Stihl FS 511 C-M User manual

STIHL FS 511 C-M,
561 C-M
Instruction Manual2 - 24

Contents
1 Introduction................................................. 2
2 Guide to Using this Manual.........................2
3 Overview..................................................... 3
4 Safety Precautions......................................4
5 Preparing Trimmer for Operation.............. 11
6 Assembling the Trimmer........................... 11
7 Adjusting Trimmer for User....................... 14
8 Mixing Fuel and Refueling the Brushcutter
.................................................................. 14
9 Starting and Stopping the Engine............. 15
10 Testing the Trimmer..................................16
11 Operating the Trimmer..............................16
12 After Finishing Work..................................19
13 Transporting..............................................19
14 Storing.......................................................19
15 Cleaning....................................................19
16 Maintenance............................................. 19
17 Repairing...................................................20
18 Troubleshooting........................................ 20
19 Specifications............................................21
20 Combinations of Cutting Attachments,
Deflectors and Carrying Systems............. 23
21 Spare Parts and Accessories....................23
22 Disposal.................................................... 23
23 EC Declaration of Conformity................... 23
1 Introduction
Dear Customer,
Thank you for choosing STIHL. We develop and
manufacture our quality products to meet our
customers’ requirements. The products are
designed for reliability even under extreme con‐
ditions.
STIHL also stands for premium service quality.
Our dealers guarantee competent advice and
instruction as well as comprehensive service
support.
STIHL expressly commit themselves to a sus‐
tainable and responsible handling of natural
resources. This user manual is intended to help
you use your STIHL product safely and in an
environmentally friendly manner over a long
service life.
We thank you for your confidence in us and hope
you will enjoy working with your STIHL product.
Dr. Nikolas Stihl
IMPORTANT! READ BEFORE USING AND
KEEP IN A SAFE PLACE FOR REFERENCE.
2 Guide to Using this Manual
2.1 Applicable Documentation
Local safety regulations apply.
► Read, understand and save the following
documents in addition to this instruction man‐
ual:
–Instruction manual and packaging of the
cutting attachment you are using
2.2 Symbols used with warnings in
the text
WARNING
■ This symbol indicates dangers that can cause
serious injuries or death.
► The measures indicated can avoid serious
injuries or death.
NOTICE
■ This symbol indicates dangers that can cause
damage to property.
► The measures indicated can avoid damage
to property.
2.3 Symbols in Text
This symbol refers to a chapter in this
instruction manual.
English
2 0458-856-0121-A
© ANDREAS STIHL AG & Co. KG 2021
0458-856-0121-A. VA0.B21.
Printed on chlorine-free paper Printing inks contain vegetable oils, paper can be recycled.
Translation of Original Instruction Manual 0000009223_004_GB

3 Overview
3.1 Brushcutter
1
24
14
2
54
3
19
13
17
11
18
25
21
22
16
15
20
12
6
8
9
7
10
23
#
0000097391_002
1 Filter cover
Covers the air filter.
2 Air filter
The air filter filters the air entering the engine.
3 Manual fuel pump
The manual fuel pump eases engine starts.
4 Shutter
Serves to select summer or winter operating
mode.
5 Cover
Covers the spark plug.
6 Spark plug boot
Connects the ignition lead to the spark plug.
7 Spark plug
Ignites the fuel-air mixture in the engine.
8 Muffler
Reduces trimmer noise emissions.
9 Starter grip
Serves to crank the engine.
10 Fuel tank cap
Closes the fuel tank.
11 Choke lever
Helps start the engine.
12 Carrying strip
Perforated strip for suspending the carrying
system.
13 Control handle
The control handle is used for operating,
holding and controlling the brushcutter.
14 Throttle trigger
Controls the engine speed.
15 Throttle trigger lockout
Unlocks the throttle trigger.
16 Stop switch
Shuts off the engine.
17 Wing screw
The wing screw secures the handlebar to the
handle support.
18 Handlebar
The handlebar connects control handle and
handle with the shaft.
19 Handle
The handle is for holding and controlling the
brushcutter.
20 Throttle cable
Connects the throttle trigger to the engine.
21 Shaft
The shaft connects all components.
22 Gear housing
The gear housing encloses the gearbox.
23 Opening for stop pin
The opening for the stop pin accommodates
the stop pin.
24 Screw plug
The screw plug closes the filler opening for
STIHL gear grease.
25 Stop pin
The stop pin blocks the shaft while a cutting
attachment is being mounted.
# Rating plate with machine number
3.2 Deflectors and Cutting Attach‐
ments
The illustrations show examples of deflectors
and cutting attachments. Approved combinations
are listed in this instruction manual, 20.
3 Overview English
0458-856-0121-A. VA0.B21. 3

14
5
10
9
6
11
8
7
2
3
0000097392_001
1 Deflector for metal cutting attachments
The metal cutting tool guard protects the user
from thrown objects and contact with the
grass cutting blade or brush knife.
2 Grass Cutting Blade
Cuts grass and weeds.
3 Brush knife
Cuts brushwood.
4 Guard for shredder blades
The shredder blade guard protects the user
from thrown objects and from contact with the
shredding blade.
5 Shredder blades
The shredder blade cuts and shreds thickets.
6 Deflector for mowing heads
Protects user from flying debris and contact
with the mowing head.
7 Line limiting blade
Line limiting blade trims nylon lines to correct
length.
8 Mowing head
Moving head accommodates the mowing
lines.
9 Limit stop
Protects user from flying debris and contact
with the circular saw blade and helps support
the trimmer against the wood during cutting
work.
10 Circular Saw Blade
Cuts shrubs and trees.
11 Transport guard
Helps protect user from contact with metal
cutting attachments.
3.3 Icons
Meanings of symbols that may be on the trimmer
and the deflector:
This icon denotes the fuel tank.
This symbol denotes the manual fuel
pump.
Shutter is in winter mode in this position.
Shutter is in summer mode in this position.
Engine is operated or started with the
choke control in this position.
Engine can be started with the choke con‐
trol in this position.
This symbol marks the stop switch.
This icon shows the direction of rota‐
tion of the cutting attachment.
This icon shows the maximum diame‐
ter of the cutting attachment in millime‐
ters.
This icon shows the rated speed of the cut‐
ting attachment.
L
W
A
Guaranteed sound power level in
accordance with Directive 2000/14/EC
in dB(A) for the purpose of comparing
the sound emissions of products.
4 Safety Precautions
4.1 Warning Signs
4.1.1 Warning Symbols
Meanings of warning signs on the trimmer:
Observe safety notices and take the
necessary precautions.
Read, understand and save the
instruction manual.
Wear safety glasses, hearing protec‐
tion and a hard hat.
Wear safety boots.
English 4 Safety Precautions
4 0458-856-0121-A. VA0.B21.

