Stihl FS 45 Instruction Manual page 26

Rule of thumb
Turn high speed screw (H) about
1/4 turn over for every 1000m
(3.300 ft) change in altitude.
Conditions for adjustment
Carry out adjustment with nylon line
mowing head, making sure the
cutting lines are at full length (as far
as limiter blade on deflector).
: Carry out standard setting without
changing the high speed screw (H).
: Warm up engine for about
3 minutes.
: Open the throttle wide.
FS 45
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.
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.
English
to 1 turn in
2
1
/ turn)
4
25