Launch Slideshow

Do-it-yourself carburetor cleaning

Do-it-yourself carburetor cleaning

  • Fuel left inside an engine for longer than 30 days begins gumming up, forming a varnish-like material that clogs up the small jets and ports in the carburetor. To clean the bowl, use carb cleaner and scrape out the varnish.

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    Fuel left inside an engine for longer than 30 days begins gumming up, forming a varnish-like material that clogs up the small jets and ports in the carburetor. To clean the bowl, use carb cleaner and scrape out the varnish.

    600

    Subaru Industrial Power Equipment

    Fuel left inside an engine for longer than 30 days begins gumming up, forming a varnish-like material that clogs up the small jets and ports in the carburetor. To clean the bowl, use carb cleaner and scrape out the varnish.
  • When cleaning the carburetor, first drain the carburetor bowl by removing the drain screw.

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    When cleaning the carburetor, first drain the carburetor bowl by removing the drain screw.

    600

    Subaru Industrial Power Equipment

    When cleaning the carburetor, first drain the carburetor bowl by removing the drain screw.
  • Often its easier to completely remove the carburetor for cleaning. Start by removing the choke lever. Unlatch the governor link and the tensioning spring with needle nose pliers.

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    Often its easier to completely remove the carburetor for cleaning. Start by removing the choke lever. Unlatch the governor link and the tensioning spring with needle nose pliers.

    600

    Subaru Industrial Power Equipment

    Often it’s easier to completely remove the carburetor for cleaning. Start by removing the choke lever. Unlatch the governor link and the tensioning spring with needle nose pliers.
  • Check the gasket on the inside of the air filter assembly to be sure its in good shape.

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    Check the gasket on the inside of the air filter assembly to be sure its in good shape.

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    Subarua Industrial Power Equipment

    Check the gasket on the inside of the air filter assembly to be sure it’s in good shape.
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    Check the gasket on the inside of the air filter assembly to be sure it’s in good shape.

  • Remove the hinge pin from the float. With the float comes the needle, which should be cleaned.

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    Remove the hinge pin from the float. With the float comes the needle, which should be cleaned.

    600

    Subaru Indstrial Power Equipment

    Remove the hinge pin from the float. With the float comes the needle, which should be cleaned.
  • After lifting the float, the main jet in the carburetor is visible. The jets passage is where fuel flows through the carburetor into the combustion chambers. To inspect, remove the jet with a flat blade screwdriver.

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    After lifting the float, the main jet in the carburetor is visible. The jets passage is where fuel flows through the carburetor into the combustion chambers. To inspect, remove the jet with a flat blade screwdriver.

    600

    Subaru Industrial Power Equipment

    After lifting the float, the main jet in the carburetor is visible. The jet’s passage is where fuel flows through the carburetor into the combustion chambers. To inspect, remove the jet with a flat blade screwdriver.
  • To open the passage of the jet, spray carb cleaner on it and use one bristle of a wire brush to insert and clear out any particles or gummed fuel. Be careful not to make it any larger than its original size.

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    To open the passage of the jet, spray carb cleaner on it and use one bristle of a wire brush to insert and clear out any particles or gummed fuel. Be careful not to make it any larger than its original size.

    600

    Subaru Industrial Power Equipment

    To open the passage of the jet, spray carb cleaner on it and use one bristle of a wire brush to insert and clear out any particles or gummed fuel. Be careful not to make it any larger than its original size.
  • The limit cap is part of the tamper-proof system required by the EPA. It is a non-serviceable part, so handle it with extra care.

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    The limit cap is part of the tamper-proof system required by the EPA. It is a non-serviceable part, so handle it with extra care.

    600

    Subaru Industrial Power Equipment

    The limit cap is part of the tamper-proof system required by the EPA. It is a non-serviceable part, so handle it with extra care.
  • Clean the main nozzle passage until its free of grime. Be sure the holes on the sides are open and clean as well.

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    Clean the main nozzle passage until its free of grime. Be sure the holes on the sides are open and clean as well.

    600

    Subaru Industrial Power Equipment

    Clean the main nozzle passage until it’s free of grime. Be sure the holes on the sides are open and clean as well.
  • Check to see the gasket (either flat or O-ring) that seals the carburetor bowl to the carburetor body is in position and not torn or warped.

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    Check to see the gasket (either flat or O-ring) that seals the carburetor bowl to the carburetor body is in position and not torn or warped.

    600

    Subaru Industrial Power Equipment

    Check to see the gasket (either flat or O-ring) that seals the carburetor bowl to the carburetor body is in position and not torn or warped.

Digging deeper

The engine should start up and perform normally after cleaning the carburetor. If it does not, the carburetor may need to be removed from the engine for more extensive cleaning. If you must remove and clean the entire carburetor, consult the manufacturer’s service manual.

As you begin to take the air filter assembly and carburetor off, take photos of the linkage to remind yourself of how it looks fully assembled.

NOTE: The limit cap for the idle mixture screw is on the top of the carburetor. It’s part of the tamper-proof system required by the EPA and it is a non-serviceable part. If it breaks, you must replace the entire carburetor.

Prevention

Determine how long will the engine be stagnant. A high-quality fuel stabilizer will work for any engine that will sit idle from 30 days to a year. In these cases, mix the proper ratio recommended by the fuel stabilizer manufacturer. Fill the tank as full as possible, since air increases the potential for condensation and corrosion. Once you’ve added fuel stabilizer to the gas tank, run the engine about 15 minutes, long enough for the fuel to cycle into the carburetor bowl.

Manufacturers recommend completely draining the gas if the engine will not be used for longer than a year. Rather than letting a generator sit with a half tank of fuel until the next time it’s needed, twist the carburetor drain screw and drain the fuel. Pull the spark plug and spray some fogging oil on it. Pull the rope a few times, then place the spark plug back in and store the engine.

You may opt for a combination of these approaches: Leave the fuel with stabilizer in the main fuel tank, then turn off the fuel valve and drain the fuel from the carburetor or run it until it’s completely dry and the engine shuts off. That way the carburetor bowl has no fuel in it, but you still have fuel in the tank.

Prevent no-starts and engine hunts by taking care of your carburetor issues before more serious problems arise.

Dale Gabrielse handles OEM sales and marketing support for Subaru Industrial Power Equipment. Visit http://robinamerica.com.