Stihl MS 201 Instruction Manual - Page 43

Standard setting B H L 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 N Carry out the standard setting. N Start and warm up the engine. Engine stops while idling N Turn the idle speed screw (LA) clockwise until the chain begins to run - then back it off 1 1/2 turns. 0012BA040 KN 0011BA016 KN Saw chain runs while engine is idling N Run engine for 30 seconds at idle speed before making adjustment. N Turn the idle speed screw (LA) counterclockwise until the chain stops running - then turn it another 1 1/2 turns in the same direction. WARNING If the chain continues moving when the engine is idling, have your saw checked and repaired by your servicing dealer. Erratic idling behavior, poor acceleration (even though standard setting of low speed screw is correct) N Run engine for 30 seconds at idle speed before making adjustment. Idle setting is too lean N Turn the low speed screw (L) carefully counterclockwise, no further than stop, 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: English 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. MS 201, MS 201 C 41