Stihl MS 391 Instruction Manual

MS 311, MS 391
English
40
N Turn the guide bar over – every time
you sharpen the chain and every
time you replace the chain – this
helps avoid one-sided wear,
especially at the nose and
underside of the bar.
N Regularly clean the oil inlet hole (1),
the oilway (2) and the bar groove
(3).
N Measure the groove depth – with the
scale on the filing gauge (special
accessory) – in the area used most
for cutting.
If groove depth is less than specified:
N Replace the guide bar.
The drive link tangs will otherwise
scrape along the bottom of the groove –
the cutters and tie straps will not ride on
the bar rails.
If there is a noticeable loss of engine
power
Removing the shroud
N Move the Master Control lever to the
stop position (0).
N Push the hand guard forward – the
chain is locked.
N Open the twist locks (1) by turning
them 1/4 turn counterclockwise with
the combination wrench.
N Remove the shroud (2).
Removing the air filter
N Clean away loose dirt from around
the filter.
NOTICE
To avoid damaging the filter, do not use
tools for removing and installing the air
filter.
Taking Care of the Guide Bar
2
3
1
143BA026 KN
Chain
type
Chain pitch Minimum
groove depth
Picco 1/4" P 0.16" (4.0 mm)
Rapid 1/4" 0.16" (4.0 mm)
Picco 3/8" P 0.20" (5.0 mm)
Rapid 3/8"; 0.325" 0.24" (6.0 mm)
Rapid 0.404" 0.28" (7.0 mm)
Cleaning the Air Filter
1
4903BA002 KN
1
1
2

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