Motor Management; Adjusting The Carburetor - Stihl FS 80 Instruction Manual

Motor 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 80, FS 80 R, FS 85, FS 85 R

Adjusting the Carburetor

H
3 / 4
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
adjust the engine idle speed within fine
limits.!
Standard Setting
: Shut off the engine.
: Mount FS cutting tool, Power Tool
Attachment or CombiTool.
L
1
: Check the air filter and replace if
necessary.
: Check adjustment of throttle cable –
adjust if necessary – see "Adjusting
the Throttle Cable".
: Turn high speed screw (H)
counterclockwise (max.
far as stop.
LA
: Carefully screw the low speed
screw (L) down onto its seat. Then
open it one turn counterclockwise.
: Start and warm up the engine.
: Adjust idle speed with the idle speed
screw (LA) so that the cutting tool
does not rotate.
Fine Tuning
A slight correction of the setting of the
high speed screw (H) may be necessary
if engine power is not satisfactory when
operating at high altitude or at sea level
or after changing the cutting tool.
English / USA
3
/ turn) as
4
39