Instruction Manual

MS 170, MS 170 C, MS 180, MS 180 C
English
34
Basic information
The carburetor has been factory-
adjusted to provide the engine with a
optimal fuel-air mixture in all operating
states.
Standard setting
N Check the air filter - replace if
necessary
N Carefully screw the idle speed
screw (LD) down counterclockwise
(left-hand thread) until it is firmly
seated, then 2 turns clockwise
(standard setting LD = 2)
Setting the idle speed
N Start and warm up the engine
N Using the idle speed screw (LD), set
the idle speed correctly: The saw
chain must not rotate
Engine speed too low when idling:
N Turn the idle speed adjusting
screw (LD) slowly clockwise until
the saw chain begins to rotate –
then back off 1/2 turn
Saw chain rotates at idle speed:
N Turn the idle speed adjusting
screw (LD) slowly counterclockwise
until the saw chain stops rotating –
then turn an additional 1/2 turn in
the same direction
WARNING
If the saw chain continues to keep
rotating in idle even after adjustment,
have the chain saw checked by a
servicing dealer.
N If the engine is down on power,
difficult to start or runs poorly at idle
speed, first check the spark plug.
N 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
"Specifications".
Removing the spark plug
N Simultaneously press the throttle
trigger lockout and throttle trigger
and set the Master Control lever to
cold start l
N Remove the shroud – see "Shroud"
MS 170, MS 180
MS 170 2-MIX, 180 2-MIX
Adjusting the Carburetor
207BA029 KN
Spark Plug
207BA036 KN