Adjusting The Carburetor - Stihl FS 38 Instruction Manual

Adjusting the Carburetor

General Information
The carburetor comes from the factory
with a standard setting.
This setting provides an optimum fuel-air
mixture under most operating
conditions.
Preparations
Shut off the engine.
N
Mount the cutting attachment.
N
Check the air filter and clean or
N
replace if necessary.
Different Standard Settings
Different carburetors are installed at the
factory. A different standard setting is
necessary for each of these carburetors.
FS 38
FS 38 2-MIX
L
Turn high speed screw (H)
N
counterclockwise as far as stop (no
more than 3/4 turn).
Turn the low speed screw (L)
N
carefully clockwise until it is against
its seat, then it back it off a 3/4 turn.
FS 38
L
Turn the high speed screw (H)
N
carefully clockwise until it is against
its seat, then turn it back 2 full turns.
Turn the low speed screw (L)
N
carefully clockwise until it is against
its seat, then turn it back 1 1/2 turns.
Adjusting Idle Speed
Carry out the standard setting.
N
Start and warm up the engine.
N
Engine stops while idling
Turn the idle speed screw (LA)
N
slowly clockwise until the engine
runs smoothly – the cutting
attachment must not rotate.
English
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