Wear work gloves.
Observe safety notices on kickback
and take the necessary precautions.
Observe safety notices on flying debris
and take the necessary precautions.
15m (50ft)
Maintain safe distance.
Do not touch hot surface.
4.1.2 Deflector for mowing heads
Meanings of warning signs and labels on the
deflector for mowing heads:
Use this deflector for mowing heads.
Do not use this deflector for grass cut‐
ting blades.
Do nit use this deflector for brush kni‐
ves.
Do not use this deflector for shredder
blades.
Do not use this deflector for circular
saw blades.
4.1.3 Deflector for metal cutting attachments
Meanings of warning signs on the deflector for
metal cutting attachments:
Use this deflector for grass cutting
blades.
Use use this deflector for brush knives.
Do not use this deflector for mowing
heads.
Use this deflector for shredder blades.
Do not use this deflector for circular
saw blades.
4.1.4 Guard for shredder blades
Meanings of warning signs and labels on the
deflector for shredder blades:
Do not sse this deflector for shredder
blades.
Do not use this deflector for mowing
heads.
Do not use this deflector for grass cut‐
ting blades.
Do not use this deflector for brush kni‐
ves.
Do not use this deflector for circular
saw blades.
4.2 Intended Use
The STIHL FS 511 or FS 561 trimmer is
designed for the following applications:
–with a mowing head: Mowing grass
–with a grass cutting blade: Mowing grass and
weeds
–with a brush knife: Cutting brush with a stem
diameter up to 20 mm
–with a shredder blade: mowing and shredding
thickets with a diameter of up to 20 mm
–with a circular saw blade: Cutting shrubs with
a stem diameter up to 70 mm
WARNING
■Using the trimmer for purposes for which it is
not designed may result in serious or fatal inju‐
ries and damage to property.
►Use the brushcutter as described in this User
Manual.
4 Safety Precautions English
0458-856-0121-A. VA0.B21. 5

4.3 The Operator
WARNING
■Users who have had no instruction cannot rec‐
ognize or assess the risks involved in using
the trimmer. The user or other persons may
sustain serious or fatal injuries.
► Read, understand and save the
instruction manual.
► If you pass the trimmer is on to another user:
Always give them the instruction manual.
► Make sure the user meets the following
requirements:
–The user must be rested.
–The user must be in good physical condi‐
tion and mental health to operate and
work with the trimmer. If the user’s physi‐
cal, sensory or mental ability is restricted,
he or she may work only under the
supervision of or as instructed by a
responsible person.
–The user is able to recognize and assess
the risks involved in using the trimmer.
–The user must be of legal age or is being
trained in a trade under supervision in
accordance with national rules and regu‐
lations.
–The user has received instruction from a
STIHL servicing dealer or other experi‐
enced user before working with the trim‐
mer for the first time.
–The user must not be under the influence
of alcohol, medication or drugs.
► If you have any queries: Contact a STIHL
servicing dealer for assistance.
■ The trimmer’s ignition system produces an
electromagnetic field. This field may interfere
with some pacemakers. This can result in seri‐
ous or fatal injuries.
►If the user has a pacemaker: Make sure the
pacemaker is not affected.
4.4 Clothing and equipment
WARNING
■Long hair can be drawn into the brushcutter
during operation. This may result in serious
injury to the user.
►Tie up and confine long hair above your
shoulders.
■ Objects can be thrown at high speed during
operation. This may result in injury to the user.
► Wear close-fitting safety glasses.
Suitable safety glasses are tested in
accordance with EN 166 or national
regulations and available commer‐
cially with the corresponding mark‐
ing.
►Wear face protection.
► Wear long trousers made from resistant
material.
■ Noise is generated during operation. Noise
can damage your hearing.
► Wear ear protection.
■ Falling objects can cause head injuries.
► If objects are likely to fall while work‐
ing: wear a hard hat.
■ Dust can be whipped up during operation.
Whipped up dust can damage the respiratory
passages and cause allergic reactions.
►If dust is generated: Wear a dust respirator
mask.
■ Inappropriate clothing can snag on wood,
brush or the brushcutter. Users not wearing
suitable clothing are at risk of serious injury.
►Wear close-fitting clothing.
► Remove scarves and jewelry.
■ The user may come into contact with the rotat‐
ing cutting attachment during operation. This
may result in serious injury to the user.
►Wear robust footwear.
► If you are using a metal cutting
attachment: Wear steel-toed safety
boots.
► Wear long trousers made from resistant
material.
■ When mounting and dismounting the cutting
attachment and during cleaning or mainte‐
nance, the user may come into contact with
the sharp edges of the cutting attachment or
the crosscut blade. This may result in injury to
the user.
► Wear work gloves made from resist‐
ant material.
■ Wearing unsuitable footwear may cause the
user to slip. This may result in injury to the
user.
►Wear sturdy, closed-toed footwear with high-
grip soles.
English 4 Safety Precautions
6 0458-856-0121-A. VA0.B21.

