Stihl FS 40, Service Manual

Page: 53 / 82

52 Series 4144 Components FC, FS, KM
– Fit the spring (1) on the choke
shaft.
– Position the rotary knob (2) so
that the flat in the knob's bore
lines up with the flat side (arrow)
of the choke shaft.
:
Push the rotary knob (2) on to the
choke shaft until it engages, and
hold it in that position.
:
Insert screw (arrow) and tighten it
down firmly.
Check operation:
– Press down the rotary knob = it
can be rotated counterclockwise.
– Turn the rotary knob back to the
stop = it springs back to its
original position
– knob is locked.
– Reassemble all other parts in the
reverse sequence.
545RA092 TG
2
1
545RA011 TG
8.4.5 Adjusting Screws
There are three adjusting screws on
the carburetor:
H = high speed screw (1)
L = low speed screw (2)
LA = idle speed screw (3)
If the carburetor cannot be adjusted
properly, the problem may be the
adjusting screws.
The high speed screw H and low
speed screw L each have a limiter
cap, which has to be removed
before the screw is removed.
Always install new limiter caps.
– Remove the filter cover,
b
5.1
It is not necessary to remove the
carburetor to remove and install the
adjusting screws. For the sake of
clarity, however, the illustrations
show the carburetor removed from
the machine.
– See also carburetor
troubleshooting,
b
4.4
545RA012 TG
3
1
2
Low speed screw
:
Use special tool 5910 890 4501
to pry the limiter cap (1) off the
low speed screw.
Do not re-install used cap – always
fit a new cap.
:
Take out the low speed screw (1).
545RA013 TG
1
545RA014 TG
1