Adjusting The Carburetor - Stihl FS 90 Instruction Manual

Hide thumbs Also See for FS 90:
Table of Contents

Advertisement

English / USA

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
adjust the engine idle speed within fine
limits.
40
Standard Setting
:
Shut off the engine.
:
Mount cutting tool or attachment.
:
Check the air filter – clean or
replace if necessary.
:
Check adjustment of the throttle
cable and readjust if necessary –
see "Adjusting the Throttle Cable".
:
Check the spark arresting screen
(not installed in all countries) and
clean or replace if necessary.
:
Carefully screw both adjusting
screws clockwise down onto their
seats.
:
Open high speed screw (H)
3
/
turn.
4
:
Open low speed screw (L)
3
/
turn.
4
:
Start and warm up the engine
:
Adjust idle speed with the idle speed
screw (LA) so that the 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 tool.
Rule of thumb
:
Turn high speed screw (H) about
a quarter turn for every 1000m
(3300 ft) change in altitude.
:
Carry out standard setting.
:
Warm up engine for about 3
minutes.
:
Open the throttle wide
FS 90, FS 90 R

Hide quick links:

Advertisement

Table of Contents
loading

This manual is also suitable for:

Fs 90 r

Table of Contents