Stihl BG 46 Instruction Manual - Page 18

Adjusting the Carburetor (With idle speed screw LD) - LD + The carburetor is set at the factory to provide an optimum fuel-air mixture under all operating conditions. 295BA022 KN english / USA Catalytic Converter Standard setting : Check the air filter and replace if necessary. : Start and warm up the engine. : Carefully screw the idle speed screw (LD) down onto its seat counterclockwise (left-hand thread). Then open it two full turns clockwise (standard setting). Engine stops when engine is idling: Carry out standard setting (open the LD screw two full turns) : Rotate idle speed screw (LD) about one half turn clockwise until the engine runs smoothly. Units with a catalytic converter* may only be operated with unleaded gasoline and STIHL two cycle engine oil or equivalent quality two cycle engine oils in a mix ratio of 50:1 (see chapter "Fuel"). The catalylic converter in the muffler reduces noxious emissions in the exhaust gas. Correct adjustment of the carburetor (if adjustable) and observancen of the specified mix ratio of gasoline and two cycle engine oil are essential to minimize harmful exhaust emissions and ensure a long catalyst service life. Erratic idling behavior, poor acceleration: Carry out standard setting (open the LD screw two full turns) : Rotate idle speed screw (LD) about one half turn counterclockwise. BG 46 * see "Guide to Using this Manual" 17