Instruction Manual

► Turn the low speed screw (L) counterclock‐
wise 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).
21.7 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 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.
22 Spark Plug
► If the engine is down on power, difficult to start
or runs poorly at idle speed, first check the
spark plug.
► Fit a new spark plug after about 100 operating
hours – or sooner if the electrodes are badly
eroded. Install only suppressed spark plugs of
the type approved by STIHL – see "Specifica‐
tions".
22.1 Remove the spark plug
► Move the Master Control lever to the stop
position 0
► Push the hand guard forwards – the saw chain
is blocked
1
4903BA002 KN
1
1
2
► Loosen screws (1)
► Remove the shroud (2)
4903BA007 KN
► Pull off the spark plug boot
► Unscrew spark plug
22.2 Checking the Spark Plug
000BA039 KN
A
► Clean dirty spark plug.
► Check electrode gap (A) and readjust if neces‐
sary – see "Specifications".
► Rectify the problems which have caused foul‐
ing of the spark plug.
Possible causes are:
–
Too much oil in fuel mix.
–
Dirty air filter.
–
Unfavorable running conditions.
1
000BA045 KN
22 Spark Plug English
0458-542-0121-E 29