How To Winterize Your Boat (and Motor, and Trailer)

Dec. 23 2021 News By Ina Marine

It’s December, and that means we need talk ‘How to Winterize Your Boat’.

If you’re an experienced boater, you know why this is important (something about having to replace an outboard motor in March?). And if you’re new to boating, we suggest you take note.

Winterizing your boat is how you protect your beloved aluminum vessel from Mother Nature when the mercury dips. That’s all the more important here on the west coast, where we don’t get Winnipeg temperatures, but our damp winters can do more than a wallop of damage if you don’t take these basic precautions.
So, how do you winterize your boat?

#1 – Winterize Your Boat

Let’s step back for a moment and look at the big picture. Look at your boat, trailer and motor. We’re going to winterize all three of them, and we’ll do it now.

Start with a cleaning. Get right in there – wash away last season’s dirt, grit and the remains of all that fun you had last summer (don’t worry, do this right and you’ll have more fun again next year!). Clean your boat from bow to stern, and do the same with your trailer. Got questions about how to clean your boat? Give us a call and we’ll help you out.

Now, is your boat sparkling? Super – now remove your drain plug and raise your bow so it’s higher than your stern. This helps any remaining water trickle out, so it doesn’t freeze.

Once that’s done, remove all items from your boat. Yup, everything – the seats, life jackets, trolling motors, electronics – the whole works. Store your electronics inside, and be sure to disconnect any batteries, clean the terminals with a combination of baking soda and water and grease when they’re dry.

While you’re at it, make an inventory of any gear or equipment that should be fixed or replaced.

#2 – Winterize Your Outboard Motor

This is going to take a little work, but do this now and your motor will thank you later. First, fill up your gas tanks. This reduces moisture build-up over winter, which is definitely a good thing. Check your hoses, bulbs and connectors too. Any leaks or deterioration? Replace as required.

Next, change the fuel filter and water separator. Add a fuel stabilizer to your gas tank to make your motor a happy one when you rev it up next spring.

Once that’s done, attach a motor flusher to your garden hose. Slide it over the water intake vents – they’re on the lower unit of the motor. Now turn the water on, start the motor and let it idle for about 15 minutes. While it’s running, spray a fogging agent through the carburetors until you see smoke coming from the exhaust and the motor cuts out. This spreads oil throughout the motor, which reduces spread of moisture over winter – a common trend you’ll want to pursue as you winterize your boat.

If you have a four-stroke motor, be sure to remove the spark plugs and apply a fogging agent to the cylinder walls, spark plugs and pistons.

Spin the flywheel a few times by hand too. Find it via your owner’s manual, or give us a call here at Ina Marine – we know a few things about outboard motors!

Think about replacing your spark plugs in spring as well, and be sure to gap them correctly when you do.

Now, coat the engine body with a silicone anti-corrosion spray. This, you guessed it, helps reduce moisture spread throughout the motor.

With that done, drain the lower unit of oil, and watch if it has a cloudy or milky appearance. If it does, there may be an issue with your seal. You may want a marine mechanic for that – again, contact us at Ina Marine, we can help with that. If the oil is fine, pump fresh oil into the lower screw hole until it seeps out of the upper screw hole. Replace the top screw first, lower second.

Finally, remove the propeller and look for weeds, fishing line and anything that might have entangled around the shaft. You’ll need to replace any seals that are damaged. And now that you’ve got the propeller off, look for cracks, breaks or bends. If much wear is evident, you’ll need to rebuild or replace it. Now coat the shaft with lube and replace the propeller.

#3 – Winterize Your Trailer

If you’ve got a boat trailer, you’ll want to winterize that too. Here’s how that works: check your lights for water and dry them as required. Remove the bulbs and spray the sockets with a little moisture repellent. Check your seals too, and replace your light covers while you’re at it.

Take a closer look at your wiring harness, trailer bunks and winch. Apply a small amount of petroleum jelly on the connectors. Now cap them – they’re good for the winter.

Hoist each wheel in the air and spin every one. Do you hear grating? Are the tires not running on their own? You may have a bearing problem. Give us a call. Do things look good? Pull the wheel assembly, then clean and re-pack it with fresh grease. When the wheels are back on, add a little more grease through the bearing protectors.

Don’t forget to check your trailer tires for wear and proper inflation too.

When you winterize your boat, we generally recommend that our customers remove the wheels and keep the tires inside during the colder months. This keeps them out of the elements and can prevent ‘flat spots’ that can develop when a trailer sits for months.

Block your trailer first, before you do this (no rampant boat trailers in the road please!).

Finally, jack the trailer up by the axles while you keep the springs in the load position. That’s how you store a boat trailer for winter – and that’s how you winterize your boat, motor, trailer and these essential components to your boating experience!

Ina Marine Can Help You Winterize Your Boat

This may seem like a lot of work, and truth be told, not everyone may be keen to put in this kind of elbow grease. But trust us when we say this: you’ll be glad you did – and your boat, trailer and motor will likely last longer for your efforts.

Reach out to us if you have any questions. With over 40 years’ experience in boating the waters of the Pacific Northwest, we’ve winterized a boat or too. Want some helpful suggestions or for us to do it for you? That’s why we’re here, and we’re always glad to lend a hand.

Until next time!