Winterize Your Boat

It’s time to pull in the docks, rafts, lifts, and boats for another season. But there is more to it than just taking boats out of the water. Winterizing a boat and motor is the most important maintenance a boat owner can perform to help ensure safe boating next spring.

Whether you choose to do it yourself or have your marina or storage facility do it for you, winterizing is the best way to prepare your boat for the season to come. Regardless of where your boat is stored (inside or outside), much care is needed to protect your boat engine.

The following are some basic steps to winterize your marine engine and equipment:

  • Fill the fuel tanks and add the appropriate amount of stabilizer. Run the engine long enough to get treated gas into the fuel line and engine. Left untreated over the winter, gasoline deteriorates into varnish and gum, making starting difficult.
  • Flush the cooling system. (Flushing kits are available from boat dealers.) Also remove block plugs and drain all the water from inboard and inboard outdrive engines. This cleans out accumulated sediment and rust flakes. Pump in anti-freeze to avoid trapped ice pockets. Use an environmentally safe product to avoid contaminating the marine environment.
  • Fog the engine with oil to prevent rust. Available in bulk or aerosol cans, fogging oil is formulated to stick to the cylinders and not slide down the walls. Follow the instructions that come with the product making sure to spray some of the oil into the cylinders through the spark plug holes once the engine has cooled down. Check the spark plugs and replace them as necessary.
  • Replace the oil and oil filter on inboard and inboard outdrive engines. Be sure to dispose of the used oil at an authorized recycling center.
  • Change the lower unit gear case lubricant on outboards and inboard/outdrive engines. Even a little water trapped in the gear case can cause damage, especially if allowed to freeze.
  • Check the props for nicks. Even slight damage can hinder performance. Worse yet, blade damage can cause vibration, damaging other engine parts and the drive system. Some damaged props can be repaired by marine dealers for a fraction of the cost of a new one.
  • Store outboards in an upright position. Consider having the water pump impeller replaced every two or three years. The rubber legs can get stiff, reducing water circulation, or they may break off, eliminating coolant flow completely.
  • Spray a moisture displacing lubricant such as a silicone product onto electrical terminals and the fuse panel. Read the label to make sure the spray is safe for use on electrical components.
  • Inspect steering systems, including tiller steering friction fittings on outboards. Tighten them if they’re loose.
  • Clean the backfire flame arrester on inboard engines with carburetor cleaner.
  • Clean boats inside and out and cover when stored, even indoors. Allow for air circulation under the cover to prevent mildew.
  • Drain water from the bilges and leave the transom drain plug out. It’s a good idea to place a reminder note in a conspicuous place to avoid embarrassment at the boat ramp next spring.
  • Hang life jackets up where they can air out.
  • Examine trailer tires and grease the wheel bearings, replacing them as necessary. Check bulbs and electrical contacts on the plugs as well as sockets where the bulbs screw in. Spray contacts with a moisture displacing lubricant and wrap electrical tape around the plugs to keep them dry.
  • Put the trailer on blocks and remove the tires to prolong rubber life and hinder boat thieves.
  • Check the owners manual for tips that are particular to your own brand of boat, engine and trailer.

For boaters who aren’t comfortable doing their own maintenance, all the procedures may be performed by a qualified marine technician at your local boat dealer. Taking a little time in the fall to get your boat and motor ready for winter means that you can be one of the first boaters out on the water next spring.