Stihl FS 490 C-M Instruction Manual - Page 38

English Engine Management M-Tronic Winter Operation Exhaust emissions are controlled by the design of the engine and components (e.g. carburation, ignition, timing and valve or port timing). General Information The M-Tronic controls fuel feed and ignition timing electronically in all operating conditions. M-Tronic guarantees simple and fast starts. The engine is started in the Start } position irrespective of climatic conditions or engine temperature. After starting, the Start } position can be maintained until the engine runs smoothly. M-Tronic ensures optimum engine power at all times, very good acceleration and automatic adjustment to suit changing conditions. For this reason there is no need to change the carburetor setting - the carburetor has no adjusting screws. If the usual good running behavior and engine power are not reached after an extreme change in operating conditions, contact your servicing dealer for assistance. STIHL recommends that you have servicing and repair work carried out exclusively by an authorized STIHL servicing dealer. At temperatures below +50 °F (+10 °C): Preheating the carburetor Repositioning a shutter allows heated air to be drawn in from around the cylinder and mixed with cold air - this helps prevent carburetor icing. 2 1 An arrow (1) on the shroud indicates the setting of the shutter (2) for summer or winter operation. Meaning of symbols: - "Sun" = summer operation - "Snow crystal" = winter operation 9926BA016 KN 36 FS 460 C-M, FS 460 C-M L, FS 490 C-M, FS 490 C-M L