English / USA
Adjusting the Carburetor
Standard Setting
Rule of thumb:
Turn high speed screw (H) about 1/4
turn for every 3300 ft (1000m)
change in altitude.
:
:
:
Shut off the engine.
Mount approved cutting tool.
Check the air filter and clean or
replace it if necessary.
At high altitude
H L
:
Turn high speed screw (H) clock-
wise (leaner) no further than stop
until there is no noticeable increase
in engine speed.
:
:
Check spark arresting screen* and
clean or replace if necessary.
Turn high speed screw (H)
counterclockwise as far as stop, i.e.
1/4
turn from max. lean setting.
At sea level
Turn high speed screw (H) counter-
clockwise (richer) no further than
stop until there is no noticeable
increase in engine speed.
LA
:
Turn low speed screw (L) clockwise
as far as stop – then back off the
screw one quarter of a turn.
:
:
:
Start and warm up the engine.
It is possible that maximum engine
speed may be reached with the
standard setting in each case.
Adjust idle speed with the idle speed
screw (LA) so that the cutting tool
does not rotate.
Adjusting Idle Speed
The carburetor comes from the factory
with a standard setting.
Fine Tuning
It is usually necessary to change the
setting of the idle speed screw (LA)
after every correction to the low speed
screw (L).
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, at sea level or
after changing the cutting tool.
This settingprovides an optimum fuel-air
mixture under most operating
conditions.
:
Warm up the engine.
Engine stops while idling
:
Turn idle speed screw (LA) slowly
clockwise until the engine runs
smoothly – the cutting tool must not
rotate.
*
see “Guide to Using this Manual”
30
FS 500, FS 550
| Categories | Blower Vacuum and Sweeper Manuals, STIHL Trimmer Manuals, Trimmer Manuals |
|---|---|
| Tags | STIHL FS 500, STIHL FS 550 |
| Download File |
|
| Language | English, Español |
| Product Brand | STIHL. Stihl Inc, USA - Corporate phone: (757) 486-9100. International Support Information: http://stihl.com Email: info@stihl.com, Trimmer |
| Document File Type | |
| Publisher | stihl.com |
| Wikipedia's Page | Stihl |
| Copyright | Attribution Non-commercial |
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