If you’re an owner of an outboard boat motor and haven’t as yet prepared it for winter storage, don’t wait until the snow flies to do so. The folks at Yamaha offer these winterizing tips that you can do yourself to save the cost of taking it to a boat dealer.
For starters, Yamaha recommends draining any water out of the engine as any water will turn to ice, expand, and likely break something like the powerhead. In case you’ve never attempted this before, simply trim the motor all the way in toward the transom and any water remaining inside will come out.
Next, treat the fuel left in the tank. The ethanol-mix fuel in the tank will be setting there and trying to separate all winter and the water that comes out will sink to the bottom of the tank where the fuel pickup is located. That water will be the first thing that will go into your fuel system when trying to start the engine in spring; The easy way to avoid this is to put fuel stabilizer in the tank like is done in lawn mowers, weed wackers and leaf blowers. The stabilizer, says Yamaha, prevents the fuel from separating so no water goes into the cylinders.
Batteries, if left in the boat, do not like cold weather. If the boat battery gets fully discharged in winter, it can freeze and could crack the housing. If your boat is stored outside, it’s recommended to remove the battery and store it inside where it can’t freeze. Yamaha also suggests putting a trickle charger on it over the winter as it can keep the battery at or near full charge so it will be ready to start the motor in spring.
It’s also a good idea to change your four-stroke outboard oil to get rid of dirt and acids that may have accumulated inside. There are videos on motor company websites showing how to do this job. It’s far from a fun job as you’ll need a collector pan, funnel and filter. Once the oil is drained, the next problem is what to do with the old oil. If there’s not a recycling place that will take the oil, you may want to ask your local service station where you may take your vehicle for a lube and oil change. Or take it to the dealer where you bought the car or truck and ask the service manager.
This may be a good time to also to change the lower unit gear oil. Another unpleasant task. Again, check the website to see how it’s done. West Marine also has a video on this task.
Nick Hromiak has been an outdoors and automotive writer for over 30 years. He's been published in numerous national and state-wide outdoor magazines and newspapers.