Adjusting Screws - Stihl FS 94 Instruction Manual

2
: Carefully pull the control valve (1)
out of the carburetor (2).
– Check the control valve and
replace if necessary.
The needle of the low speed
screw L in the control valve
engages in the carburetor jet.
Remove the low speed screw L to
reduce the risk of damaging the jet
(small plastic tube) when installing
the
control valve.
– Check the low speed screw L,
replace if necessary, b 10.4.5
Installing
2
3
4
: Line up the control valve (1) so
that the rabbet (2) engages over
the shoulder (3), then push it
carefully into the carburetor's (4)
bore (arrow) as far as stop.
– Fit the screws and tighten them
down firmly.
– Install the low speed screw L,
b 10.4.5
Series 4149 Powerhead
Check operation
1
2
: Turn lever (1) counterclockwise
and push it home until it engages
on and is held by lever (2) (arrow)
= cold start position.
When lever (2) is turned in direction
of full throttle, lever (1) is
disengaged and automatically
jumps back to its original position.
When lever (2) is released, it
automatically moves back until it
locates against idle speed
screw LA.
– Install the carburetor, b 10.3
– Reassemble all other parts in the
reverse sequence.

10.4.5 Adjusting Screws

1
2
1
There are three adjusting screws on
the carburetor:
H = high speed screw (1)
L = low speed screw (arrow)
LA = idle speed screw (2)
If the carburetor cannot be adjusted
properly, the problem may be the
adjusting screws.
The high speed screw H and low
speed screw L have a special hex
head and can only be adjusted with
screwdriver 5910 890 2311
– no limiter caps are used.
– See also carburetor
troubleshooting, b 3.4
1
The idle speed screw L is located in
the control valve lever. Exact
adjustments are made difficult
because the lever moves. Use
sleeve 5910 893 1711 to hold the
lever steady while making
adjustments.
Adjusting screws can be removed
and installed with the carburetor in
position.
Low speed screw
1
: Use screwdriver (1)
5910 890 2311 to remove the low
speed L (arrow) from the control
valve.
75