garage or shed, that's even better. If you've got a heated garage, bless you, when can we come over? If you do have a garage or shed that's not heated, an insulated area will help minimize the more extreme temperature variations and an attached garage is usually better than a detached for this reason. Just take extra care to make sure you've properly inspected the fuel system before leaving your boat in an attached garage for any amount of time.

If a storage area contains large windows, mask them to keep sunlight off the boat and motor, otherwise use a high-quality canvas cover over the boat, motor and if possible, the trailer too. A breathable cover is best to avoid the possible build-up of mold or mildew, but a heavy duty, non-breathable cover will work too. If using a non-breathable cover, place wooden blocks or length's of 2 x 4 under various reinforced spots in the cover to hold it up off the boat's surface. This should provide enough room for air to circulate under the cover, allowing for moisture to evaporate and escape.

Whenever possible, avoid storing your boat in industrial buildings or parking areas where corrosive emissions may be present. The same goes for storing your boat too close to large bodies of saltwater. Hey, on the other hand, if you live in the Florida Keys, we're jealous again, just enjoy it and service the boat often to prevent corrosion from causing damage.

Finally, when picking a place to store your motor, consider the risk or damage from fire, vandalism or even theft. Check with your insurance agent regarding coverage while the boat and motor is stored.

Preparing the Boat and Motor for Storage

The amount of time spent and number of steps followed in the storage procedure will vary with factors such as the length of planed storage time, the conditions under which boat and motor are to be stored and your personal decisions regarding storage.

But, even considering the variables, plans can change, so be careful if you decide to perform only the minimal amount of preparation. A boat and motor that has been thoroughly prepared for storage can remain so with minimum adverse affects for as short or long a time as is reasonably necessary. The same cannot be said for a boat or motor on which important winterization steps were skipped.

1. Thoroughly wash the boat motor and hull. Be sure to remove all traces of dirt, debris or marine life. Check any water fittings, inlet(s) and, on jet models, the impeller grate for debris. If equipped, inspect the speedometer opening and any gearcase drains for debris (clean debris with low-pressure compressed air or a piece of thin wire).

1. On 4-stroke models, change the engine crankcase oil and, if applicable, service the oil filter. Refill the crankcase and gearcase with fresh oil. The motor should be run after the oil is changed to distribute the fresh/clean oil throughout the powerhead. Of course, in most cases, the motor should be run for flushing and fogging anyway. Besides treating the fuel system to prevent evaporation or clogging from deposits left behind, coating all bearing surfaces in the motor with FRESH, clean oil is the most important step you can take to protect the engine from damage during storage. NEVER leave the engine filled with used oil that likely contains moisture and, in the case of 4-stroke crankcase oil, acids and other damaging byproducts of combustion that will damage engine bearings over time.

1. Stabilize the engine's fuel supply using a high quality fuel stabilizer and take this opportunity to thoroughly flush the engine cooling system at the same time

1. Add an appropriate amount of fuel stabilizer to the fuel tank and top off to minimize the formation of moisture through condensation in the fuel tank. Attach a flushing attachment as a cooling water/flushing source. Start and run the engine at fast idle approximately 10-15 minutes. This will ensure the entire fuel supply system contains the appropriate storage mixtures.

1. Just prior to stopping the motor, fog the engine using a commercially available fogging lubricant (or by following the instructions in your boat's owner's manual or in the appropriate Seloc manual. Keep in mind that some motors require special steps for fogging, such as adding a certain oil to the fuel/water separator before running the motor). When using a spray fogging oil, spray the oil alternately into each of the carburetor or throttle body throats (you'll likely have to remove an air intake silencer/flame arrestor for access). When properly fogged, the motor will smoke excessively, will stumble and will almost stall.

1. Stop the engine and remove the flushing source. On outboards, keep it perfectly vertical in order to allow the cooling system to drain completely, especially if the outboard might be exposed to freezing temperatures during storage. On stern drives, inboards and some older outboards, be sure to remove the drain plugs or open the necessary drain fittings. (Again, see your owners manual or the appropriate Seloc manual, some motors have specific requirements when it comes to draining. Many inboards use antifreeze poured into the raw water system to protect areas where water may become trapped).

1. Drain and refill the engine gearcase while the oil is still warm. Take the opportunity to inspect for problems now, as storage time should allow you the opportunity to replace damaged or defective seals. More importantly, remove the old, contaminated gear oil now and place the motor into storage with fresh oil to help prevent internal corrosion.

1. Finish fogging the motor manually through the spark plug ports. Tag and disconnect the spark plug leads, remove each spark plug and then spray a generous amount of fogging oil directly into the spark plug ports. Turn the flywheel slowly by hand (in the normal direction of rotation) to distribute the fogging oil evenly across the cylinder walls. On electric start models, the starter can be used to crank the motor over in a few short bursts, but make sure the spark plugs leads remain disconnected and grounded to the powerhead (away from the spark plug ports) to prevent accidental combustion. If necessary, re-spray into each cylinder when that cylinder's piston reaches the bottom of its travel. Reinstall and tighten the spark plugs, but leave the leads disconnected (and GROUNDED) to prevent further attempts at starting until the motor is ready for recommissioning.

