Stihl GS 461 Rock Boss174 Product Instruction Manual - Page 30

English N Turn high speed screw (H) counterclockwise as far as stop (no more than 3/4 turn). N Turn the low speed screw (L) clockwise as far as stop, then turn it back 1/4 turn. Adjusting Idle Speed 3443BA001 KN Engine stops while idling or chain runs while engine is idling N Turn the idle speed screw (LA) clockwise as far as stop or until the chain begins to run - then turn the screw back 1 1/2 turns. WARNING If the chain continues moving when the engine is idling, have your machine checked and repaired by your servicing dealer. Erratic idling behavior, poor acceleration (even though low speed screw is open 1/4 turn) N Carry out the standard setting. N Warm up the engine. N Turn high speed screw (H) slightly clockwise (leaner) - no further than stop. NOTICE After returning from high altitude, reset the carburetor to the standard setting. If the setting is too lean there is a risk of engine damage due to insufficient lubrication and overheating. 3443BA003 KN Before starting, open the shut-off cock fully so that water flows to the diamond abrasive chain - never allow chain to run dry. N Carry out the standard setting. N Start and warm up the engine. 3443BA002 KN Idle setting is too lean N Turn the low speed screw (L) counterclockwise until the engine runs and accelerates smoothly. It is usually necessary to change the setting of the idle speed screw (LA) after every correction to the low speed screw (L). Fine Tuning for Operation at High Altitude A slight correction of the setting may be necessary if engine does not run satisfactorily: 28 GS 461