Stihl MS 391 Safety Manual

MS 311, MS 391
English
28
N Push the clip (1) up and to the rear
and tilt the air filter toward the rear
handle and remove it
N Always replace a damaged filter
For versions with "fleece filter with felt
prefilter"
N Separate felt filter (1) from fleece
filter (2) – clean, see "Cleaning the
air filter"
Cleaning the air filter
N Knock out the filter or blow it clear
with compressed air from the inside
outwards
In case of stubborn dirt:
N Wash the filter in STIHL special-
purpose cleaner (special
accessories) or a clean, non-
flammable cleaning liquid (e.g.,
warm soapy water) and dry it
The felt prefilter protects the fleece filter
and increases its service life. Thus it
should be replaced at shorter intervals
than the fleece filter.
Installing the air filter
N Insert the lugs (1) into the
recesses (2)
N Tilt the air filter toward the filter
housing and close the clip
N Refit the shroud and tighten the
screws
General Information
The carburetor comes from the factory
with a standard setting.
This setting provides an optimum fuel-air
mixture under most operating
conditions.
With this carburetor it is only possible to
correct the adjusting screws within fine
limits.
Standard setting
N Shut off the engine
N Check the air filter and clean or
replace if necessary.
N Check the spark arresting screen
(country-specific) in the muffler and
clean or replace if necessary.
4903BA006 KN
1
0001BA012 KN
1
2
Do not clean fleece filters with a
brush!
0001BA007 KN
1
2
Adjusting the Carburetor
If the setting is too lean there is a
risk of engine damage due to
insufficient lubrication and
overheating.
LA
0001BA008 KN

Stihl MS 391 Specifications

General

Motor type	2-stroke motor
Chain gauge	1.6 mm
Chain pitch	3/8 \
Automatic oiling	Yes
Oil tank capacity	0.35 L
Fuel tank capacity	0.6 L
Engine displacement	64.1 cm³
Engine power	4.4 hp
Power source	Gasoline

Weight and Dimensions

Weight	6200 g