Stihl FS 55 R Product Instruction Manual - Page 35

Aadjusting Idle Speed It is usually necessary to change the setting of the idle speed screw (LA) after every correction to the low speed screw (L). N Warm up the engine. Engine stops while idling N Turn the idle speed screw (LA) slowly clockwise until the engine runs smoothly - the cutting attachment must not turn. Cutting attachment rotates when engine is idling N Turn the idle speed screw (LA) counterclockwise until the cutting attachment stops moving and then rotate the screw another 1/2 to 1 turn in the same direction. If the cutting attachment continues to run when the engine is idling, have your machine checked and repaired by your servicing dealer. Erratic idling behavior, engine stops even though setting of LA-screw has been corrected, poor acceleration Idle setting is too lean: N Idle setting is too lean: Rotate the low speed screw (L) about 1/4 turn counterclockwise until the engine runs and accelerates smoothly. Erratic idling behavior Idle setting is too rich N Rotate the low speed screw (L) about 1/4 turn clockwise until the engine runs and accelerates smoothly. Spark Plug English 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. Removing the Spark Plug N Move the stop switch to 0. 1 232BA081 KN N Pull off the spark plug boot (1). N Unscrew the spark plug. FS 55, FS 55 C, FS 55 R, FS 55 RC 33