Fine Tuning; Adjusting Idle Speed - Stihl FC 55 Manual De Instrucciones

English / USA
Standard Setting
: Shut off the engine.
: Mount cutting blade and clean it if
necessary (make sure it is not
damaged or warped).
: Check the air filter and replace if
necessary.
: 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.

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.
24
: Carry out standard setting.
: Warm up engine for about 5
minutes.
: Open the throttle wide.
At high altitude
: Rotate the high speed screw (H)
clockwise (leaner):
Turn about 1/4 turn for every 1,000
meters (3,300 feet) difference in
altitude, but no further than stop.
At sea level
: Rotate the high speed screw (H)
counterclockwise (richer):
Turn about 1/4 turn for every 1,000
meters (3,300 feet) difference in
altitude, but no further than stop.
It is possible that maximum engine
speed will already be reached with
the standard setting.

Adjusting Idle Speed

It is usually necessary to change the
setting of the idle speed screw (LA)
after every correction to the low speed
screw (L).
: Warm up engine for about 5
minutes.
Engine stops while idling
: Turn idle speed screw (LA) slowly
clockwise until the engine runs
smoothly – cutting blade must not
rotate.
Cutting blade rotates when engine is
idling
: Turn idle speed screw (LA) slowly
counterclockwise until cutting blade
stops rotating and then turn the
screw about another 1/2 to 1 turn in
the same direction.
Erratic idling behavior, engine stops
even though setting of LA screw is
correct, poor acceleration
Idle setting too lean:
: Turn low speed screw (L)
counterclockwise (about 1/4 turn)
until the engine runs and
accelerates smoothly.
Erratic idling behavior
Idle setting too rich:
: Turn low speed screw (L) clockwise
(about 1/4 turn) until the engine runs
and accelerates smoothly.
FC 55