Stihl GS 461 Rock Boss174 Product Instruction Manual - Page 31

English 2411BA032 KN Spark Arresting Screen in Muffler In some countries, the muffler is fitted with a spark arresting screen. N If engine performance deteriorates, check the spark arresting screen in the muffler N Let the muffler cool down 1 N Remove four screws N Remove exhaust casing (1) of the muffler 3 2 N Bend back the retaining lugs (2) N Pull out spark arresting screen (3) N Clean the dirty spark arresting screen, replace if damaged or heavily carbonized N Refit the spark arresting screen in reverse order of steps 3443BA010 KN 3443BA009 KN Spark Plug If engine is down on power, difficult to start or runs poorly at idling speed, first check the spark plug. Fit a new spark plug after approx. 100 operating hours or earlier if the electrodes are badly eroded. 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 result in trouble in operation. Remove the spark plug N Remove coarse dirt from the machine N Turn screw plug above the rear handle in the direction of the arrow and remove filter cover - screw plug is secured in the filter cover 2411BA030 KN 1 2 N Lift the air baffle (1) up and off N Unplug spark plug boot (2) N Unscrew spark plug Checking the Spark Plug A N Clean dirty spark plug. N Check electrode gap (A) and readjust if necessary - see "Specifications." N Use only resistor type spark plugs of the approved range. Rectify problems that 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 GS 461 29