How to Adjust the Idle Speed on a Homelite Weed Trimmer

Find the idle-speed adjustment screw on your Homelite weed trimmer. The screw is between the side of the engine and the air filter cover. Some Homelite weed trimmers also have visible high-speed and low-speed adjustment screws. The idle-speed screw has a "T" stamp next to it to distinguish it from the other screws.

Start the Homelite trimmer, and allow the engine to warm up for five minutes. This gives time for the engine to reach operating temperature.

Squeeze and release the power trigger on the trimmer. This will bring the trimmer down to idle. Turn the idle-speed adjustment screw until the engine runs smoothly without the trimmer head turning. Turn the screw clockwise with a Phillips-head screwdriver to increase the speed, or counterclockwise to decrease the speed.

Turn the "L" screw clockwise with the screwdriver until the head begins to turn, if you have the visible high-speed and low-speed screws. Once the trimmer head begins to rotate, turn the "L" screw counterclockwise 1/8 turn.

Squeeze the power trigger, and turn the "H" speed screw clockwise until smoke begins to come from the muffler. Once the muffler emits smoke, turn the "H" screw counterclockwise ¼ turn.