The Shindaiwa Company manufactures a variety of two-cycle power lawn tools. Two-cycle engine's run on a mixture of oil and gasoline; this is used as not only fuel but also lubricant for the internal components. When the starts to run to lean or to rich, it will cause erratic performance. Adjusting the carburetor will get the engine running back to the optimal performance. This procedure should take less than 30 minutes to complete.
Set the trimmer on a hard, flat surface. Ensure the cutter head is installed on the end of the trimmer, and the cutting nylon is cut to the correct length.
Locate the carburetor on the right side of the engine directly under the air filter. There are three adjustment screws on the side of the carburetor, they are marked with an "L" for low speed adjustment, an "H" for high-speed adjustment and an "I" for idle adjustment.
Turn the "L" screw clockwise until it gently seats with the flathead screwdriver. Turn the "L" screw counterclockwise 1-1/8 of a turn.
Turn the "H" screw clockwise until it gently seats. Turn the "H" screw counterclockwise 1-1/8 of a turn. Start the engine and allow warming up for 2 to 3 minutes.
Turn the "I" screw clockwise until the trimmer head begins to turn, and then slowly turn the screw counterclockwise until the cutting head stops.