4.5 Working Area and Surround‐
ings
WARNING
■Bystanders, children and animals are not
aware of the dangers of the brushcutter or fly‐
ing debris. This may result in serious injury to
bystanders, children and animals and damage
to property.
15m (50ft)
► Do not allow bystanders,
children or animals within 15
meters of the work area.
► Maintain a clearance of 15 meters from
objects.
► Do not leave the brushcutter unattended.
► Make sure that children cannot play with the
brushcutter.
■ Hot exhaust gas is emitted through the muffler
while the engine is running. Hot exhaust gas
can ignite easily flammable materials and
cause a fire.
►Keep exhaust gas well away from easily
flammable materials.
4.6 Safe Condition
4.6.1 Brushcutter
The brushcutter is in a safe condition if the fol‐
lowing points are observed:
–The brushcutter is not damaged.
–There is no fuel leaking from the trimmer.
–The fuel tank cap is closed.
–The brushcutter is clean.
–The controls function properly and have not
been modified.
–A combination of cutting attachment and
deflector recommended in this user manual is
mounted.
–The cutting attachment and deflector are prop‐
erly mounted.
–Genuine STIHL accessories for this brushcut‐
ter are fitted.
–The accessories are correctly attached.
–All accessible screws and fastening parts are
firmly tightened.
WARNING
■If not in safe condition, components may no
longer operate correctly, safety devices may
be disabled and fuel leakage may occur. This
may result in serous or fatal injury to people.
►Work only with an undamaged brushcutter.
► If fuel is leaking from the trimmer: Do not use
the trimmer and contact a STIHL dealer for
assistance.
►Close the fuel tank cap.
► If the brushcutter is dirty: Clean the brushcut‐
ter.
► Never attempt to modify your brushcutter.
Exception: Mounting one of the combinations
of cutting attachment and deflector recom‐
mended in this user manual.
►If the controls do not function properly: Do
not use your brushcutter.
► Fit genuine STIHL accessories for this brush‐
cutter.
► Mount the cutting attachment and deflector
as described in this user manual.
► Attach accessories as described in this User
Manual or in the User Manual for the acces‐
sories.
►Tighten loose screws and fastening parts.
► Never insert objects in the openings of the
brushcutter.
► Replace worn or damaged labels.
► If you have any doubts, be sure to consult a
STIHL dealer.
4.6.2 Deflector
The deflector is in a safe condition if the following
points are observed:
–The deflector is not damaged.
–The screws on the guard are tightened to the
correct torque.
–If the guard is used for mowing heads: The
line limiter blade is correctly installed.
WARNING
■If not in safe condition, components may no
longer operate correctly and safety devices
may be disabled. This may result in serious
injury to the user.
►Work only with an undamaged deflector.
► Tighten the screws on the guard to the cor‐
rect tightening torque, 6.2.
► If the guard for mowing heads is used: Work
with a properly attached cut-off blade.
► If you have any doubts, be sure to consult a
STIHL dealer.
4.6.3 Mowing Head
The mowing head is in a safe condition if the fol‐
lowing points are observed:
–The mowing head is not damaged.
–The mowing head is not jammed.
–The mowing lines are properly installed.
–The wear limits are not exceeded.
WARNING
■If they are in an unsafe condition, parts of the
mowing head or mowing lines may come off
4 Safety Precautions English
0458-856-0121-A. VA0.B21. 7

and be ejected at high speed. They may
cause serious injury to persons.
► Work only with an undamaged mowing head.
► Never use metal objects in place of the nylon
mowing lines.
► Observe and remain inside the wear limits.
► If you have any doubts, be sure to consult a
STIHL dealer.
4.6.4 Metal cutting attachment
The metal cutting attachment is in a safe condi‐
tion if the following points are observed:
–Metal cutting attachment and mounting hard‐
ware are undamaged.
–Metal cutting attachment is not warped.
–Metal cutting attachment is properly mounted.
–Metal cutting attachment is correctly sharp‐
ened.
–Cutting edges of the metal cutting attachment
have no burrs.
–The wear limits are not exceeded.
–If a metal cutting attachment not manufactured
by STIHL is used, it must not be heavier,
thicker, of a different shape, of a lower quality,
or larger in diameter than the largest metal
cutting attachment approved by STIHL.
WARNING
■ If it is not in an safe condition, parts of the
metal cutting attachment may come off and be
thrown at high speed. They may cause serious
injury to persons.
►Never work with a damaged metal cutting
attachment or damaged mounting hardware.
► Sharpen the metal cutting attachment cor‐
rectly.
► Deburr the cutting edges with a file.
► Have the metal cutting attachment balanced
by a STIHL servicing dealer.
► Observe and remain inside the wear limits.
► Use a metal cutting attachment specified in
these instructions for use.
► If you have any doubts, be sure to consult a
STIHL dealer.
4.7 Fuel Mixture and Refueling
WARNING
■This trimmer requires a fuel mixture of gaso‐
line and two-stroke engine oil. Fuel mixture
and gasoline are extremely flammable. If fuel
mixture or gasoline make contact with open
fire or hot objects, they can cause a fire or
explosion. This can result in serious or fatal
injuries and damage to property.
►Protect fuel mixture and gasoline from heat
and fire.
► Do not spill fuel mixture and gasoline.
► If fuel has been spilled: Wipe up the fuel with
a cloth and do not attempt to start the engine
until all parts of the trimmer and the area
around it are dry.
►Do not smoke.
► Never refuel near a fire.
► Shut off the engine and allow it to cool down
before refueling.
► Start the engine at least 3 meters from the
fueling spot, outdoors only.
■ Inhaling fuel fumes and gasoline fumes can
have toxic effects.
► Avoid inhaling fuel fumes or gasoline fumes.
► Refuel in a well-ventilated location.
■ The trimmer becomes hot during operation.
The fuel expands and excess pressure can
build up in the tank. Fuel can escape as a
spray when the fuel tank cap is opened. The
escaping fuel can ignite. This can result in
serious injuries.
►Allow the trimmer to cool down first and then
open the tank cap carefully.
■ Clothing that has been in contact with fuel or
gasoline is more easily flammable. This can
result in serious or fatal injuries and damage
to property.
►If your clothing comes into contact with fuel
or gasoline: Change your clothing.
■ Fuel mix, gasoline and two-stroke engine oil
can harm the environment.
► Do not spill fuel, gasoline or two-stroke
engine oil.
► Dispose of fuel mix, gasoline and two-stroke
engine oil in accordance with local regula‐
tions and environmental requirements.
■Fuel, gasoline or two-stroke engine oil can
cause irritation if they come into direct contact
with the skin or eyes.
►Avoid contact with fuel, gasoline and two-
stroke engine oil.
► In case of contact with the skin: Wash affec‐
ted areas with plenty of water and soap.
► In case of contact with the eyes: Rinse eyes
with plenty of water for at least 15 minutes
and seek medical advice.
■The trimmer’s ignition system produces
sparks. Unconfined sparks may cause a fire or
an explosion in an easily combustible or explo‐
sive environment. This can result in serious or
fatal injuries and damage to property.
►Use the spark plugs described in this instruc‐
tion manual.
► Insert and tighten down the spark plug.
English 4 Safety Precautions
8 0458-856-0121-A. VA0.B21.

