Instruction Manual

ManualsBrandsSTIHL ManualsChainsawsSTIHL MS 391

Table Of Contents

STIHL MS 311, 391
1 Guide to Using this Manual
- 1.1 Pictograms
- 1.2 Symbols in text
- 1.3 Engineering improvements
2 Safety Precautions
- 2.1 General
- 2.2 Intended use
- 2.3 Clothing and Equipment
- 2.4 Transporting
- 2.5 Cleaning
- 2.6 Accessories
- 2.7 Refuelling
- 2.8 Before Starting Work
- 2.9 Starting the chain saw
- 2.10 During operation
- 2.11 After finishing work
- 2.12 Storage
- 2.13 Vibrations
- 2.14 Maintenance and repairs
3 Reactive Forces
- 3.1 Dangers of kickback
- 3.2 Kickback occurs if, e. g.,
- 3.3 Quickstop chain brake:
- 3.4 To reduce the risk of kickback
- 3.5 Pull-in (A)
- 3.6 Pushback (B)
- 3.7 Exercise extreme caution
4 Working Techniques
- 4.1 Sawing
- 4.2 Preparing for felling
- 4.3 Felling notch
- 4.4 Sapwood cuts
- 4.5 Basic information on felling cut
- 4.6 Selecting the appropriate felling cut
- 4.7 Felling cut with stabilizing strap (normal tree)
- 4.8 Felling Cut with Holding Strap (Leaner)
5 Cutting Attachment
- 5.1 Chain Scabbard
- 5.2 Fitting Chain Scabbard Extension
6 Mounting the Bar and Chain
- 6.1 Removing the chain sprocket cover
- 6.2 Disengaging the chain brake.
- 6.3 Fitting the chain
7 Tensioning the Chain
8 Checking Chain Tension
9 Fuel
- 9.1 STIHL MotoMix
- 9.2 Mixing Fuel
- 9.3 Storing Fuel
10 Fueling
- 10.1 Preparing the machine
- 10.2 Opening
- 10.3 Filling Up with Fuel
- 10.4 Closing
- 10.5 If the tank cap cannot be locked in the fuel tank opening
11 Chain Lubricant
12 Filling Chain Oil Tank
- 12.1 Preparations
- 12.2 Fill up with chain oil.
13 Checking Chain Lubrication
14 Chain Brake
- 14.1 Saw chain, lock
- 14.2 Disengage the chain brake.
- 14.3 Checking Operation of the Chain Brake
- 14.4 Chain Brake Maintenance
15 Winter Operation
- 15.1 Remove shroud
- 15.2 Pre-heat carburetor
- 15.3 At temperatures below -10 °C
- 15.4 Cover plate
16 Starting / Stopping the Engine
- 16.1 Positions of the Master Control lever
- 16.2 Adjust Master Control lever
- 16.3 Holding the Chain Saw
- 16.4 Actuating
- 16.5 Starting the Chainsaw
- 16.6 When Engine Begins to Fire
- 16.7 As Soon As the Engine Runs
- 16.8 At Very Low Outside Temperatures
- 16.9 Shut off the engine
- 16.10 If Engine Does Not Start
17 Operating Instructions
- 17.1 During the break-in period
- 17.2 During work
- 17.3 After finishing work
18 Oil Quantity Control
19 Taking Care of the Guide Bar
20 Cleaning the Air Filter
- 20.1 If there is a noticeable loss of engine power
21 Adjusting the Carburetor
- 21.1 General Information
- 21.2 Preparations
- 21.3 Different Standard Settings
- 21.4 Standard Setting A
- 21.5 Standard Setting B
- 21.6 Adjusting Idle Speed
- 21.7 Fine Tuning for Operation at High Altitude
22 Spark Arresting Screen in Muffler
23 Spark Plug
- 23.1 Remove the spark plug
- 23.2 Checking the Spark Plug
- 23.3 Install spark plug
24 Storing the Machine
25 Checking and Replacing the Chain Sprocket
- 25.1 Fit new chain sprocket
- 25.2 Install spur chain sprocket / rim sprocket
26 Maintaining and Sharpening the Saw Chain
- 26.1 Sawing effortlessly with a properly sharpened saw chain
- 26.2 Chain pitch
- 26.3 Sharpening and side plate angles
- 26.4 File holder
- 26.5 To check the angles
- 26.6 Proper sharpening
- 26.7 Depth gauge setting
- 26.8 Lowering the depth gauges
27 Maintenance and Care
28 Main Parts
29 Specifications
- 29.1 Engine
- 29.2 Ignition System
- 29.3 Fuel System
- 29.4 Chain Lubrication
- 29.5 Weight
- 29.6 Cutting Attachment
- 29.7 Noise and Vibration Data
- 29.8 REACH
- 29.9 Exhaust Emissions
30 Ordering Spare Parts
31 Maintenance and Repairs
32 Disposal
33 EC Declaration of Conformity

Rapid 1/4“ 4.0 mm

Picco 3/8" P 5.0 mm

Rapid 3/8“; 0.325“ 6.0 mm

Rapid 0.404“ 7.0 mm

If groove depth is less than specified:

► 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.

20 Cleaning the Air Filter

20.1 If there is a noticeable loss of

engine power

20.1.1 Removing the shroud

► Move the Master Control lever to the stop

position (0).

► Push the hand guard forward – the chain is

locked.

4903BA002 KN

► Open the twist locks (1) by turning them 1/4

turn counterclockwise with the combination

wrench.

► Remove the shroud (2).

20.1.2 Removing the air filter

► 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.

2710BA000 KN

► Rotate the air filter a 1/4 turn counterclockwise

and lift it away in the direction of the rear han‐

dle.

► Always replace a damaged filter.

20.1.3 Cleaning the air filter

► Wash the filter in STIHL special cleaner (spe‐

cial accessory) or a clean, non-flammable sol‐

ution (e.g. warm soapy water). Rinse the filter

from the inside outwards under a jet of water –

do not use a pressure washer.

► Dry the filter components – do not expose to

high temperatures.

► Do not impregnate the filter with oil.

► Reinstall the air filter.

20.1.4 Installing the air filter

2710BA001 KN

► Place the air filter in position.

► Push the air filter in the direction of the filter

housing and turn it clockwise at the same time

until it engages – the "STIHL" name must be

horizontal.

► Install the shroud.

21 Adjusting the Carburetor

21.1 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.

21.2 Preparations

► Shut off the engine.

► Check the air filter and clean or replace if nec‐

essary.

► Check the spark arresting screen (not in all

models, country-specific) in the muffler and

clean or replace if necessary.

20 Cleaning the Air Filter English

0458-542-8321-D 27