How to Winterize Your Boat's Outboard Motor

How to Winterize Your Boat's Outboard Motor
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Protection of the outboard motor during the cold seasons is important not only for winterzing and freeze protection. It’s also an important part of your yearly preventive maintenance. That said, the cost of winterizing your outboard motor is certainly less than that of any damage during the winter.

The first step of winterizing your motor is to buy all required items according to the information provided in the owner’s manual.The general steps involved include first removing any salt from the motor. Then it’s time to protect it from corrosion; you will need to use fuel conditioner and rush-preventive oil for this job. Further, you should follow some steps to lubricate the motor and to protect the cowling of the motor. The final step is to store the motor in the right place.

A brief description of these steps follows:

How to remove salt from motor

If your boat has operated in saltwater, a freshwater flush for your motor is in order. As always, the owner’s manual should be consulted in case plugs need to be removed. The basic steps involve:

  • Attach the flush unit to the cooling system of the motor. This might include a specially-manufactured plug, but many engines have permanently mounted flush adapters than can take a garden hose.
  • If using a free-standing flush unit, a coupling should also be used at the flush unit end.
  • After attaching the unit properly, run the motor for several minutes. This will remove any salt deposits present in the motor.

How to use fuel conditioner

This process should be done when you use the motor for the last time of the season.

  • Add one ounce of fuel conditioner in the fuel tank for each gallon of fuel.
  • Run the motor for approximately 5 minutes. After this, turn off the fuel.
  • It is very important to run the motor so that to ensure that the fuel conditioner has reached the carburetor and, in the case of a two-stroke engine, the internal engine components.

How to use rust-preventive oil

  • Exhaust the fuel from the carburetor.
  • Disconnect the spark plug wires.
  • Remove the cowling.
  • After this, remove the spark plug with the help of wrench.
  • Insert a small amount of rust-preventive oil into all cylinders, one by one.
  • Spread oil throughout the cylinder by moving the flywheel slowly up to the top of the motor.
  • Fix the spark plugs at the right place; there is no need to fix the spark plug wires.

How to lubricate your motor

  • Open the fill plugs present on the top and bottom of the motor.
  • Take the lubricant into a container.
  • Fix a nozzle into the bottom fill hole to replace the lubricant.
  • It is also important to spray the lubricant into the gear case.
  • Stop inserting lubricant when it starts to come out by top fill hole.
  • Fix the top plug.
  • Remove the nozzle and fix the bottom plug at the right place.

How to protect the cowling

  • Restore bad spots using matching paint. You should use a touch-up kit, which is appropriate for you motor, for this job.
  • Use car wax for coating the cowling.
  • Rub the cowling using a cloth dipped in oil to make a light coat.
  • Tighten loose screws, nuts, and bolts.
  • Replace missing nuts, bolts, and any other hardware.
  • Make a coat of rust-preventive oil throughout the surface of cowling using a soft cloth.
  • Fix the cowling in its place correctly.

How to store the outboard motor

  • Store the motor in a dry and dust free place.
  • Cover the motor with a sheet.
  • Remove the battery of the motor, and place it on a wood block.


  • You should use all required things such as freshwater flush unit, fuel conditioner, rust-preventive oil, car wax, lubricant etc. of the brand or company given in the manual.
  • When you are removing any part, keep the assembly order of the parts your mind. It will help you during replacing.
  • The case of the battery must be cleaned properly, and water in the cells must be at the correct level.
  • If you find yourself uncomfortable with this job, then it is better to use the service of boat companies. Many boat dealers also provide this service.


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