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

4903BA007 KN

► Pull off the spark plug boot

► Unscrew spark plug

23.2 Checking the Spark Plug

000BA039 KN

► Clean dirty spark plug.

► Check electrode gap (A) and readjust if neces‐

sary – see "Specifications".

► Rectify the problems which have caused foul‐

ing of the spark plug.

Possible causes are:

–

Too much oil in fuel mix.

–

Dirty air filter.

–

Unfavorable running conditions.

000BA045 KN

WARNING

Arcing may occur if the adapter nut (1) is loose

or missing. Working in an easily combustible or

explosive atmosphere may cause a fire or an

explosion. This can result result in serious inju‐

ries or damage to property.

► Use resistor type spark plugs with a properly

tightened adapter nut.

23.3 Install spark plug

4903BA008 KN

► Screw in the spark plug and press on the

spark plug boot

► Refit the shroud and tighten the screws

24 Storing the Machine

For periods of 3 months or longer

► Drain and clean the fuel tank in a well ventila‐

ted area.

► Dispose of fuel properly in accordance with

local environmental requirements.

► Run the engine until the carburetor is dry – this

helps prevent the carburetor diaphragms stick‐

ing together.

► Remove the saw chain and guide bar, clean

them and spray with corrosion inhibiting oil.

► Thoroughly clean the machine – pay special

attention to the cylinder fins and air filter.

► If you use a biological chain and bar lubricant,

e.g. STIHL BioPlus, completely fill the chain oil

tank.

► Store the machine in a dry, high or locked

location, out of the reach of children and other

unauthorized persons.

25 Checking and Replacing

the Chain Sprocket

► Remove chain sprocket cover, saw chain and

guide bar.

► Release chain brake – pull hand guard against

the front handle

English 24 Storing the Machine

30 0458-542-8321-D