Stihl 017 Instruction Manual - Page 41

Adjusting Carburetor with two adjusting screws L LA Motor Management Exhaust emissions are controlled by the design of the fundamental engine parameters and components (e.g. carburetion, ignition, timing and valve or port timing) without the addition of any major hardware. The carburetor does not have a high speed adjusting screw (H screw) but is designed to provide an optimum fuel-air mixture under all operating conditions. The maximum engine speed specified for machines with a conventional carburetor does not apply to this version. No provision is made for adjustment of maximum engine speed. On these machines it is only possible to correct the idling speed within narrow limits. 017, 018 L LA • Check the air filter and clean it if necessary. Carefully screw the low speed screw (L) down onto its seat. Now open it one turn counterclockwise (standard setting, L = 1) • Warm up the engine. It is usually necessary to change the setting of the idle speed screw (LA) after every correction to the low speed screw (L). Turn screws only very slightly and carefully - even minor changes have a noticeable effect on the engine's running behavior. 143BA028 KN Engine stops while idling: 'L' screw must be one turn open. Turn the idle speed screw (LA) clockwise until chain begins to run then back off the screw one quarter of a turn. Chain runs when engine is idling 'L' screw must be one turn open. Turn the idle speed screw (LA) counterclockwise until chain stops running then turn screw another quarter turn in the same direction. Erratic idling behaviour, poor acceleration (even though 'L' screw in one turn open) Idle setting is too lean. Turn the low speed screw (L) counterclockwise until engine runs and accelerates smoothly. 39