► Connect the spark plug boot and press it
down firmly.
■ The trimmer can be damaged if it is run on a
fuel mixture consisting of unsuitable gasoline
or an unsuitable two-stroke engine oil or if an
incorrect mix ratio of gasoline and two-stroke
engine oil is used.
►Mix the fuel as described in this instruction
manual.
■ The mixture of gasoline and two-stroke engine
oil can separate if it is stored for a long period.
The trimmer can be damaged if it is used with
a fuel mix that has become separated.
►Before refueling the trimmer: Thoroughly mix
the fuel.
► Use a mixture of gasoline and two-stroke
engine oil that is not older than 30 days
(STIHL MotoMix: 2 years).
4.8 Working
WARNING
■ If the engine is not started properly, the user
may lose control of the trimmer. This may
result in serious injury to the user.
►Start the engine as described in this instruc‐
tion manual.
► If the cutting attachment is touching the
ground or objects: Do not start the engine.
■If the start flap lever is in the position when
the engine is started, the engine speed is
higher than the idle speed and the cutting
attachment can rotate as soon as the engine
is running. This may result in serious injury to
the user.
►Do not touch the cutting attachment.
► Start the engine as described in this instruc‐
tion manual.
■ In certain situations, the user may no longer
be able to concentrate on their work. The user
can lose control of the trimmer, stumble or fall
and be seriously injured.
►Keep calm and plan your work.
► If light and visibility are poor: Do not use your
trimmer.
► Operate the trimmer alone.
► Keep the cutting attachment close to the
ground.
► Watch out for obstacles.
► Work standing on the ground and keep your
balance.
► If you start feeling fatigue: Take a break.If
you start feeling fatigue: Take a break.
■ Exhaust gas is produced when the engine is
running. Breathing in exhaust gas can have
toxic effects.Breathing in exhaust gas can
have toxic effects.
► Avoid inhaling exhaust gas.
► Operate the trimmer is a well ventilated loca‐
tion.
► In the event of nausea, headache, visual dis‐
turbances, problems with hearing or dizzi‐
ness: Stop work and seek medical advice.
■The user’s ability to hear and assess noises is
restricted when wearing hearing protection
with the engine running.
►Keep calm and plan your work.
■ In case of working with the trimmer and the
start flap lever is in the position , the user
cannot work with the power brush in a control‐
led manner. This may result in serious injury to
the user.
►Check that the choke lever is in position
during operation.
► Start the engine as described in this instruc‐
tion manual.
■ The rotating cutting attachment can cut the
user. This may result in serious injury to the
user.
►Do not touch the rotating cutting attachment.
► If the cutting attachment is blocked by an
object: Shut off the engine. before clearing
the jam.
■The machine can be damaged if you open the
throttle while the cutting attachment is blocked
by an object.
►Shut off the engine. before clearing the jam.
■ If the behavior of the trimmer changes during
operation or feels unusual, it may no longer be
in a safe condition. This may result in serious
injury to people and damage to property.
►Stop work and consult a STIHL servicing
dealer.
■ Trimmer vibrations may occur during opera‐
tion.
► Wear gloves.
► Take breaks.
► If signs of a circulatory disturbance occur:
Consult a doctor.
■ If the cutting attachment makes contact with a
foreign object during operation, the object or
parts of it may be thrown at high speed. Per‐
sons may be injured or property damaged.
►Remove foreign objects from the working
area.
■ If the rotating metal cutting attachment makes
contact with a hard object, sparks may occur
4 Safety Precautions English
0458-856-0121-A. VA0.B21. 9

and the cutting attachment may be damaged.
Sparks can cause fires in a flammable envi‐
ronment. Persons may be seriously or fatally
injured and property may be damaged.
►Do not use the chain saw in a flammable
environment.
► Make sure the metal cutting attachment is in
a safe condition.
■ Note that the cutting attachment continues to
rotate for a short period after you release the
trigger. They may cause serious injury to per‐
sons.
►Wait until the cutting attachment comes to a
complete stop.
■ In an emergency, the user may start to panic
and forget to take off the carrying system. This
may result in serious injury to the user.
►Practice taking off the carrying system.
4.9 Reactive Forces
0000-GXX-3025-A1
Kickout can be caused for the following reasons:
–The shaded area or the black area of the rotat‐
ing metal cutting attachment comes into con‐
tact with a solid object and is suddenly braked.
–The rotating metal cutting attachment gets
pinched in the cut.
The risk of kickout is greatest in the black area.
WARNING
■These situations can abruptly decelerate or
stop rotation of the cutting attachment and
cause the cutting attachment to be thrown to
the right or in the direction of the user (black
arrow). The user can lose control of the trim‐
mer. This can result in serious or fatal injuries.
►Hold the trimmer firmly with both hands.
► Use the working techniques described in this
instruction manual.
► Do not use the black area for cutting.
► Use a combination of cutting attachment,
deflector and carrying system recommended
in this instruction manual.
►Sharpen the metal cutting attachment cor‐
rectly.
► Cut with the motor running at full speed.
4.10 Transporting
WARNING
■The gearbox can get hot during operation.
There is a risk of burn injuries.
► Do not touch a hot gearbox.
■ The trimmer may turn over or shift during
transport. This may result in personal injuries
and damage to property.
►Shut off the engine.
► If a metal cutting attachment is mounted: Fit
the transport guard.
► Secure the trimmer with lashing straps or a
net to prevent it turning over and moving.
■ The muffler and engine may be hot after a
period of operation. There is a risk of burn
injuries.
►Carry the trimmer properly balanced by the
drive tube with the cutting attachment behind
you.
4.11 Storing
WARNING
■ Children are not aware of and cannot assess
the dangers of a trimmer and can be seriously
injured.
►Shut off the engine.
► If a metal cutting attachment is mounted: Fit
the transport guard.
► Store the trimmer out of the reach of chil‐
dren.
■ Dampness can corrode the electrical contacts
on the trimmer and metal components. This
can damage the trimmer.
►Store the trimmer in a clean and dry condi‐
tion.
4.12 Cleaning, Maintenance and
Repair
WARNING
■The cutting attachment can start rotating unin‐
tentionally if the engine is running during
cleaning, maintenance or repair operations.
This may result in serious injury to people and
damage to property.
►Shut off the engine.
■ The muffler and engine may be hot after a
period of operation. This can result in burn
injuries.
►Wait until the muffler and engine cool down.
■ The gear housing can get hot during opera‐
tion. There is a risk of burn injuries.
English 4 Safety Precautions
10 0458-856-0121-A. VA0.B21.

