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
► Insert the screw plug (1) and tighten it down
firmly.
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, clean and inspect the cutting attach‐
ment. Coat metal cutting attachments with cor‐
rosion inhibitor.
► Thoroughly clean the machine.
► Clean the air filter.
► Store the machine in a dry and secure location
– out of the reach of children and other unau‐
thorized persons.
25 Sharpening Metal Cutting
Blades
► Use a sharpening file (special accessory) to
sharpen dull cutting attachments. In case of
more serious wear or nicks: Resharpen with a
grinder or have the work done by a dealer –
STIHL recommends a STIHL servicing dealer.
► Sharpen frequently, take away as little metal
as possible – two or three strokes of the file
are usually enough.
002BA665 KN
1
2
2
1
2
2
1
2
1
1
► Resharpen the teeth (1) uniformly – do not
alter the contour of the parent blade (2) in any
way.
See cutting attachment packaging for additional
sharpening instructions. Keep the packaging for
future reference.
25.1 Balancing
► After resharpening about 5 times, check the
cutting attachment for out-of-balance on a
STIHL balancer (special accessory) or have it
checked by a dealer and re-balanced as nec‐
essary – STIHL recommends a STIHL servic‐
ing dealer.
26 Maintaining the Mowing
Head
26.1 Placing power tool on the
ground
002BA104 KN
► Shut off the engine.
► Lay your power tool on its back so that the cut‐
ting attachment mounting face is pointing up.
26.2 Replacing Nylon Line
Always check the mowing head for signs of wear
before replacing the nylon line.
WARNING
If there are signs of serious wear, replace the
complete mowing head.
The nylon mowing line is referred to as "nylon
line" or "line" in the following.
The mowing head is supplied with illustrated
instructions for replacing the nylon line. Keep the
instructions for the mowing head in a safe place.
► If necessary, remove the mowing head.
24 Storing the Machine English
0458-426-8321-B 33