Stihl MM 55 Notice D'emploi page 18

English
L
Engine stops while idling
Turn the idle speed screw (LA)
N
clockwise until the engine runs
smoothly – the cutting/working
attachment must not rotate.
Attachment runs when engine is idling
Turn the idle speed screw (LA)
N
counterclockwise until the
cutting/working attachment stops
moving and then turn the screw
another 1/2 to 1 full turn in the same
direction.
WARNING
If the cutting/working attachment
continues to run when the engine is
idling, have your machine checked and
repaired by your servicing dealer.
16
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Erratic idling behavior, poor acceleration
(despite correction to setting of LA
screw).
Idle setting is too lean
Turn the low speed screw (L)
N
carefully counterclockwise, no
further than stop, until the engine
runs smoothly and accelerates well.
Erratic idling behavior
Idle setting is too rich
Turn the low speed screw (L) slowly
N
clockwise 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).
Fine Tuning for Operation at High
Altitude
A slight correction of the setting may be
necessary if the engine does not run
satisfactorily:
Carry out the standard setting.
N
Warm up the engine.
N
Turn high speed screw (H) slightly
N
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.
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".
Remove the spark plug
Move the slide control to STOP-0
N
1
Unplug spark plug boot (1)
N
Unscrew spark plug
N
MM 55, MM 55 C