Stihl MS 231 Instruction Manual page 31

24 Adjusting the Carburetor
24.2 Standard setting
► Switch off the engine
► Check the air filter – clean or replace it if nec‐
essary
► Turn the high speed adjusting screw (H) coun‐
terclockwise as far as possible (max. 3/4 turn)
► Turn the low speed adjusting screw (L) clock‐
wise until it is firmly in its seat – then back off
1/4 turn
24.3 Setting the idle speed
► Make standard setting
► Start engine and let it warm up
24.3.1 Engine stops when idling
► Turn the idle speed adjusting screw (LA)
clockwise until the saw chain begins to run –
then turn it back 2 3/4 turn.
24.3.2 Saw chain rotates at idle speed
► Turn the idle speed screw (LA) counterclock‐
wise until the saw chain stops turning – then
turn another 2 3/4 turns in the same direction
0458-737-8321-C
WARNING
If the saw chain continues to keep rotating in idle
even after adjustment, have the chain saw
checked by a servicing dealer.
24.3.3 Speed erratic when idling; poor accel‐
eration (despite standard setting of low
speed adjusting screw)
The idle setting is too lean.
► Carefully turn the low speed adjusting
screw (L) counterclockwise until the engine
runs smoothly and accelerates properly.
Whenever the low speed adjusting screw (L) has
been adjusted, it is usually also necessary to
readjust the idle speed adjusting screw (LA).
24.4 Correcting the carburetor set‐
ting for use at high altitudes
The setting may have to be marginally corrected
if engine performance is unsatisfactory at high
altitudes:
► Make standard setting
► Let the engine warm up
► Turn the high speed adjusting screw (H)
slightly clockwise (leaner) – max. up to the
stop
English
31