Owner's Manual

MS 650, MS 660
English
39
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 screw alters the
engine’s power output and the maximum
off-load engine speed.
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
Carburetors with H = 1 and L = 1
N Carefully turn both adjusting screws
clockwise until they are seated
firmly (clockwise)
N Turn the high speed screw (H) 1 full
turn counterclockwise
N Turn the low speed screw (L) 1 full
turn counterclockwise
Carburetor with H = 3/4 and L = 1/4
N Turn the high speed screw (H)
counterclockwise as far as possible
(max. 3/4 turn)
N Carefully turn the low speed
screw (L) clockwise – as far as
possible – then back off 1/4 turn.
Setting the idle speed
Engine stops when idling
N Set low speed screw 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 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.
Speed erratic when idling; poor
acceleration (despite low speed
screw = standard setting)
N Idle setting too lean – turn low
speed screw (L) counterclockwise
until the engine runs smoothly and
accelerates correctly – with
carburetors with L = 1/4 max. up to
the stop
Adjusting the Carburetor
If you make the setting too lean it
will increase the risk of engine
damage through lack of
lubrication and overheating.
L
H
176BA008 KN
L
H
137BA023 KN
L
H
If the saw chain continues to keep
rotating in idle even after
adjustment, have the chain saw
checked by a servicing dealer.
LA
L
137BA024 KN