Stihl GS 461 User manual

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STIHL GS 461
WARNING
Read Instruction Manual thoroughly
before use and follow all safety
precautions – improper use can
cause serious or fatal injury.
ADVERTENCIA
Antes de usar la máquina lea y siga
todas las precauciones de
seguridad dadas en el manual de
instrucciones – el uso incorrecto
puede causar lesiones graves o
mortales.
Instruction Manual
Manual de instrucciones

Instruction Manual
1 - 42
Manual de instrucciones
43 - 88

Original Instruction ManualPrinted on chlorine-free paper
Printing inks contain vegetable oils, paper can be recycled.
© ANDREAS STIHL AG & Co. KG, 2015 0458-761-8621-A. VA6.D15. 0000006302_009_GB
GS 461
English
1
{This instruction manual is protected by copyright. All rights reserved, especially the rights to reproduce, translate and process
with electronic systems.
Contents
Allow only persons who fully understand
this manual to operate your concrete
cutter.
To receive maximum performance and
satisfaction from your STIHL concrete
cutter, it is important that you read,
understand and follow the safety
precautions and the operating and
maintenance instructions in the chapter
"Safety Precautions and Working
Techniques" before using your concrete
cutter. For further information you can
go to www.stihlusa.com
Contact your STIHL dealer or the STIHL
distributor for your area if you do not
understand any of the instructions in this
manual.
WARNING
Because a concrete cutter is a high-
speed cutting tool, some special safety
precautions must be observed to reduce
the risk of personal injury. Careless or
improper use may cause serious or even
fatal injury.
Guide to Using this Manual 2
Safety Precautions and Working
Techniques 3
Sample applications 15
Cutting Attachment 17
Mount guide bar and diamond
abrasive chain 17
Tension diamond abrasive chain 19
Check tension of diamond abrasive
chain 19
Fuel 20
Fueling 21
Starting / Stopping the Engine 22
Operating Instructions 25
Air Filter System 26
Remove air filter 26
Cleaning the Air Filter 27
Engine Management 27
Adjusting the Carburetor 27
Spark Arresting Screen in Muffler 29
Spark Plug 29
Rewind Starter 30
Storing the Machine 31
Taking Care of the Guide Bar 31
Checking and Replacing the Chain
Sprocket 32
Maintain and sharpen diamond
abrasive chain 33
Maintenance and Care 34
Main Parts 36
Specifications 38
Maintenance and Repairs 39
Disposal 39
STIHL Incorporated Federal
Emission Control Warranty
Statement 39
Trademarks 41

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Pictograms
The meanings of the pictograms
attached to or embossed on the
machine are explained in this manual.
Depending on the model concerned, the
following pictograms may be on your
machine.
Symbols in Text
Many operating and safety instructions
are supported by illustrations.
The individual steps or procedures
described in the manual may be marked
in different ways:
NA bullet marks a step or procedure.
A description of a step or procedure that
refers directly to an illustration may
contain item numbers that appear in the
illustration. Example:
NLoosen the screw (1).
NLever (2) ...
In addition to the operating instructions,
this manual may contain paragraphs
that require your special attention. Such
paragraphs are marked with the
symbols and signal words described
below:
DANGER
Indicates an imminent risk of severe or
fatal injury.
WARNING
Indicates a hazardous situation which, if
not avoided, could result in severe or
fatal injury.
NOTICE
Indicates a risk of property damage,
including damage to the machine or its
individual components.
Engineering Improvements
STIHL’s philosophy is to continually
improve all of its products. As a result,
engineering changes and improvements
are made from time to time. Therefore,
some changes, modifications and
improvements may not be covered in
this manual. If the operating
characteristics or the appearance of
your machine differs from those
described in this manual, please contact
your STIHL dealer or the STIHL
distributor for your area for assistance.
Guide to Using this Manual
Fuel tank for gasoline
and engine oil mixture at
50:1
Direction of chain rotation
Tension the chain
Press to operate decom-
pression valve
Water attachment, flow
control

