Instruction Manual
Table Of Contents
- STIHL FS 91, 91 R
- 1 Guide to Using this Manual
- 2 Safety Precautions and Working Techniques
- 2.1 Clothing and equipment
- 2.2 Transporting the machine
- 2.3 Refueling
- 2.4 Before starting
- 2.5 Starting the engine
- 2.6 Holding and guiding the machine
- 2.7 While working
- 2.8 Using mowing heads
- 2.9 When using metal cutting attachments
- 2.10 Vibrations
- 2.11 Maintenance and Repairs
- 2.12 Symbols on Deflectors
- 2.13 Shoulder Strap/Harness
- 2.14 Mowing Head with Nylon Line
- 2.15 STIHL Polycut Mowing Head with Polymer Blades
- 2.16 Risk of Kickout (Blade Thrust) with Metal Cutting Attachments
- 2.17 Grass Cutting Blade
- 2.18 Brush Knife
- 2.19 Circular Saw Blade
- 3 Approved Combinations of Cutting Attachment, Deflector, Handle and Harness
- 4 Approved Power Tool Attachments
- 5 Mounting the Bike Handle
- 6 Mounting the Loop Handle
- 7 Adjusting the Throttle Cable
- 8 Fitting the Carrying Ring
- 9 Mounting the deflector
- 10 Mounting the Cutting Attachment
- 10.1 Placing power tool on the ground
- 10.2 Mounting Hardware for Cutting Attachments
- 10.3 Blocking the Shaft
- 10.4 Removing the Mounting Hardware
- 10.5 Mounting the Cutting Attachment
- 10.6 Fitting Mowing Head with Screw Mounting
- 10.7 Remove the mowing head.
- 10.8 Mounting Metal Cutting Attachments
- 10.9 Removing the Metal Cutting Attachment
- 11 Fuel
- 12 Fueling
- 13 Fitting the Harness
- 14 Balancing the Machine
- 15 Starting / Stopping the Engine
- 16 Transporting the Unit
- 17 Operating Instructions
- 18 Replacing the Air Filter
- 19 Adjusting the Carburetor
- 20 Spark Arresting Screen in Muffler
- 21 Spark Plug
- 22 Engine Running Behavior
- 23 Lubricating the Gearbox
- 24 Storing the Machine
- 25 Sharpening Metal Cutting Blades
- 26 Maintaining the Mowing Head
- 27 Maintenance and Care
- 28 Minimize Wear and Avoid Damage
- 29 Main Parts
- 30 Specifications
- 31 Maintenance and Repairs
- 32 Disposal
- 33 EC Declaration of Conformity
18.1 If there is a noticeable loss of
engine power
1
1
0000-GXX-0482-A0
2
3
4
►
Turn the choke knob to g.
► Loosen the screws (1).
► Remove the filter cover (2).
► Clean away loose dirt from around the filter.
► Remove the filter element (3).
► Replace dirty or damaged filter element (3).
► Replace any damaged parts.
18.2 Installing the Filter Element
► Install the filter element (3) in the filter housing
and fit the cover.
► Insert the screws (1) and tighten them down
firmly.
19 Adjusting the Carburetor
The carburetor has been set at the factory to pro‐
vide an optimum fuel-air mixture under most
operating conditions.
19.1 Adjusting Idle Speed
0000-GXX-0495-A0
Engine stops while idling
► Warm up the engine for about 3 minutes.
► Turn the idle speed screw (LA) slowly clock‐
wise until the engine runs smoothly – the cut‐
ting attachment must not run.
Cutting attachment runs when engine is idling
► Turn the idle speed screw (LA) slowly counter‐
clockwise until the cutting attachment stops
running and then turn the screw about another
1/2 to 3/4 turn in the same direction.
WARNING
If the cutting attachment continues to run when
the engine is idling, have your machine checked
and repaired by your servicing dealer.
20 Spark Arresting Screen in
Muffler
WARNING
To reduce the risk of fire caused by hot particles
escaping from the machine, never operate the
machine without a spark arresting screen, or with
the spark arresting screen damaged. Do not
modify the muffler or spark arresting screen.
NOTICE
According to the law or regulations in some
countries or federal states, certain operations
may only be carried out if a properly serviced
spark arresting screen is provided.
► If the engine is down on power, check the
spark arresting screen in the muffler.
► Wait for the muffler to cool down
0000-GXX-0486-A0
4
5
► Undo screw (4)
► Lift the spark arresting screen (5) and pull it
out.
► Clean the spark arresting screen (5). If the
screen is damaged or heavily carbonized,
install a new one.
► Refit the spark arresting screen (5)
► Insert and tighten screw (4)
21 Spark Plug
► If the engine is down on power, difficult to start
or runs poorly at idle speed, first check the
spark plug.
19 Adjusting the Carburetor English
0458-426-8321-B 31