► Do not touch a hot gear housing.
■ Aggressive cleaning agents, a water jet or
pointed objects can damage the trimmer,
deflector or the cutting attachment. If the trim‐
mer, deflector and cutting attachment are not
cleaned correctly, components may no longer
function properly or safety devices may be
rendered inoperative. They may cause serious
injury to persons.
► Clean the trimmer, deflector and cutting
attachment as described in this instruction
manual.
■If the trimmer, deflector and cutting attachment
are not serviced or repaired correctly, compo‐
nents may no longer function properly or
safety devices may be rendered inoperative.
This may result in serous or fatal injury to peo‐
ple.
►Do not attempt to service or repair the trim‐
mer or deflector.
► If the trimmer or the deflector require servic‐
ing or repairs: Contact your STIHL servicing
dealer for assistance.
►Maintain the cutting attachment as described
in the User Manual supplied with the cutting
attachment being used or on the cutting
attachment’s packaging.
■The user can be cut by the sharp cutting
edges while cleaning or maintaining cutting
attachments. This may result in injury to the
user.
► Wear work gloves made from resist‐
ant material.
5 Preparing Trimmer for
Operation
5.1 Preparing the Brushcutter for
Operation
The following steps must be performed before
commencing work:
► Ensure that the following components are in
safe condition:
–Brushcutter, 4.6.1.
–Deflector, 4.6.2.
–Mowing head or metal cutting attachment,
4.6.3 or 4.6.4.
►Clean the brushcutter, 15.1.
►Mount the bike handle, 6.1.
► Select combination of cutting attachment,
deflector and carrying system, 20.
►Mount the deflector, 6.2.
► Mount mowing head or metal cutting attach‐
ment, 6.3.1 or 6.4.
►Fuel the trimmer, 8.2.
►Fit and adjust the carrying system, 7.1.
►Adjust the bike handle, 7.2.
►Balance the brushcutter, 7.3.
►Check the controls, 10.1.
► If you cannot carry out this work: Do not use
your brushcutter and contact your STIHL
dealer for assistance.
6 Assembling the Trimmer
6.1 Mounting the Bike Handle
► Shut off the engine.
7
6
1
2
3
8
2
4
5
0000097393_001
► Open the clamp of the toggle screw (1) and
turn it counterclockwise until the handle tube
(2) is only slightly clamped.
► Insert the spring (5) from below into the lower
clamp molding (4).
► Place the clamp moldings (3 and 4) on the
shaft and insert the wing screw (1).
► Swing the handlebar (2) up.
► Tighten the toggle screw (1) and fold the
bracket shut.
► Remove the screw (6).
► Position the control handle (8) on the handle‐
bar (2), trigger facing the gear housing, and
line up the hole in the control handle with the
hole in the handlebar.
When doing so, do not twist the operating han‐
dle (8).
► Fit the nut (7).
► Insert and tighten down the screw (6) firmly.
The bike handle can be left on the shaft.
6.2 Removing the Deflector and
the Limit Stop
6.2.1 Attaching guard for mowing heads,
metal cutting tools and stop
► Shut off the engine.
5 Preparing Trimmer for Operation English
0458-856-0121-A. VA0.B21. 11

1
2
0000097394_001
► Position the guard (1) on the gear housing.
► Insert the screws (2) and tighten them down to
a torque of 10 Nm.
6.2.2 Removing deflector for mowing heads,
metal cutting attachments and limit
stop
► Shut off the engine.
► Take out screws.
► Remove guard.
6.2.3 Mounting deflector for shredder blade
An additional holder is required on the shaft to
attach the deflector. The holder is attached to the
shaft with special screws and special tools.
► Shut off the engine.
► If the holder for the guard has not yet been fit‐
ted to the shaft: Have the holder fitted by a
STIHL dealer.
3
3
3
3
4
2
1
0000097395_001
► Place the guard (1) on the holder (2) so that
the curved side faces inwards towards the
gear unit housing.
► Insert the screws (3) and tighten them down to
a torque of 10 Nm.
► Press plugs (4) into the threaded holes on the
gear unit housing.
The threaded holes are protected from dirt.
6.2.4 Dismantling the guard for shredder
blades
► Shut off the engine.
► Take out screws.
► Remove guard.
► Pull the plug out of the threaded holes on the
gear unit housing and press it into the threa‐
ded holes of the bracket.
The threaded holes of the bracket are protec‐
ted against dirt.
6.3 Mounting and Removing the
Mowing Head
6.3.1 Mounting the Mowing Head
► Shut off the engine.
1 1
2
3
4
4
0000097396_001
► Place the thrust plate (2) on the shaft (3) so
that its smaller diameter faces up.
► Fit the mowing head (1) on the shaft (3) and
turn it counterclockwise by hand.
► Insert the stop pin (4) in the bore up to the limit
stop and hold it depressed.
► Turn the mowing head (1) counterclockwise
until the stop pin (4) engages in position.
The shaft (3) is now blocked.
► Tighten down the mowing head (1) firmly by
hand.
► Remove the stop pin (4).
6.3.2 Removing the Mowing Head
► Shut off the engine.
► Insert the stop pin in the bore as far as stop
and hold it depressed.
► Rotate the mowing head until the stop pin
engages in position.
The shaft is now blocked.
► Unscrew the mowing head clockwise.
► Remove the thrust plate.
► Remove stop pin.
6.4 Removing and Installing Metal
Cutting Attachment
6.4.1 Mounting grass cutting blade, brush
knife or circular saw blade
► Shut off the engine.
English 6 Assembling the Trimmer
12 0458-856-0121-A. VA0.B21.

