Stihl MS 391 User Manual

74 MS 311, MS 391
: If there is an annular indentation
(arrow) on the sealing cone of the
inlet needle, fit a new inlet
needle.
Installing
: Fit the inlet needle (1).
: Fit the spring (2) in the bore.
165RA348 TG
1
2
0001RA363 TG
: Position the inlet control lever (3)
with spindle (2) on the spring
(arrow) first, then slide the inlet
control lever’s clevis into the
groove in the inlet needle (1).
Make sure the spring locates on the
control lever’s nipple.
– Press the inlet control lever down
and secure it with the screw.
– Check that the inlet control lever
moves freely.
– Install the metering diaphragm,
b 12.6.1
0001RA364 TG
1 2 3
12.6.3 Pump Diaphragm
– Troubleshooting, b 3.6
– Remove the carburetor, b 12.5
: Take out the screw (1).
– Remove the end cover (2).
If the gasket and pump diaphragm
are stuck to the carburetor, remove
them very carefully.
: Carefully remove the pump
diaphragm with gasket.
0001RA366 TG
1
2
0001RA367 TG

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