Carburetors with H, L and LA screws
Cutting tool rotates when engine is idling: Turn the idle speed screw (LA) counterclockwise until the cutting tool stops rotating then turn the screw about another half to one full turn in the same direction from that position.
Carburetors with LD screw
Carefully screw the idle speed screw (LD) down onto its seat counterclockwise (left-hand thread).
Then open it two full turns clockwise.
Adjusting Idle Speed: Carry out standard setting.: Start and warm up the engine.
Engine stops while idling: Turn the idle speed screw (LD) clockwise until the engine runs smoothly the cutting tool must not rotate.
Cutting tool rotates when engine is idling: Turn the idle speed screw (LD) counterclockwise until the cutting tool stops rotating then turn the
screw about another one full turn in the same direction from that position.
Erratic idling behavior, poor acceleration
: Turn the idle speed screw (LD) slowly counterclockwise no more than one half turn. 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.
Standard Setting
: Shut off the engine.
: Mount approved cutting tool.
: Check the air filter and replace if necessary.
: Check adjustment of the throttle cable and readjust if necessary see "Adjusting the Throttle Cable".
: Turn high speed screw (H) counterclockwise (max. 3/4 turn) as far as stop.
: Carefully screw the low speed screw (L) down onto its seat. Then
open it one turn counterclockwise. : Start the engine and run it until it is warm.
: Adjust idle speed with the idle speed screw (LA) so that the cutting tool does not rotate.