7
5
4
3
2
1
6
0000097397_001
► Place the thrust plate (5) on the shaft (6) so
that its smaller diameter faces up.
► Place the metal cutting attachment (4) on the
thrust plate (5). If you are fitting a circular saw
blade or a grass cutting blade with more than
4 cutting edges: Its cutting edges must face in
the same direction as the arrow on the deflec‐
tor.
► Place the thrust washer (3) on the metal cut‐
ting attachment (4) so that its raised side faces
up.
► Place the rider plate (2) on the thrust washer
(3) so that its closed side faces up.
► Insert the stop pin (7) in the bore up to the limit
stop and hold it depressed.
► Rotate the metal cutting attachment (4) coun‐
terclockwise until the stop pin (7) engages in
position.
The shaft (6) is now blocked.
► Fit the nut (1) counterclockwise and tighten it
down firmly.
► Remove the stop pin (7).
6.4.2 Mounting Brush Knives or Shredder
Blades
► Shut off the engine.
2
1
3
7
5
6
4
0000097398_001
► Place the thrust plate (5) on the shaft (6) so
that its smaller diameter faces up.
► Place the metal cutting attachment (4) on the
thrust plate (5). If a shredder bladee is used:
Align cutting edges so that they point away
from the gear unit in the direction of the nut
(1).
► Place the thrust washer (3) on the metal cut‐
ting attachment (4) so that its raised side faces
up.
► Place the protective ring (2) on the thrust
washer (3) so that the opening points
upwards.
► Insert the stop pin (7) in the bore as far as
stop and hold it depressed.
► Rotate the metal cutting attachment (4) coun‐
terclockwise until the stop pin (7) engages in
position.
The shaft (6) is now blocked.
► Fit the nut (1) counterclockwise and tighten it
down firmly.
► Remove the stop pin (7).
6.4.3 Removing the metal cutting attach‐
ment
► Shut off the engine.
► Insert the stop pin in the bore up to the limit
stop and hold it depressed.
► Rotate the metal cutting attachment clockwise
until the stop pin engages in position.
The shaft is now blocked.
► Unscrew the mounting nut clockwise.
► Remove the fastening parts, metal cutting tool
and pressure plate.
► Remove the stop pin.
6 Assembling the Trimmer English
0458-856-0121-A. VA0.B21. 13

7 Adjusting Trimmer for User
7.1 Fitting and Adjusting the Full
Harness
1
2
0000097399_001
► Putting on the Full harness (1).
► Adjust the full harness (1) so that the carabi‐
ner (2) is about a hand’s width below your
right hip.
7.2 Adjusting the Bike Handle
The bike handle can be set to different positions
to suit the height and reach of the user.
► Shut off the engine.
► Hook the brushcutter from the carrying strip
into the carabiner of the carrying system.
1
2
0000097400_001
► Loosen the wing screw (1).
► Swing the bike handle (2) to the required posi‐
tion.
► Tighten down the wing screw (1) firmly.
7.3 Balancing the Brushcutter
The unit is balanced differently depending on the
cutting attachment used.
If a mowing head, grass cutting blade, a brush
knife or a shredder blade is fitted:
0000-GXX-7836-A0
The cutting attachment should rest lightly on the
ground.
If a circular saw blade is fitted:
0000-GXX-7808-A0
The saw blade must hover at a height of about
20 cm above the ground.
► Shut off the engine.
1
2
0000097031-001
► Hook the carrying strip (2) onto the carabi‐
ner (1).
► Wait for brushcutter to stop swinging.
► Check the position of cutting attachment. If it
needs adjustment: Hook the snap hook (1)
into another hole in the hole bar (2) and let it
swing out again.
8 Mixing Fuel and Refueling
the Brushcutter
8.1 Mixing fuel
The fuel required for this trimmer is a mixture of
gasoline and two-stroke engine oil, in a mixing
ratio of 1:50.
STIHL recommends you use STIHL MotoMix.
English 7 Adjusting Trimmer for User
14 0458-856-0121-A. VA0.B21.

If you mix the fuel yourself, use only STIHL two-
stroke engine oil or another high-performance
engine oil in accordance with JASO FB, JASO
FC, JASO FD, ISO-L-EGB, ISO-L-EGC or ISO-L-
EGD.
STIHL specifies STIHL HP Ultra two-stroke
engine oil or an equivalent high-performance
engine oil in order to maintain emission limits
over the machine’s service life.
► Make sure that the octane number of the gas‐
oline is at least 90 RON and the ethanol con‐
tent is not more than 10%.
► Make sure the two-stroke engine oil you are
using meets the requirements.
► Depending on the desired amount of fuel,
determine the correct amounts of two-stroke
engine oil and gasoline in a mixing ratio of
1:50. Examples for fuel mixes:
–20 ml Two-stroke engine oil, 1 l gasoline
–60 ml Two-stroke engine oil, 3 l gasoline
–100 ml Two-stroke engine oil, 5 l gasoline
► Pour two-stroke engine oil into a clean
approved fuel canister first and then add gaso‐
line.
► Stir the fuel before topping up.
8.2 Fueling the Trimmer
► Shut off the engine.
► Place your trimmer on a level surface so that
the fuel tank cap faces up.
► Use a damp cloth to clean the tank cap and
the area around it.
0000-GXX-4727-A0
► Turn the tank cap counterclockwise until it can
be removed.
► Remove the fuel tank cap.
NOTICE
■ Bright light, sunlight and extreme tempera‐
tures can cause the fuel mix to separate much
faster. The trimmer can be damaged if it is
used with a fuel mix that has become separa‐
ted.
►Thoroughly mix the fuel.
► Do not use fuel mix that has been stored for
more than 30 days.
► Fill the tank to within no more than 15 mm
of the brim, taking care not to spill any fuel.
0000-GXX-4728-A0
► Fit the tank cap on the tank opening.
► Turn the tank cap clockwise and tighten it
down firmly by hand.
The fuel tank is closed.
9 Starting and Stopping the
Engine
9.1 Starting the engine
► Place the trimmer on a level surface so that
the cutting attachment does not touch the
ground or other objects.
► Remove the transport guard.
3
4
1
2
0000097401_001
► Depress the manual fuel pump (1) at least 5
times.
► If the engine is warm: Leave the choke lever
(2) in position .
► If the engine is at ambient temperature: Push
in the choke lever (2) at the edge and set it in
position .
9 Starting and Stopping the Engine English
0458-856-0121-A. VA0.B21. 15

