Fuel Tank (3 Minutes)
Gasoline, unfortunately, doesn't like to be left alone any more than your engine and, given the right conditions, gasoline turns to a sticky, varnish-like substance. Bad gasoline can gum up your fuel injectors or carb, cause the valves to stick, and even plug the fuel lines.
You need to protect your fuel system from the winter elements, and you'll have a choice of draining your tank or filling your tank. If you store your boat in a boatyard or commercial storage area, check their rules because they may require you to drain the fuel out of your tank before storage. If so, this is a task for the pros at your local dealership.
If you're storing your boat at home or somewhere that doesn't require draining the tank, you should top off the tank to prevent condensation from forming in an empty or half-empty tank. That condensation becomes water, which can create endless problems when you try to start your boat in the spring.
To keep your gas fresh during the winter, add a fuel stabilizer (EZ-to-Store EZ-to-Start, for example) by pouring the proper amount into your fuel tank.
When you're finished, make sure the gas filler cap is screwed firmly in place and tape over the fuel vent to protect it from moisture. One skipper, who stored his boat in his yard, found his tank full of water which had entered the fuel vent when his lawn sprinklers shot water upwards under the vent.
Remove Batteries (6 minutes)
To remove the batteries, unbolt the battery terminals from the posts and, if the cables aren't marked with (+) and (-) or red and black colors, you should tag the positive cable with a piece of tape so you won't make a shocking (bad pun!) mistake when reconnecting the batteries in the spring.
If your battery has a whitish coating on the top, make a baking soda paste with water and clean the case, followed by thorough rinsing. Use the same method to get rid of any build-up on the battery cable clamps, too. Lightly smear the battery terminals with petroleum jelly for winter protection.
Your batteries should be stored in a warm and dry place such as your garage, and, since putting them on a concrete slab or dirt floor can drain them quickly, insulate them on pieces of wood.
At home, you should keep the batteries charged during the winter. If you have a modern battery charger that automatically senses the proper trickle charge, you can leave that connected continually. If your battery charger is the "off-on" variety, top off the battery monthly but don't just leave the charger on, because it can overheat and ruin the battery.