Adjusting The Carburetor - Stihl FC 85 Manual De Instrucciones

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 high speed screw within fine
limits.
FC 85
Standard Setting
: Shut off the engine.
:
Mount the cutting blade and clean it
if necessary (make sure it is not
L
1
damaged or warped).
:
Check adjustment of the throttle
cable* and readjust if necessary –
see "Adjusting the Throttle Cable".
:
Check spark arresting screen* and
clean or replace if necessary
:
Check the air filter and replace if
necessary.
LA
:
Turn high speed screw (H)
counterclockwise (max. 3/4 turn)
as far as stop.
:
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 blade
does not rotate.
* see "Guide to Using this Manual"
English / USA
Fine Tuning for Operation
at High Altitudes
A slight correction of the setting of the
high speed screw (H) may be necessary
if engine power is not satisfactory.
Rule of thumb
: Turn high speed screw (H) about
a quarter turn for every 3300 ft
(1000m) change in altitude.
:
Carry out standard setting.
:
Warm up the engine for about 5
minutes.
:
Open the throttle wide.
: Turn high speed screw (H) clock-
wise (leaner) no further than stop
until there is no noticeable increase
in engine speed.
It is possible that maximum engine
speed may be reached with the
standard setting.
23