90
MS 271 C, MS 291 C
:
Screw down the high speed
screw
H
(1) as far as stop.
– Continue with "Pre-installing
limiter cap".
Pre-installing limiter cap
Make sure the stop on the limiter
cap is clear of the stop on the
carburetor body.
:
Line up the new limiter cap (1) so
that the notch (arrow) points
vertically upwards.
:
Push the new limiter cap (1) onto
the high speed screw (
H
) as far
as the first detent (arrow)
– do not push fully home.
1
5902RA410 TG
1
5902RA411 TG
When pushing the limiter cap into
position, check that the stop (1) on
the limiter cap butts against the
right-hand side of the carburetor's
stop (2).
The basic setting with the pre-
installed limiter cap is carried out
with screwdriver 5910 890 2306.
– Reassemble in the reverse
sequence.
– Carry out the basic setting,
b
12.7.1
12.7
Adjusting the Carburetor
12.7.1 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.
It is necessary to carry out the basic
setting after removing the limiter
cap.
The carburetor, air filter and
grommet are installed, the adjusting
screws fitted and the new limiter cap
pre-installed.
– Check chain tension and adjust if
necessary.
5902RA610 TG
2
1
– Inspect the spark arresting
screen (if fitted) and clean or
replace if necessary,
3.7 or
b
6.1
– Check the air filter and clean or
replace if necessary,
b
12.1
For the sake of clarity the adjusting
screws are shown on the exposed
carburetor.
:
Starting with the high speed
screw
H
(1) against its seat,
open it
1 1/2 turns
counterclockwise
– this is the basic setting.
:
Starting the with low speed screw
L
(2)
against its seat, open it
1 full turn
counterclockwise
– this is the basic setting.
– Warm up the engine.
The setting disc 5910 893 6600
may be fitted on the screwdriver
5910 890 2306 to aid adjustment.
5902RA412 TG
1
2