0000-GXX-4729-A0
► Press the trimmer against the ground with
your left hand.
► Pull the starter grip slowly with your right hand
until you feel it engage.
► Pull the starter grip quickly and allow the
starter rope to rewind several times until the
engine runs.
►If the choke lever (2) is in the position :
briefly press the throttle lever lockout (3) and
the throttle trigger (4).
The choke lever (2) springs to position . The
engine runs at idling speed.
► If the cutting attachment rotates when the
engine is idling: Rectify the malfunction.
Throttle cable adjustment is not correct.
► If the engine does not start: Move the choke
lever (2) to position and try again to start
the engine.
9.2 Shut off the engine
2
3
1
0000097402_001
► Release the throttle trigger (1) and throttle trig‐
ger lockout (2).
The cutting attachment comes to a standstill.
► Depress the stop switch (3).
The engine stops.
10 Testing the Trimmer
10.1 Checking the controls
Throttle trigger lockout and throttle trigger
► Shut off the engine.
► Attempt to pull the trigger without depressing
the lockout lever.
► If the trigger can be pulled: Do not use your
trimmer and contact your STIHL dealer for
assistance.
The throttle trigger lockout is defective.
► Press the throttle trigger lockout and keep
pressed.
► Depress the throttle trigger.
► Release the throttle trigger and throttle trigger
lockout.
► If the trigger or trigger lockout is stiff or does
not spring back to the idle position: Do not use
your trimmer and contact your STIHL dealer
for assistance.
Trigger or trigger lockout is faulty.
Throttle cable adjustment
► Start the engine.
► Attempt to pull the trigger without depressing
the lockout lever.
► If the engine accelerates: Adjust the throttle
cable.
Throttle cable adjustment is not correct.
Shut off the engine
► Start the engine.
► Depress the stop switch.
The engine stops.
► If the engine does not stop:
►Move the choke lever to position .
The engine stops.
► Do not use your trimmer and contact a
STIHL servicing dealer for assistance.
The brushcutter is defective.
11 Operating the Trimmer
11.1 Winter Operation
The carburetor may ice up if the engine is oper‐
ated at temperatures below +10°C. The shutter
must be set to the winter mode so that carburetor
is additionally heated by warm air from around
the engine.
NOTICE
■ The engine may overheat if is operated in the
winter mode at temperatures above +10°C.
► Change setting to summer mode.
► Shut off the engine.
English 10 Testing the Trimmer
16 0458-856-0121-A. VA0.B21.

1
2
0000-GXX-8720-A0
1
2
3
► Take out the screw (1).
► Pull out the shutter (2).
► Hold the shutter (2) so the snowflake points to
the mark (3).
► Fit the shutter.
► Fit the screw (1).
11.2 Summer Operation
The shutter must be set to summer mode when
working at temperatures above +10°C.
► Shut off the engine.
1
1
2
2
3
0000-GXX-8721-A0
► Take out the screw (1).
► Pull out the shutter (2).
► Hold the shutter (2) so the sun points to the
mark (3).
► Fit the shutter.
► Fit the screw (1).
11.3 Calibrating the trimmer
The trimmer adjusts itself automatically for opti‐
mum performance during operation. Calibration
enables the trimmer to be adjusted faster for
optimum performance.
► Remove mowing head or metal cutting attach‐
ment.
This allows the trimmer to reliably adjust to the
optimum performance.
► If the outside temperature is below -10°C or
the engine is cold:
► Start the engine.
► Warm up the engine by opening and closing
the throttle for about 1 minute.
► Shut off the engine.
1
min
AB C
s> 30 s30-60 s
0000-GXX-3825-A0
►Move the choke lever to position .
► Start the engine without depressing the throttle
trigger.
The engine runs and the choke lever remains
in position .
► Run the engine for at least 30 seconds but no
more than 60 seconds (A) without depressing
the throttle trigger.
NOTICE
■ The calibration process is aborted if the throt‐
tle trigger is released before the trigger is
properly calibrated. It is then necessary to
restart the calibration process.
►Keep the throttle trigger fully depressed.
NOTICE
■ The trimmer can be incorrectly calibrated if the
throttle trigger is not kept fully depressed dur‐
ing calibration. This can damage the brushcut‐
ter.
►Keep the throttle trigger fully depressed.
► Depress the throttle trigger for at least 30
seconds (B) and hold it in that position.
The engine accelerates and the trimmer is
calibrated. The engine speed fluctuates and
increases perceptibly during calibration.
► If the engine stalls: Make another attempt to
calibrate the trimmer.
► If the engine stops repeatedly: Do not use
your trimmer and contact your STIHL servicing
dealer for assistance.
The brushcutter is defective.
► As soon as the engine speed drops noticeably
(C): Release the throttle trigger.
The engine runs at idling speed. The brushcut‐
ter is calibrated and ready for use.
11 Operating the Trimmer English
0458-856-0121-A. VA0.B21. 17