1. On carbureted outboard motors, if the motor is to be stored for any length of time more than one off-season you really SHOULD drain the carburetor float bowls. Honestly, it is a pretty easy task and we'd recommend doing that for all motors, even if they are only going to be stored for a few months. To drain the float bowls, locate the drain screw on the bottom of each bowl, place a small container under the bowl and remove the screw. Repeat for the remaining float bowls on multiple carburetor motors. (If on the odd chance your outboard carburetor doesn't have a drain screw you'd have to remove the float bowl, but the vast majority I've encountered have always had a drain screw).

1. Many fuel injected motors use a vapor separator tank which also MAY contain a drain screw. When equipped, it is a good idea to completely drain the tank of fuel. This will help protect the fuel lines and components in the tank from possible damage by deteriorating fuel.

1. For outboards equipped with portable fuel tanks, disconnect and relocate them to a safe, well-ventilated, storage area, away from the motor. Drain any fuel lines that remain attached to the tank. It's a tough call whether or not to drain a portable tank. Plastic tanks, drain em' and burn the fuel in something else. Metal tanks, well, draining them will expose them to moisture and possible corrosion, while topping them off will help prevent this, so it probably makes more sense to top them off with treated fuel.

1. For boats with permanently installed fuel tanks, there's a huge debate going whether or not it is better to drain your fuel tanks completely during storage or to top them off. The first option allows you to fill the tank with fresh fuel when the boat is removed from storage. But depending on temperature swings during storage you could amass a significant amount of water in the tank from condensation. You'd need to drain this water before recommissioning. The later option is the easiest, especially for shorter term storage (one winter) and it prevents the formation of condensation, as there just isn't room for much air/moisture in the top of the filled tank.

1. Remove the battery or batteries from the boat and store in a cool dry place. If possible, place the battery on a smart charger or Battery Tender, otherwise, trickle charge the battery once a month to maintain proper charge. Remember that the electrolyte in a discharged battery has a much lower freezing point and is more likely to freeze (cracking/destroying the battery case) when stored for long periods in areas exposed to freezing temperatures. Although keeping the battery charged offers one level or protection against freezing; the other is to store the battery in a heated or protected storage area.

1. For models equipped with a boat mounted fuel filter or filter/water canister, you may wish to clean or replace the filter at this time. However, if the fuel system was treated, the engine mounted fuel filters should be left intact until spring, so the sealed system remains filled with treated fuel during the storage period.

1. For 2-stroke motors with external oil tanks, if possible, leave the oil supply line connected to the motor. This is the best way to seal moisture out of the system. If the line must be disconnected for any reason (such as to remove the motor or oil tank from the boat), seal the line by sliding a snug-fitting cap over the end.

1. Perform a complete lubrication service on the boat and motor.

1. Except for Jet Drive models, remove the propeller and check thoroughly for damage. Clean the propeller shaft and apply a protective coating of grease. Now is the time to replace or service a damaged propeller. NOT at the start of the next season.

1. On Jet models, thoroughly inspect the impeller and check the impeller clearance. Just like damaged propellers, now is the time to replace or service a damaged impeller. NOT at the start of the next season.

1. Check the motor for loose, broken or missing fasteners. Tighten fasteners and, again, use the storage time to make any necessary repairs.

1. Inspect and repair all electrical wiring and connections at this time. Make sure nothing was damaged during the season's use. Repair any loose connectors or any wires with broken, cracked or otherwise damaged insulation.

1. Clean all components under the engine cover and apply a corrosion preventative spray.

1. Too many people forget the boat and trailer, don't be one of them.

1. Cover the boat and outside painted surfaces of the motor with a fresh coating of wax and then cover it with a breathable cover.

1. If possible, place the trailer on stands or blocks so the wheels are supported off the ground. Make sure the bow is raised higher than the stern to promote draining of rain water or snow.

1. Check the air pressure in the trailer tires. If it hasn't been done in a while, remove the wheels to clean and repack the wheel bearings.

1. Sleep well, since you know that your baby will be ready for you come next season.

Fig 1. Always keep some fuel stabilizer on hand, and starting in the fall, add it to the tank with each fill-up, then you'll be ready for an unexpected layover

Fig 2. If possible, block the trailer up off the ground and make sure the front end is raised higher than the rear to help promote draining of water from the cover (or the boat)

Fig 3. Run the motor on a flush fitting in order to both distribute the stabilized fuel throughout the system and to clean the cooling passages, then properly fog the motor for storage

Fig 4. Remove the battery or batteries from the boat and keep them charged with an automatic charger

Fig 5. You can also use a non-automatic charger to maintain your battery, but follow the instructions that came with the charger closely to prevent damaging the battery through overcharging

Fig 6. Outboards should be stored in a vertical position so they self-drain and do not collect rainwater (both of which could potentially lead to hazards in freezing weather)