Stihl HL 100 K 0 Product Instruction Manual - Page 28

English / USA Fine Tuning A slight correction of the setting of the high speed screw (H) may be necessary if engine power is not satisfactory when operating at high altitude or at sea level. Rule of Thumb : Turn the high speed screw (H) about one quarter turn for every 1000m (3300 ft) change in altitude. : Carry out the standard setting without disturbing the high speed screw (H) . : Warm up the engine for about 3 minutes. : Open the throttle wide. At high altitude : Turn the high speed screw (H) clockwise (leaner), no further than stop, until there is no noticeable increase in engine speed. At sea level : Turn the high speed screw (H) counterclockwise (richer), no further than stop, until there is no noticeable increase in engine speed. It is possible that maximum engine speed may be reached with the standard setting in each case. Adjusting 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). : Warm up the engine for about 3 minutes. Cutting blades run when engine is idling : Turn idle speed screw (LA) slowly counterclockwise until cutting blades stop running and then turn the screw about another 1/2 to 3/4 turn in the same direction Erratic idling behavior, engine stops even though setting of LA screw is correct, poor acceleration Idle setting too lean: : Turn low speed screw (L) counterclockwise, no further than stop, until the engine runs and accelerates smoothly. Erratic idling behavior Idle setting too rich: : Turn low speed screw (L) clockwise, no further than stop, until the engine runs and accelerates smoothly. Engine stops while idling : Turn idle speed screw (LA) slowly clockwise until the engine runs smoothly - the cutting blades must not run. HL 100 27