How to Fix Bad Gasoline in an Outboard

Bad gasoline is a generic term for gasoline that is contaminated by foreign particles, either wet or dry, and is no longer fully combustible. It might still power the outboard motor, but performance may be insufficient to keep the motor running or the motor may not run at all. Determining the problem is the first step to understanding why the gas is bad, then fixing the cause of the problem is the next step.

Things You'll Need

  • Isopropyl alcohol solution
  • Flashlight
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Instructions

    • 1

      Look inside the gas tank with a flashlight. If any globules of water are seen at the bottom of the tank, the gasoline must be dumped and refilled with fresh gas. If you see rust particles in a metal tank, the entire tank must be discarded and preferably replaced with a plastic gas can. If neither of these problems are present, go to Step 2.

    • 2

      Add an isopropyl alcohol solution to your gasoline. Use 1/2-pint per four gallons of gas, or 1/4-pint to two gallons of gas. These solutions are commonly found at gas stations, hardware stores and automotive parts and supply shops. This solution will soak up any moisture in the gasoline, which is a common cause of bad gasoline.

    • 3

      Start the motor and let it run for several minutes to allow the alcohol to make its way into the fuel lines and the engine carburetor system. If there was moisture in the gasoline, the isopropyl alcohol will cure the problem after a few minutes of run time. If there is no effect on engine performance after adding the alcohol solution, replace the bad gasoline with fresh gasoline.