Spark Plug - Stihl FS 38 Instruction Manual

English
Cutting attachment rotates when engine
is idling
Turn the idle speed screw (LA)
N
counterclockwise 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.
Erratic idling behavior, poor acceleration
(despite correction to setting of LA
screw).
Idle setting is too lean
FS 38 2-MIX
Turn the low speed screw (L)
N
carefully counterclockwise, no
further than stop, until the engine
runs smoothly and accelerates well.
FS 38
Rotate the low speed screw (L)
N
slowly about 1/4 turn
counterclockwise until the engine
runs smoothly and still accelerates
satisfactorily.
Erratic idling behavior
Idle setting is too rich
FS 38 2-MIX
Turn the low speed screw (L) slowly
N
clockwise, no further than stop, until
the engine runs smoothly and still
accelerates satisfactorily.
20
FS 38
Rotate the low speed screw (L)
N
slowly about 1/4 turn clockwise until
the engine runs smoothly and still
accelerates satisfactorily.
It is usually necessary to change the
setting of the idle speed screw (LA) after
every correction to the low speed
screw (L).
Fine Tuning for Operation at High
Altitude
A slight correction of the setting may be
necessary if the engine does not run
satisfactorily:
FS 38 2-MIX
Carry out the standard setting.
N
Warm up the engine.
N
Turn high speed screw (H) slightly
N
clockwise (leaner) – no further than
stop.
FS 38 2-MIX
Carry out the standard setting.
N
Warm up the engine.
N
Turn high speed screw (H) slightly
N
clockwise (leaner) – no more than a
3/4 turn.
NOTICE
After returning from high altitude, reset
the carburetor to the standard setting.
If the setting is too lean there is a risk of
engine damage due to insufficient
lubrication and overheating.

Spark Plug

If the engine is down on power,
N
difficult to start or runs poorly at idle
speed, first check the spark plug.
Fit a new spark plug after about 100
N
operating hours – or sooner if the
electrodes are badly eroded. Install
only suppressed spark plugs of the
type approved by STIHL – see
"Specifications".
Removing the Spark Plug
Move the stop switch to 0.
N
1
Pull off the spark plug boot (1).
N
Unscrew the spark plug.
N
FS 38