Stihl FS 94 R Instruction Manual - Page 34

0208BA038 KN English Adjusting the Carburetor The carburetor of the machine has been adjusted for optimum performance and fuel efficiency in all operating states at the factory. Setting the idle speed Engine stops when idling N Turn the idle speed adjusting screw (LA) slowly clockwise until the engine runs smoothly. Cutting attachment turns when idling N Turn the idle speed adjusting screw (LA) slowly counterclockwise until the cutting attachment stops turning WARNING If the cutting attachment continues to keep rotating in idle even after adjustment, have the machine checked by a servicing dealer. 0208BA036 KN 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 2 1 N Turn screw (1) in cap (2) until cap can be removed N Lay down cap 0208BA037 KN 3 N Unplug spark plug boot (3) N Unscrew spark plug Checking the Spark Plug A N Clean dirty spark plug. N Check electrode gap (A) and readjust if necessary - see chapter "Specifications." N Use only resistor type spark plugs of the approved range. Rectify problems which have caused fouling of spark plug: - too much oil in fuel mix, - dirty air filter, - unfavorable running conditions, e.g. operating at part load. 000BA039 KN 32 STIHL FS 94 R