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

Four Fantastic Ontario Musky Waters

Discover 4 hotspots that any musky angler must add to their bucket list.

Top Flies for Northern Pike

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

How To Stay Really Warm This Winter: The Second Edition

Must-wear items for staying warm—so you can enjoy your day on the ice!

Miles Bay Camp

Secluded fishing attracts anglers to Miles Bay on Lake of the Woods

Cat Island Lodge

Fly-in fishing for walleye and lake trout

Kicking It Old School

Dusting off the tin boat to fish less accessible waters

First Class Fishing Vacations

Northern Ontario boasts hundreds of lakes, rivers and streams.

Steelhead and Salmon of Northern Ontario

Ontario's north is home to tributaries of Lake Superior and Lake Huron—and many species of salmon and steelhead

Smallmouth Bass: Lightweight Champ

Learn about easy-to-access bass meccas as well as bucket-list hard to get to destinations.

Level Up Your Fly Fishing Game

Embrace the art of fly fishing with these 5 easy tips from a seasoned angler.

Brennan Harbour Resort

The place you always want to go back to in Ontario's Algoma Country

Mashkinonje Lodge

During our short stay we caught and released several trophy smallies over five-pounds.

Sniping For Lake Trout

If you love fishing for Lake Trout in Ontario, you’d be wise to hone your sharpshooting skills.

Out On A Ledge In Ontario

Bluffs are One of the Best Places to Catch Fish

The Best of Both Worlds

From spring right through to late fall there are species that you can target close to the home base in the Spanish River

Pot of Golden Walleye

Fishing at Whitefish Lodge in Ontario's Algoma Country

Smallmouth At Lakair Lodge

Discover wildlife, scenery, and epic fishing Ontario's fifth largest freshwater lake

Walleye Sunsets

Walleye Fishing on Lake Nipissing.

Terrestrial Flies for Brook Trout

These fish feed like crazy and look for opportunities for a big protein meal.

Outpost Walleye in Brook Trout Country

This is an outpost fishing adventure you won't want to miss.