11.4 Holding and Controlling the
Brushcutter
1
2
0000097031-001
► Hook the carrying strip (2) onto the carabi‐
ner (1).
0000-GXX-7850-A0
► Hold the brushcutter firmly with your right hand
on the control handle – wrap your thumb
around the handle.
► Hold the brushcutter with your the left hand on
the left grip in such a way that your thumb
encloses the handle.
11.5 Mowing
The cutting height is determined by the distance
of the cutting attachment from the ground.
A B
0000-GXX-4731-A2
Mowing with a mowing head (A)
► Swing the brushcutter steadily back and forth
in an arc.
► Move forward slowly in a controlled manner.
Mowing with a grass cutting blade or brush
knife (B)
► Mow with the left-hand side on the metal cut‐
ting attachment.
► Move forward slowly in a controlled manner.
11.6 Thinning with a brush knife or
shredder blade
0000097404_001
► Dip the metal cutting attachment into the
thicket from above.
► Do not lift metal cutting tool above waist
height.
11.7 Saws with a circular saw blade
0000-GXX-3042-A0
► Support the left side of the deflector against
the stem.
► Cut through the stem at full speed.
► A safety distance of at least 2 tree lengths to
the next work area.
11.8 Adjusting Nylon Line
11.8.1 Line Feed on AutoCut Mowing Head
► Tap the rotating mowing head on the ground.
About 30 mm of fresh nylon line is advanced.
The line limiting blade in the deflector trims the
mowing lines to the correct length.
1
2
0000-GXX-4037-A1
Automatic feed does not operate if the mowing
lines are shorter than 25 mm.
► Shut off the engine.
English 11 Operating the Trimmer
18 0458-856-0121-A. VA0.B21.

► Depress the spool (1) on the mowing head
and hold it depressed.
► Pull out the mowing lines (2).
► If the mowing lines (2) cannot be pulled out to
the required length: Replace the spool (1) or
the mowing lines (2).
The spool is empty.
12 After Finishing Work
12.1 When Work is Finished
► Shut off the engine.
► Allow trimmer to cool down.
► If the brushcutter is wet: Allow the brushcutter
to dry.
► Clean the brushcutter.
► Clean the deflector.
► Clean the cutting attachment.
► If a metal cutting attachment is mounted: Fit
the matching transport guard.
13 Transporting
13.1 Transporting the Trimmer
► Shut off the engine.
► If a metal cutting attachment is mounted: Fit
the matching transport guard.
Carrying the trimmer
► Carry the trimmer properly balanced by the
drive tube with the cutting attachment behind
you.
Transporting the trimmer in a vehicle
► Secure the trimmer to prevent turnover and
movement.
14 Storing
14.1 Storing the Brushcutter
► Shut off the engine.
► If a metal cutting attachment is mounted: Fit
the matching transport guard.
1
90°
2
0000097476_001
► Loosen the wing screw (1) and unscrew it until
the handlebar (2) can be rotated.
► Turn the handlebar (2) clockwise through 90°
and fold it down.
► Tighten down the wing screw (1) firmly.
► Ensure that the following conditions are met
when storing the brushcutter:
–The brushcutter is out of the reach of chil‐
dren.
–The brushcutter is clean and dry.
15 Cleaning
15.1 Cleaning the Trimmer
► Shut off the engine.
► Allow trimmer to cool down.
► Clean the trimmer with a damp cloth or STIHL
resin solvent.
► Clean cooling air slots with a soft brush.
15.2 Cleaning the Deflector and Cut‐
ting Attachment
► Shut off the engine.
► Clean the deflector and cutting attachment
with a damp cloth or a soft brush.
15.3 Cleaning the Spark Plug
► Shut off the engine.
► Allow trimmer to cool down.
2
1
4
3
0000097405_001
► Turn screw (1) counterclockwise.
► Lift the cover (2) and push it backwards.
► Pull off the spark plug boot (3).
► If the area around the spark plug (4) is soiled:
Clean it with a damp cloth (4).
► Unscrew the spark plug (4).
► Clean the spark plug (4) with a damp cloth.
► If the spark plug (4) is corroded: Install a new
spark plug (4).
► Insert and tighten down the spark plug (4)
firmly.
► Press the spark plug boot (3) firmly home.
► Install cover (2) and tighten screw (1).
16 Maintenance
16.1 Maintenance Intervals
The maintenance intervals are dependent on the
environmental and operating conditions. STIHL
12 After Finishing Work English
0458-856-0121-A. VA0.B21. 19

recommends the following maintenance inter‐
vals:
After every 25 hours of operation
► Lubricate the gearbox.
After every 100 hours of operation
► Install a new spark plug.
Monthly
► Have fuel tank cleaned by a STIHL servicing
dealer.
► Have pickup body (filter) in fuel tank cleaned
by a STIHL servicing dealer.
Every 12 months
► Have pickup body (filter) in fuel tank replaced
by a STIHL servicing dealer.
16.2 Lubricating the Gearbox
2
1
0000-GXX-3044-A0
► Remove the screw plug (2).
► If no grease can be seen on the end of the
screw plug (2):
► Screw the tube (1) of STIHL gear grease
into the filler hole.
► Squeeze 5 g of STIHL gear grease into the
gear housing.
► Unscrew the tube (1) of STIHL gear grease.
► Refit and tighten down the screw plug (2)
firmly.
► Run the trimmer for 1 minute.
STIHL gear grease is distributed evenly.
16.3 Adjusting the throttle cable
► Shut off the engine.
2
3
1
0000097406_001
► Totally press throttle trigger lockout (1) and
throttle trigger (2) and keep pressed.
► Turn screw (3) clockwise until resistance is
felt.
► Continue turning screw (3) clockwise by half a
turn.
16.4 Sharpening and Balancing a
Metal Cutting Attachment
Correctly sharpening and balancing metal cutting
attachments requires a lot of practice.
STIHL recommends you have metal cutting
attachments resharpened and balanced by a
STIHL servicing dealer.
► Sharpen the metal cutting attachment as
described in the instructions and on the pack‐
aging supplied with the cutting attachment you
are using.
17 Repairing
17.1 Repairing the Trimmer and
Cutting Attachment
The trimmer and cutting attachment cannot be
repaired by the user.
► If the trimmer or cutting attachment is dam‐
aged: Do not use your trimmer or cutting
attachment and contact your STIHL servicing
dealer.
18 Troubleshooting
18.1 Troubleshooting Trimmer
Most problems can be attributed to the same cause.
► Carry out the following measures:
► replace the air filter.
► Clean or replace the spark plug.
► Adjust saw for winter or summer operation.
► If the problem continues: Carry out the measured listed below.
English 17 Repairing
20 0458-856-0121-A. VA0.B21.