How to Unstick a Float Valve in an Outboard Engine

by Timothy Burns
2-cycle fuel used in boat motors easily can clog a carburetor float valve.

2-cycle fuel used in boat motors easily can clog a carburetor float valve.

A float valve controls the gas flow into, and out of, a traditional carburetor. Before motors were engineered with electronic fuel injection, this style of traditional carburetor was found on most motors. Car engines, outboard boats and even lawnmowers used the same style carburetor system to control the mixture of gas and air that power the motor. In 2-cycle outboard motors, the float valve occasionally becomes clogged with fuel deposits.

1. Thoroughly study the motor manual. Identify the connectors that hold the metal cover over the motor. Also identity the carburetor and fuel line connection.

2. Remove the plastic / metal shroud from around the top of the boat motor. This metal cover protects the engine's serviceable parts. In most cases, it must be removed to gain access to the motor's carburetor.

3. Disconnect the fuel line from the engine. This will give you direct access into the carburetor's fuel chamber.

4. Spray a liberal amount of carburetor cleaner into the carburetor through the fuel line orifice. Allow a few minutes to pass, and turn the motor over a few times. Repeat the process.

5. Reapply the fuel line, and try starting the motor. For float valves that are slightly dirty, this simple step could fix the problem.

6. If the motor still isn't responding properly, remove the fuel line again. Spray carburetor cleaner into the orifice again, and this time, turn the motor over as you spray the cleaner. The motor will not start, but as the carburetor cleaner is sucked through the system, it might thoroughly clean the float valve. Reinstall the fuel line, and try the motor again.

Items you will need

  • Outboard boat motor
  • Moat motor manual (recommended)
  • Mechanic's hand tools, including socket wrench set, Allen wrench set, screwdrivers, pliers, etc.
  • Spray carburetor cleaner
  • Clean plastic parts container
  • Clean rags

About the Author

Since 2003, Timothy Burns' writing has appeared in magazines, management and leadership papers. He has contributed to nationally published books and he leads the Word Weavers of West Michigan writers' group. Burns wrote "Forged in the Fire" in 2004, and has published numerous articles online. As a trained conference speaker, Burns speaks nationally on the art, science and inspiration of freelance writing.

Photo Credits

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