Stihl MS 192 C-E Product Instruction Manual - Page 39

Engine Management Adjusting the Carburetor English 151BA018 KN Exhaust emissions are controlled by the design of the fundamental engine parameters and components (e.g. carburation, ignition, timing and valve or port timing) without the addition of any major hardware. General information The carburetor comes from the factory with a standard setting. This setting provides an optimum fuel-air mixture under most operating conditions. With this carburetor it is only possible to adjust the high speed screw within fine limits. If the setting is too lean there is a risk of engine damage due to insufficient lubrication and overheating. Standard setting N Shut off the engine. N Check the air filter and clean or replace if necessary. N Check the spark arresting screen (country-specific) in the muffler and clean or replace if necessary. N Turn the high speed screw (H) counterclockwise as far as stop (no more than 3/4 turn). N Carefully turn the low speed screw (L)down onto its seat (clockwise). N Open the low speed screw (L) one full turn. Adjusting idle speed Engine stops while idling N Carry out standard setting on low speed screw (L). N Turn the idle speed screw (LA) clockwise until the chain begins to run - then back it off 2 turns. Chain runs when engine is idling N Carry out standard setting on low speed screw (L). N Turn the idle speed screw (LA) counterclockwise until the chain stops running - then turn it another 2 turns in the same direction. MS 192 C 37