How to Adjust the Carburetor on a Ryobi String Trimmer

Ryobi is a manufacturer of gasoline powered lawn equipment, including several models of string trimmers. If your trimmer's engine begins acting balky and refuses to idle correctly, the carburetor may need to be adjusted. Using one simple hand tool, the job will most likely require only a few minutes of your time.

Engine Stalls or Idles Too Low

• 1

  Start your trimmer and let the engine run at a high idle for a minute or two, allowing it to warm to normal operating temperature.

• 2

  Release the throttle trigger to determine if it will idle normally. If the engine stops, retrieve your small screwdriver and prepare to adjust the carburetor.

• 3

  Insert the screwdriver into the small hole in the air cleaner/muffler cover.

• 4

  Turn the idle adjustment screw one-eighth turn in a clockwise direction.

• 5

  Restart the engine. If it idles smoothly and does not stall, you are finished. If it continues stalling, repeat the process by turning the idle adjustment screw another one-eighth turn and restarting the engine once again. Continue alternately adjusting the idle screw and restarting the engine until it idles properly.

Reducing Engine Idle Speed

• 1

  Start your trimmer and let the engine run at a high idle for a minute or two, allowing it to warm to normal operating temperature.

• 2

  Release the throttle trigger to determine if the engine will idle normally. If it idles at too high of a speed, use your screwdriver to reduce the idle.

• 3

  Insert the screwdriver into the small hole in the air cleaner/muffler cover. With the engine still running, turn the idle adjustment screw one-eighth turn in a counterclockwise direction. Continue making one-eighth turn counterclockwise adjustments to the idle screw until the engine idle is properly reduced.