Adjusting Screws - Stihl MS 171 Manual

1
: Check operation:
Lever (1) must engage the air
valve's lever (2) when the throttle
shaft is turned.
The edge of the end cover must line
up with the edge of the carburetor
body.
The sides of the levers (1+2) must
not touch each other.
Clearance "a" = about 0.3 mm,
b 14.4.1
– Reassemble all other parts in the
reverse sequence.

14.4.9 Adjusting Screws

1
3
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.
MS 171, MS 181, MS 211
All manuals and user guides at all-guides.com
The high speed screw H has a
limiter cap, which has to be
removed before the screw is
2
removed.
Always install a new limiter cap.
– Remove the carburetor, b 14.3
– See also carburetor
troubleshooting,
Low speed screw
: Take out the low speed screw (1).
2
: Inspect the tip (arrow) for
damage or wear and replace the
screw if necessary.
– Screw down the low speed screw
L as far as stop.
– Continue with high speed screw
High speed screw
: Use tool 5910 890 4501 to pry the
limiter cap (1) off the high speed
1
screw.
Do not refit a limiter cap. Always
install a new one.
: Take out the high speed
screw (1).
1
1
85