Stihl HT 103 Product Instruction Manual - Page 34

0000-GXX-0495-A0 0000-GXX-0486-A0 0000-GXX 0537-A0 English Adjusting the Carburetor The carburetor has been set at the factory to provide an optimum fuel-air mixture under most operating conditions. Adjusting Idle Speed Engine stops while idling N Warm up the engine for about 3 minutes. N Turn the idle speed screw (LA) slowly clockwise until the engine runs smoothly - the saw chain must not rotate. Chain rotates when engine is idling N Turn the idle speed screw (LA) counterclockwise until the chain stops running and then turn the screw another 1/2 to 3/4 turn in the same direction. Spark Arresting Screen in Muffler N If the engine is down on power, check the spark arresting screen in the muffler. N Wait for the muffler to cool down. 4 5 N Take out the screw (4). N Lift the spark arresting screen (5) and pull it out. N Clean the spark arresting screen (5). If the screen is damaged or heavily carbonized, install a new one. N Refit the spark arresting screen (5). N Insert the screw (4) and tighten it down firmly. Spark Plug If the engine is down on power, difficult to start or runs poorly at idling speed, first check the spark plug. Install a new spark plug after approx. 100 operating hours or earlier if the electrodes are badly eroded/corroded. The wrong fuel mix (too much engine oil in the gasoline), a dirty air filter and unfavorable running conditions (mostly at part throttle etc.) affect the condition of the spark plug. These factors cause deposits to form on the insulator nose which may degrade performance. Removing the Spark Plug 1 2 3 N Remove the cover (1). N Pull off the spark plug boot (2). N Unscrew the spark plug (3). WARNING If the chain continues moving when the engine is idling, have your power tool checked and repaired by your servicing dealer. 32 HT 102, HT 103, HT 132, HT 133