Place the blower on a flat workbench. Locate the three adjustment screws found on the side of the carburetor, just below the air filter. There are two screws side by side. They are marked "H" for the full throttle adjustment and "L" for the low speed adjustment. Underneath the "H" and "L" screw is an idle screw marked "C."
Turn the "L" screw clockwise until the screw seats with the screwdriver. Turn the screw back counterclockwise one full turn. Start the engine and let idle for two minutes. Turn the "L" screw counterclockwise by 1/8 of a turn until the engine runs smoothly. Shut off the engine.
Turn the "H" screw clockwise until the screw seats. Turn the screw back out counterclockwise one full turn. Start the engine and advance the throttle to the full throttle position. Turn the "H" screw counterclockwise by 1/8 of a turn until the engine runs smoothly in the full throttle position.
Rev the engine. If the engine is sluggish to get to the full throttle position, turn the "C" idle screw clockwise 1/8 of a turn and rev the engine again. Repeat this step until the blower revs smoothly to the full throttle position.