FS 38
English
24
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.
Preparations
N Shut off the engine.
N Mounting the Cutting Attachment
N Check the air filter and clean or 
replace if necessary.
N Check the spark arresting screen 
(not in all models, country-specific) 
in the muffler and clean or replace if 
necessary.
Standard Setting
N Turn high speed screw (H) 
counterclockwise as far as stop (no 
more than 3/4 turn).
N Turn the low speed screw (L) 
carefully clockwise until it is against 
its seat, then it back it off a 3/4 turn.
Adjusting Idle Speed
N Carry out the standard setting.
N Start and warm up the engine.
Engine stops while idling
N Turn the idle speed screw (LA) 
slowly clockwise until the engine 
runs smoothly – the cutting 
attachment must not rotate.
Engine Management Adjusting the Carburetor