Instruction Manual

24.3 Standard Setting
H
L
533BA020 KN
► Turn high speed screw (H) counterclockwise
as far as stop (no more than 3/4 turn).
► Turn the low speed screw (L) clockwise as far
as stop, then turn it back 1/4 turn.
24.4 Adjusting Idle Speed
► Carry out the standard setting.
► Start and warm up the engine.
LA
L
533BA021 KN
24.4.1 Engine stops while idling
► Turn the idle speed screw (LA) clockwise until
the chain begins to run – then back it off
2 turns.
24.4.2 Saw chain runs while engine is idling
► Turn the idle speed screw (LA) counterclock‐
wise until the chain stops moving – then turn it
another 2 turns in the same direction.
WARNING
If the chain continues moving when the engine is
idling, have your saw checked and repaired by
your servicing dealer.
24.4.3 Erratic idling behavior, poor accelera‐
tion (even though standard setting of
low speed screw is correct)
Idle setting is too lean
► Turn the low speed screw (L) carefully coun‐
terclockwise, no further than stop, until the
engine runs smoothly and accelerates well.
It is usually necessary to change the setting of
the idle speed screw (LA) after every correction
to the low speed screw (L).
24.5 Fine Tuning for Operation at
High Altitude
A slight correction of the setting may be neces‐
sary if the engine does not run satisfactorily:
► Carry out the standard setting.
► Warm up the engine.
► Turn high speed screw (H) slightly clockwise
(leaner) – no further than stop.
NOTICE
After returning from high altitude, reset the car‐
buretor to the standard setting.
If the setting is too lean there is a risk of engine
damage due to insufficient lubrication and over‐
heating.
25 Spark Arresting Screen in
Muffler
25.1 Spark arresting screen in muf‐
fler
WARNING
To reduce the risk of fire caused by hot particles
escaping from the machine, never operate the
machine without a spark arresting screen, or with
the spark arresting screen damaged. Do not
modify the muffler or spark arresting screen. To
reduce the risk of fire from accumulated debris
such as pine needles, branches or leaves,
ensure that the muffler plugs are in place before
taking up work.
NOTICE
According to the law or regulations in some
countries or federal states, certain operations
may only be carried out if a properly serviced
spark arresting screen is provided.
► If the engine is down on power, check the
spark arresting screen in the muffler.
► If the muffler plugs are missing or damaged,
mount new plugs.
STIHL recommends that maintenance and repair
work be carried out only by authorized STIHL
dealers.
25 Spark Arresting Screen in Muffler English
0458-533-8321-E 33