There comes a time when a boat fuel tank must be drained of all fuel, for a cleaning procedure or as a method to exchange old contaminated gas for a fresher blend. Boat tanks, because of constant vibration, can also fill up with rust, which can lay as sediment at the bottom of tank. Some tanks must be cleaned in order to remove all traces of water, sludge and varnish. Whatever the reason, a boat owner has a few options when it comes to draining his boat tank of fuel.
An easy procedure for removing fuel from an outboard tank requires running the motor until a substantial amount of fuel has been consumed. If the tank holds a regulation 5, 10 or 15 gallons, the next step requires removing the intake gas line, using pliers, a screwdriver or pulling the quick-release, and then pulling the tank out of the boat. The remaining fuel can then be manually emptied into a certified container. The procedure will work for a larger aluminum tank, held to the bilge by straps. After the strap bolts have been removed with a socket, the tank can be manually emptied by two persons.