Adjusting Idle Speed - Stihl FS 55 Serie Manual De Instrucciones

Rule of thumb
Rotate the high speed screw (H) about
1
/ turn for every 1000 meter (3300 ft)
4
change in altitude.
Conditions for adjustment
Carry out adjustment with nylon line
cutting head, making sure the
cutting lines are at full length (as far
as limiter blade on deflector).
Use standard setting for metal
cutting tools.
: Carry out standard setting without
altering position of the high speed
screw (H).
: Warm up engine for about
5 minutes if a metal cutting tool is
fitted or about 3 minutes if a nylon
line cutting head is fitted.
: Open the throttle wide.
FS 55
At high altitudes
: Turn the high speed screw (H)
clockwise (leaner) no further than
stop until there is no noticeable
increase in engine speed.
At sea level
: Turn the high speed screw (H)
counterclockwise (richer) no further
than stop until there is no noticeable
increase in engine speed.
It is possible that maximum engine
speed will already be reached with
the standard setting in each case.

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.
Engine stops while idling
: Turn idle speed screw (LA) slowly
clockwise until the engine runs
smoothly – cutting tool must not
rotate.
English / USA
Cutting tool rotates when engine is
idling
: Turn idle speed screw (LA) slowly
counterclockwise until cutting tool
stops rotating and then turn the
1
screw about another /
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
until the engine runs and
accelerates smoothly.
Erratic idling behavior
Idle setting too rich:
: Turn low speed screw (L) clockwise
1
(about / turn) until the engine runs
4
and accelerates smoothly.
to 1 turn in
2
1
/ turn)
4
35