Adjusting The Carburetor; General Information; Adjusting Idle Speed - Stihl FS 300 Manual De Instrucciones

16 Adjusting the Carburetor

► Turn the choke knob to g.
► Press in the tab (1) and remove the filter
cover (2).
► Clean away loose dirt from around the filter (3)
and inside the filter cover.
► Remove and check the filter element – replace
it if is dirty or damaged.
► Install the filter element in the filter cover.
► Refit the filter cover.
16 Adjusting the Carburetor
16.1

General Information

The carburetor comes from the factory with a
standard setting.
This setting provides an optimum fuel-air mixture
under most operating conditions.
16.2 Preparations
► Shut off the engine.
► Mount the cutting attachment.
► Check the air filter and clean or replace if nec‐
essary.
► Check that the throttle cable is properly adjus‐
ted – readjust if necessary – see chapter on
"Adjusting the Throttle Cable".
16.3 Standard Setting
– High speed screw (H) = 1 1/2
– Low speed screw (L) = 1
H
► Turn the high speed screw (H) carefully clock‐
wise until it is against its seat, then turn it back
2 full turns.
► Turn the low speed screw (L) carefully clock‐
wise as far as stop, then turn it back 1 turn
16.4

Adjusting Idle Speed

► Carry out standard setting.
► Start and warm up the engine.
0458-579-8721-B
L
LA
16.4.1 Engine stops while idling
► Turn the idle speed screw (LA) clockwise until
the engine runs smoothly – the cutting attach‐
ment must not rotate.
16.4.2 Cutting attachment rotates when
engine is idling
► Turn the idle speed screw (LA) counterclock‐
wise until the cutting attachment stops moving
and then turn the screw another 1/2 to 1 full
turn in the same direction.
WARNING
If the cutting attachment continues to rotate
when the engine is idling, have your machine
checked and repaired by your servicing dealer.
16.4.3 Erratic idling behavior, poor accelera‐
tion (even though setting of LA screw
is correct).
Idle setting is too lean
► Turn the low speed screw (L) counterclock‐
wise, no more than 1/2 turn, until the engine
runs and accelerates smoothly.
16.4.4 Erratic idling behavior
Idle setting is too rich
► Turn the low speed screw (L) clockwise, no
more than 1/2 turn, until the engine runs and
accelerates smoothly.
It is usually necessary to change the setting of
the idle speed screw (LA) after every correction
to the low speed screw (L).
16.5 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 standard setting.
► Warm up the engine.
► Turn high speed screw (H) slightly clockwise
(leaner) – no more than a 3/4 turn.
English
71