Stihl MS 391 Instruction Manual

MS 311, MS 391
English
35
Whenever the low speed screw (L) has
been adjusted, it is usually also
necessary to adjust the idle speed
adjusting screw (LA), see "Setting the
carburetor".
N if the chain saw is extremely cold
(frost formation) – after starting,
bring the engine up to operating
temperature at increased idle speed
(disengage chain brake!)
Cover plate
The cover plate (special accessory)
keeps out powdered or drifting snow.
When the cover plate is used, the slide
must be in the winter position.
If engine trouble occurs, first check
whether use of the cover plate is
necessary
Attach cover plate
N Insert cover plate (1) with both tabs
(arrows) and fasten with the
screws (2)
Positions of Master Control Lever
Stop 0 – engine off – the ignition is
switched off
Normal run position (F) – engine runs or
can fire.
Starting throttle (n) – this position is
used to start a warm engine. The Master
Control lever moves to the normal run
position as soon as the throttle trigger is
squeezed.
Choke shutter closed (l) – this position
is used to start a cold engine.
Setting the Master Control Lever
To move the Master Control lever from
the normal run position (F) to choke
closed (l), press down the throttle
trigger lockout and squeeze the throttle
trigger at the same time and hold them in
that position – now set the Master
Control lever.
To select the starting throttle
position (n), move the Master Control
lever to choke closed (l) first, then
push it into the starting throttle
position (n).
The Master Control lever must be in the
choke closed position (l) for the
changeover to the starting throttle
position (n).
The Master Control lever moves from
the starting throttle position (n) to the
run position (F) when you press down
the throttle trigger lockout and blip the
throttle trigger at the same time.
To switch off the engine, move the
Master Control lever to Stop (0).
Choke shutter closed (l)
– if the engine is cold
– if the engine stalls when you open
the throttle after starting.
– if the fuel tank was run until empty
(engine stopped).
Starting throttle position (n)
– if the engine is warm, i.e. if it has
been running for about one minute.
– after engine begins to fire,
– after clearing a flooded combustion
chamber.
2
4903BA004 KN
2
1
Starting / Stopping the
Engine
STOP
0
001BA140 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