Winterizing Outboard Motors

Easy things you can do to be ready for spring fishing in Ontario.

With the investment anglers have in their boats and motors, it’s surprising to see the number of people who have problems on the season's first trip, especially when a little maintenance in the fall would all but eliminate them. Sitting under a pile of snow all winter can really take a toll on an outboard motor and, regardless of how well your engine worked last season, without a little care before winter, you’re setting yourself up for trouble next year.

Here are a few easy things you can do to help keep your motor in good shape through the winter so it’s ready to go next spring.

changing boat oil

Change the Lower Unit Oil

The first thing to do is change the oil in the lower unit. This ensures that 

  1. There is no water in the gear case that could freeze and cause a crack
  2. Can alert you to any potentially serious internal problems.
tilting a boat engine

Change the Gear Oil

To change the gear oil, start by tilting the engine into the “down” position so that it is as vertical as possible. Place a catch-tray under the engine and locate the two or three screws on one side of the lower unit housing. If you have a large outboard, you may need to remove the propeller to access the lowest of these.

removing screws on the gearcase of a boat

Remove the bottom screw first, then the top one(s) and let all the oil drain out of the gear case. The lower plug will have a small magnet on it that is there to attract any metal filings that may have worn off the gears. A few filings are normal, but if you notice an unusually high amount of them it could be a sign of pending engine damage—have the engine checked by a professional. While you have the plugs out, replace the small gaskets on all of them and clean off any debris.

draining boat oil

While the oil is draining, take a look at its colour. The old oil should look like old oil; if it looks whitish and creamy, it’s a sign that water has been getting into the engine somehow. Water in the gearcase is a guaranteed recipe for disaster so, if the old oil doesn’t look right, take the engine to a dealer and have it checked.

re-filling the boat gearcase

Once the old oil has drained, re-fill the gearcase with the manufacturer’s recommended oil. Always fill the gearcase from the bottom hole and keep pumping it in until oil begins to ooze from the top hole.

re-installing the upper plug of the gearcase

When you see oil coming out of the top hole, re-install the upper plug(s) to create a vacuum. Then remove your oil pump or tube of lubricant and quickly re-install the lower plug.

fill the gas tank of a boat

Fill the Gas Tank and Add Fuel Stabilizer

Next, fill the gas tank(s) and add fuel stabilizer if the boat won’t be used for several months. This eliminates the possibility of condensation forming inside the gas tank, which could contaminate the fuel and possibly foul the engine. The stabilizer will also prevent the fuel from breaking down and becoming gummy, which can happen to untreated fuel in as little as three months.

Don't Forget These Motor Winterizing Tasks

  • It’s a good idea to change the spark plugs every season too, especially if you use your rig a lot, and by doing it in the fall, you’ll ensure an easy start-up in the spring.
  • Finally, take a grease gun and give a squirt to any of the grease fittings on the engine. Visually check the engine, especially around the propeller, and remove any fishing line, vegetation, etc.
  • Give the motor a quick wash to keep it looking good, cover it up, and you’ll be all set to go when next spring rolls around.
About Bob Izumi

Bob Izumi is a Canadian professional angler, and the host of Bob Izumi's Real Fishing Show. He is most known for his success in bass fishing, and was awarded angler of the year in 2004.

Recommended Articles

Eating Northern Pike

The Best Recipe to Cook This Fish

Algonquin Brook Trout

A Fishing and Canoe Trip on Algonquin's Upper Nipissing River

Ontario Brook Trout

Fish these 10 sweet spots.

Shoreline Strategies

Try These 2 Techniques For Targeting Winter Brook Trout

Spring Walleye

Try These Tips on Your Next Ontario Walleye Fishing Trip

5 Places to Shore Fish

Fish’n Canada shows you where to go shore fishing in Ontario.

10 Facts About Lake of the Woods

10 facts amazing about this massive Northwest Ontario Lake!

Leuenberger Air Service Is Your Ticket to Ontario's Best Fishing

Discover remote outpost fishing for northern pike, walleye, and whitefish

3 Great Ontario Walleye Destinations

Karl of Extreme Angler recommends must do walleye lakes in Ontario.

5 Flies for Ontario’s Most Popular Species

In these northern waters live of the most revered fish anglers wish to target on fly.

Fly Fishing the Grand River with Mikey Metcalfe

A Walk-and-Wade Guided Trip for Brown Trout

Buck Lake Lodge

Fishing Walleye at Witches Nose

A Guide to Fly-in Ontario Lodges

Today’s fly-in fishing vacations are no more expensive than most other getaways.

20 Years With Fish TV!

Fish TV discusses their favourite Ontario catches

Top Flies for Northern Pike

Try These Go-to Flies and Tips on Your Next Trip

3 Surefire Strategies for Canadian Muskies

Fishing for Ontario Musky

The Eagle has Landed

If you're looking to make your Ontario fishing dreams come true, this is the place to do it.

Best WhiteFish Tactics

In Part Two, Learn Best Rods, Reels and Lure Presentations for Whitefish

The Big Bass List: 5 Incredible Hotspots in Northern Ontario

From hidden back bays of Sunset Country to the legendary "wolf packs" of Lake Huron.

Speckle Splake Spectacular

Ice Fishing for big Northern Ontario speckled & splake trout.