Stihl MS 391 Safety Manual

MS 311, MS 391
English
39
Cooling inlets Clean X
Air inlet on fan housing Clean X XX
Cylinder fins Clean XX X
Preseparator port and carburetor body Clean X
"Carb preheat" shutter and preheating port Clean (winter operation only) X
Carburetor
Check idle adjustment – chain must not
rotate
XX
Readjust idle X
Spark plug
Readjust electrode gap X
Replace after every 100 operating hours
All accessible screws and nuts (not adjust-
ing screws)
3)
Retighten X
Spark arresting screen
4)
in muffler
Check X
Clean or replace X
Chain catcher
Check X
Replace X
Safety labels Replace X
1)
STIHL recommends a STIHL servicing dealer.
2)
see chapter on "Chain Brake"
3)
Firmly tighten down the cylinder base screws of chain saws (3.4 kW or more) after 10 to 20 hours of operation.
4)
not in all versions, market-specific
The following intervals apply to normal operating conditions only. If your daily work-
ing time is longer or operating conditions are difficult (very dusty work area, resin-
rich wood, tropical wood, etc.), shorten the specified intervals accordingly. If you only
use the saw occasionally, extend the intervals accordingly.
before starting work after finishing work or daily after each refueling stop weekly monthly every 12 months if problem if damaged if required

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