Adjusting The Carburetor - Stihl MS 200 Instruction Manual

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Adjusting the Carburetor

Basic information
The carburetor comes from the factory
with a standard setting.
The carburetor has been adjusted for
optimum performance and fuel
efficiency in all operating states.
The high speed adjusting screw on this
carburetor can only be set within narrow
limits.
Standard setting
N Switch off engine
N Check the air filter – clean or
replace it if necessary.
N Check the spark arresting screen in
the muffler (present only in some
countries) – clean or replace it if
necessary
28
N Turn the high speed screw (H)
counterclockwise as far as possible
(max. 3/4 turn)
N Turn the low speed screw (L) gently
clockwise until it is firmly in its seat.
N Open the low speed screw (L) 1 full
turn
Setting the idle speed
Engine stops when idling
N Set low speed screw (L) to standard
setting
N Turn the idle speed screw (LA)
clockwise until the saw chain begins
to run – then turn it back 1/4 turn.
Saw chain rotates at idle speed
N
Set low speed screw (L) to standard
setting
N Turn the idle speed screw (LA)
counterclockwise until the chain
stops running – then turn another
1/4 turn in the same direction.
If the saw chain continues to keep
rotating in idle even after
adjustment, have the chain saw
checked by a servicing dealer.
Speed erratic when idling; poor
acceleration
N
Set low speed screw (L) to standard
setting
N Idle speed setting is too lean – turn
the low speed screw (L)
counterclockwise until the engine
runs and accelerates smoothly
Whenever the low speed screw (L) has
been adjusted, it is usually also
necessary to adjust the idle speed
screw (LA).
Adjustment for use in the mountains
or at sea level
A marginal adjustment may be
necessary if the engine does not run
satisfactorily in the mountains or at sea
level:
N Check the standard setting
N Let the engine warm up
In the mountains
N Turn the high speed screw (H)
slightly clockwise (leaner) – max. up
to the stop
MS 200