It’s mid-October, and up here in Wisconsin it’s time to winterize the boat and get the snow blower started. I’m a by-the-book kind of guy when it comes to maintenance, and that goes for off-season lay-up of my outboard. The book in question is the owner’s manual, and if you handle this end-of-year service yourself or farm it out to a pro, that winter-storage section of the manual should be your guide.


A close shot of the hose and muff device over the water intakes. Unlike a flush fitting, the muff directs water into the water pump, protecting the impeller from damage.

Whether you’re dealing with the latest four-stroke powerhouse or Grandpa’s ancient Sea Horse kicker, the basic steps include treating the fuel system to a good dose of stabilized gas, changing the gearcase lube, fogging the powerhead and general lubrication of moving parts with grease or oil. But even if you follow the owner’s manual to the letter, there are ways to screw up, mistakes that could cost you big-time come spring. So DON’T do any of the following:

Don’t Store the Motor Tilted Up

When you park the boat for the winter keep the motor trimmed or tilted down, especially if it’s outdoors. This will allow all of the water to drain out of the motor’s cooling system. If it’s tilted up, some water may remain in the motor, where it can freeze and cause a cracked block or a ruined water pump housing. Even if you think the motor is fully drained, if you store it outdoors and tilted up, rain or snow could enter the exhaust passages through the prop hub, freeze there, and crack something.


You should change the gear case lube once a year, and fall is the best time if you live where it might freeze. If the lube comes out nice and oily, your gearcase is in good shape. If it’s cloudy or grey, water has gotten into the case and it needs to be fixed.

Don’t Store the Motor Wrapped Up

I see this all the time up here: a boat stored outside for the winter, carefully covered, with its motor wrapped in plastic. The owner figures he’s going to keep rain and snow off his outboard, but he’s set himself up for under-cowl corrosion problems. The cowl is vented and designed to breath as the temperature warms and cools. This keeps moisture from collecting on the powerhead. If you seal the motor in a home-made prophylactic made from a garbage bag and duct tape, instead of circulation you’ll get condensation, especially in the cool, damp months of winter. This can lead to corrosion in the charging system, on wiring connectors, and on the throttle and shift linkages. So don’t cover the motor. If you have your boat shrink-wrapped, ask them to either work around the motor, or leave gaps around the transom so some air can get to the motor.

Don’t Start the Motor Out of the Water

Winterizing action at Spellman’s Marina in Oshkosh, Wis., where more than 50 boats were waiting to be laid up this week. Here a tech injects fogging oil into Johnson V-4 two-stroke powerhead while it’s running. Note the garden hose “muffs” over the water inlets on the lower unit.

Winterizing action at Spellman’s Marina in Oshkosh, WI, where more than 50 boats were waiting to be laid up. The tech injects fogging oil into a Johnson V-4 two-stroke powerhead while it’s running. Note the “muffs” over the water inlets.

All outboards have a self-draining cooling system. There is no reason to start the motor with the notion that you are going to purge the last drops from the water pump housing. Maybe the sound of an unmuffled two-stroke is irresistible, but don’t do it. Starting the motor “dry,” even for just a moment, can dramatically shorten the life of the water pump impeller, or even destroy it. It needs water for lubrication. Of course, you won’t know that you’ve messed up the impeller until the motor overheats on the opening day of fishing season next spring. If you need to start the motor on dry land (to get treated fuel into the engine, for example), use a hose and the “earmuff” device that clamps over the water intake. Do not start the motor with a hose connected to the fresh-water flush port. This may circulate water through the powerhead, but not to the pump.

Don’t Ignore Gearcase Service

A few years ago my brother-in-law, who lives in Alaska, was shopping for a new gearcase for his Evinrude 115 after neglecting to check the gearcase lube. It was full of water, which froze, which cracked the case. You need to change this lube once a year because it does “wear out,” and changing it is also the best way to see if any water is getting into the gearcase. If the lube comes out grey or cloudy, you’ve got water and a problem. It’s probably a bad propshaft seal (see our previous story about fishing line fouled on the propshaft). But if there’s been water in the case for awhile, there could also be gear or bearing damage. This needs to be fixed. Might as well do it now and be ready to go in the spring. Note to Evinrude E-TEC owners: I know your manual says the gearcase lube is good for three years. But every tech I’ve talked to says to change it anyway. It’s cheap insurance.

Don’t Leave the Battery in the Boat

It’s not part of the motor, but this is such a common mistake I’ve got to mention it. A battery won’t freeze if the electrolyte has a good charge. But if it goes low and loses that charge, it will freeze and then be ruined. (And maybe crack and leak in your bilge.) Ideally, you want to take the batteries out of the boat, give each a full charge, and then store them in a cool (about 40 degrees) but not cold place. Even better is to store them hooked up to a maintenance-type battery charger like the Battery Tender Plus. Then come spring, they will be fully charged and ready for action.

Editor’s Note: Charles Plueddeman, our Outboard, Trailer, and PWC Expert, is a former editor at Boating Magazine and contributor to many national publications since 1986.