Adjusting The Carburetor; Basic Setting - Stihl MS 171 Manual

: Inspect the tip (arrow) for
damage or wear and replace the
screw if necessary.
– Screw home high speed screw H
as far as stop.
– Carry out basic setting, b 14.5.1
14.5

Adjusting the Carburetor

14.5.1 Basic Setting

The basic setting is necessary only
if the high speed screw H or low
speed screw L has to be replaced
or after cleaning and adjusting the
carburetor from scratch.
– Remove the limiter cap from the
high speed screw, b 14.4.9
It is necessary to carry out the basic
setting after removing the limiter
cap.
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: Screw down the high speed
screw H (1) clockwise onto its
seat.
: With the high speed
screw H (1) against its seat,
unscrew it one full turn
counterclockwise
– this is the basic setting.
: Screw down the low speed screw
L (2) clockwise onto its seat.
: With the low speed screw L (2)
against its seat, unscrew it one
full turn counterclockwise
– this is the basic setting.
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Always install a new limiter cap.
First position it so that its lug is
below the stop (arrow) and then
press it onto the high speed screw.
: Press the limiter cap (1) onto the
high speed screw H.
a
: Do not push on the limiter cap (1)
as far as stop against the
carburetor body (2) because it
will be damaged. Maintain a
minimum clearance of "a" = 1 mm
(arrow).
The high speed screw H now has a
limited range. The standard setting
is obtained by turning the high
speed screw H counterclockwise
until it engages in position.
MS 171, MS 181, MS 211
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