Adjusting The Carburetor - Stihl MS 880 Manual De Instrucciones

English

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 adjusting screws 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.
N Turn the high speed screw (H)
counterclockwise as far as possible
(max. 1/2 turn)
N Turn the low speed screw (L)
clockwise – as far as possible – then
back off 1/4 turn.
38
Setting the idle speed
Engine stops when idling
N Set the low speed screw (L) so that
it is 1/4 turn open.
N Turn the idle speed adjusting
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 the low speed screw (L) so that
it is 1/4 turn open.
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 it checked by a
servicing dealer.
Speed erratic when idling; poor
acceleration (despite low speed
screw = 1/4)
Idle setting is too lean –
N Turn the low speed screw (L)
counterclockwise until the engine
runs and accelerates smoothly – but
no further than the stop
Whenever the low speed screw (L) has
been adjusted, at least one adjustment
must also be made on the idle speed
adjusting screw (LA).
Correcting the carburetor setting for
use at high altitudes
The setting may have to be marginally
corrected if engine performance is
unsatisfactory at high altitudes.
N Check the standard setting
N Let the engine warm up
N Turn the high speed screw (H)
clockwise (leaner) – max. up to the
stop
If you make the setting too lean it
will increase the risk of engine
damage through lack of
lubrication and overheating.
MS 880