Stihl SH 56, Instruction Manual, Page: 20 / 32

BG 56, BG 56 C, BG 66, BG 66 C, BG 86, BG 86 C, SH 56, SH 56 C, SH 86, SH 86 C
English
18
Standard setting B
N
Turn high speed screw (H)
counterclockwise as far as stop (no
more than 3/4 turn).
N
Turn the low speed screw (L)
carefully clockwise as far as stop,
then turn it back 3/4 turn.
Adjusting Idle Speed
N
Carry out the standard setting.
N
Start and warm up the engine.
Engine stops while idling
N
Turn the idle speed screw (LA)
clockwise until the engine runs
smoothly.
Erratic idling behavior, poor acceleration
(even though standard setting of low
speed screw is correct)
Idle setting is too lean
N
Turn the low speed screw (L)
counterclockwise, no further than
stop, until the engine runs and
accelerates smoothly.
Erratic idling behavior, engine speed
drops when swinging the machine
Idle setting is too rich
N
Turn the low speed screw (L)
clockwise (1/8 of a turn or 45° at a
time) 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).
Fine Tuning for Operation at High
Altitude
A slight correction of the setting may be
necessary if engine does not run
satisfactorily:
N
Carry out the standard setting.
N
Warm up the engine.
N
Turn high speed screw (H) slightly
clockwise (leaner) – no further than
stop.
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.
296BA010 KN
296BA01
1 KN