Engine Management; Adjusting The Carburetor - Stihl FS 40 Manual De Instrucciones

Engine Management

Exhaust emissions are controlled by the
design of the fundamental engine
parameters and components (e.g.
carburation, ignition, timing and valve or
port timing) without the addition of any
major hardware.
FS 40, FS 40 C, FS 50, FS 50 C

Adjusting the Carburetor

The carburetor comes from the factory
with a standard setting.
This setting provides an optimum fuel-air
mixture under most operating
conditions.
With this carburetor it is only possible to
make corrections with the adjusting
screws within fine limits.
Standard Setting
Shut odd the engine.
N
Mount a cutting tool – we
N
recommend you use a mowing
head.
Check the air filter and replace the
N
element if necessary.
Have the spark arresting screen
N
(not all markets) checked – see
"Inspection and Maintenance by
Dealer"
Turn the high speed screw (H)
N
counterclockwise as far as stop
(max. 3/4 turn possible).
Turn the low speed screw (L)
N
counterclockwise as far as stop
(max. 3/4 turn possible).
Start and warm up the engine if
N
necessary.
Adjust idle speed with the idle speed
N
screw (LA) so that the cutting tools
does not turn.
Fine Tuning for Operation in Mountains
or at Sea Level
A slight correction of the setting may be
necessary if engine power is not
satisfactory when operating at high
altitude or at sea level.
Warm up the engine.
N
At high altitude
Turn high speed screw (H)
N
clockwise (leaner) – no further than
stop.
At sea level
Turn high speed screw (H)
N
counterclockwise (richer) – no
further than stop.
Adjusting Idle Speed
Warm up the engine.
N
Engine stops while idling
Turn the idle speed screw (LA)
N
slowly clockwise until the engine
runs smoothly – the cutting
attachment must not turn.
English
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