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 Plug
- 22.1 Remove the spark plug
- 22.2 Checking the Spark Plug
- 22.3 Install spark plug
23 Storing the Machine
24 Checking and Replacing the Chain Sprocket
- 24.1 Fit new chain sprocket
- 24.2 Install spur chain sprocket / rim sprocket
25 Maintaining and Sharpening the Saw Chain
- 25.1 Sawing effortlessly with a properly sharpened saw chain
- 25.2 Chain pitch
- 25.3 Sharpening and side plate angles
- 25.4 File holder
- 25.5 To check the angles
- 25.6 Proper sharpening
- 25.7 Depth gauge setting
- 25.8 Lowering the depth gauges
26 Maintenance and Care
27 Minimize Wear and Avoid Damage
- 27.1 Maintenance Work
- 27.2 Parts Subject to Wear and Tear
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

► Remove clutch drum or spur chain

sprocket (5) including needle cage (6) from the

crankshaft – with QuickStop Super chain

brake, press throttle trigger lockout before‐

hand

24.2 Install spur chain sprocket / rim

sprocket

► Clean crankshaft stub and needle cage and

lubricate with STIHL lubricant (special acces‐

sory)

► Slide needle cage onto the crankshaft stub

► After refitting, turn the clutch drum and/or spur

chain sprocket approx. 1 full turn so that the

carrier for the oil pump drive engages – with

QuickStop Super chain brake, press throttle

trigger lockout beforehand

► Refit the rim sprocket – cavities toward the

outside

► Refit washer and E-clip on the crankshaft

25 Maintaining and Sharpen‐

ing the Saw Chain

25.1 Sawing effortlessly with a prop‐

erly sharpened saw chain

A properly sharpened saw chain cuts through

wood effortlessly even with very little pushing.

Never use a dull or damaged saw chain – this

leads to increased physical strain, increased

vibration load, unsatisfactory cutting results and

increased wear.

► Clean the saw chain

► Check the saw chain for cracks and damaged

rivets

► Replace damaged or worn chain components

and adapt these parts to the remaining parts in

terms of shape and level of wear – rework

accordingly

Carbide-tipped (Duro) saw chains are especially

wear-resistant. For an optimal sharpening result,

STIHL recommends STIHL servicing dealers.

WARNING

Compliance with the angles and dimensions lis‐

ted below is absolutely necessary. An improperly

sharpened saw chain – especially depth gauges

that are too low – can lead to increased kickback

tendency of the chain saw – risk of injury!

25.2 Chain pitch

689BA027 KN

The chain pitch marking (a) is embossed in the

area of the depth gauge of each cutter.

Marking (a) Chain pitch

Inches mm

7 1/4 P 6.35

1 or 1/4 1/4 6.35

6, P or PM 3/8 P 9.32

2 or 325 0.325 8.25

3 or 3/8 3/8 9.32

4 or 404 0.404 10.26

The diameter of file to be used depends on the

chain pitch – see table "Sharpening tools".

The angles of the cutter must be maintained dur‐

ing resharpening.

25.3 Sharpening and side plate

angles

689BA021 KN

A Sharpening angle

STIHL saw chains are sharpened with a 30°

sharpening angle. Ripping chains, which are

sharpened with a 10° sharpening angle, are

25 Maintaining and Sharpening the Saw Chain English

0458-542-0121-E 31