How to Remove Gas From a Boat Gas Tank

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With the end of boating season comes the process of laying up the boat for the winter. Your fuel tank should be stored dry, completely free of fuel. This prevents condensation in the tank from mixing with and adulterating the fuel over the off-season, a condition that fuel stabilizers don't address. Part of the process of draining the fuel tank dovetails nicely with preparing your outboard motor for winter storage.

Items you will need

  • Outboard motor flushing attachment ("earmuffs")

  • Screwdriver

  • Pliers

  • Automotive oil drain pan

Install flushing attachments ("earmuffs") on the water intakes of your motor. Attach a garden hose to the earmuffs. Turn on the hose until water is coming from around the earmuffs; this means you have an adequate water supply to run your motor.

Start your motor and run it (in neutral) until the motor starves--shuts down from lack of fuel. Shut down the motor, turn off the hose and remove the earmuffs. You have started the process of draining your fuel tank and flushed your engine.

Use a pair of pliers to disconnect the straps that hold the fuel tank in place. Disconnect the fuel line from the gas tank with a screwdriver, if it's held by a hose clamp, or pliers if it's held on by a compression clamp. Do not disconnect the fuel line from the motor. If there is any fuel left in the line, drain it into a drain pan.

Open the fuel filler cap on the fuel tank. If the tank is vented, open the vent. Turn the tank over the drain pan and allow any remaining fuel to drain through the fuel filler. Turn the tank right-side up and allow it to stand for one hour.

Dispose of the drained fuel in a manner approved by your local government.


  • Before running your outboard ashore, remove the prop to prevent propeller-related accidents, which can be serious or fatal. Gasoline vapors ignite at minus 40 degrees F and represent a fire hazard. Allow no open flame or smoking in the immediate area.


  • You can store fuel in your tank over the off-season, but you must fill the tank after the last use of the season and add fuel stabilizer to the tank, according to the instructions on the fuel stabilizer container.