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WARNING
Careless or improper use of any
concrete cutter may cause serious or
fatal injury.
Have your STIHL dealer show you how
to operate your concrete cutter. Observe
all applicable national, state and local
safety regulations, standards and
ordinances.
WARNING
Your concrete cutter is for professional
use only. Do not lend or rent your
concrete cutter without the instruction
manual. Be sure that anyone using it
understands the information contained
in this manual.
A first-time operator should obtain
practical instruction before using the
machine. Employers should establish a
training program for operators of
gasoline-powered, hand-held portable
concrete cutters to assure safe
operation of these machines.
WARNING
Your concrete cutter is suitable for
cutting concrete and certain other
materials. See the chapter entitled
"Cutting Attachment." For instance, it is
not suitable for cutting wood or wooden
objects. Misuse may result in personal
injury or property damage, including
damage to the machine.
WARNING
Minors should never be allowed to use a
concrete cutter. Bystanders, especially
children, and animals should not be
allowed in the area where a concrete
cutter is in use. Never let the concrete
cutter run unattended.
See the appropriate section of your
instruction manual for a description of
the controls and function of the parts of
your model concrete cutter.
Safe use of a concrete cutter involves
1. the operator
2. the power tool
3. the use of the power tool.
THE OPERATOR
Physical Condition
You must be in good physical condition
and mental health and not under the
influence of any substance (drugs,
alcohol, etc.) which might impair vision,
dexterity or judgment. Do not operate a
concrete cutter when you are fatigued.
WARNING
Be alert – if you get tired while operating
your concrete cutter, take a break;
tiredness may result in loss of control.
Working with any concrete cutter can be
strenuous. If you have any condition that
might be aggravated by strenuous work,
check with your doctor before operating
a concrete cutter.
WARNING
Prolonged use of concrete cutters (or
other machines) exposing the operator
to vibrations may produce whitefinger
disease (Raynaud's phenomenon) or
carpal tunnel syndrome. These
conditions reduce the hand's ability to
feel and regulate temperature, produce
numbness and burning sensations and
cause nerve and circulation damage and
tissue necrosis. All factors which
contribute to whitefinger disease are not
known, but cold weather, smoking and
diseases or physical conditions that
affect blood vessels and blood transport,
as well as high vibration levels and long
periods of exposure to vibration are
mentioned as factors in the development
of whitefinger disease. In order to
Safety Precautions and
Working Techniques
The use of this machine
may be hazardous.
Because a concrete cut-
ter is a high-speed, fast-
cutting power tool, spe-
cial safety precautions
must be observed to
reduce the risk of per-
sonal injury and fire.
It is important that you
read, fully understand
and observe the following
safety precautions and
warnings. Read the
instruction manual and
the safety precautions
periodically.

GS 461
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reduce the risk of whitefinger disease
and carpal tunnel syndrome, please
note the following:
–STIHL concrete cutters are
equipped with an anti-vibration
("AV") system designed to reduce
the transmission of vibrations
created by the machine to the
operator's hands. An AV system is
recommended for those persons
using concrete cutters on a regular
or sustained basis.
–Wear gloves and keep your hands
warm.
–Keep the AV system well
maintained. A concrete cutter with
loose components or with damaged
or worn AV elements will tend to
have higher vibration levels.
–Maintain a firm grip at all times, but
do not squeeze the handles with
constant, excessive pressure. Take
frequent breaks.
All the above-mentioned precautions do
not guarantee that you will not sustain
whitefinger disease or carpal tunnel
syndrome. Therefore, continual and
regular users should monitor closely the
condition of their hands and fingers. If
any of the above symptoms appear,
seek medical advice immediately.
WARNING
The ignition system of your unit
produces an electromagnetic field of a
very low intensity. This field may
interfere with some pacemakers. To
reduce the risk of serious or fatal injury,
persons with a pacemaker should
consult their physician and the
pacemaker manufacturer before
operating this tool.
Proper Clothing
WARNING
To reduce the risk of injury, the operator
should wear proper protective apparel.
Check the clothing manufacturer's
instructions. Keep clothing free of oil,
fuel, grease and other flammable
substances.
WARNING
Loose objects may be thrown toward the
operator by the cutting tool.
Wear an approved safety hard hat to
protect your head. Concrete cutter noise
may damage your hearing. Always wear
sound barriers (ear plugs or ear
mufflers) to help protect your hearing.
Regular users should have their hearing
checked regularly.
THE POWER TOOL
For illustrations and definitions of the
parts of the concrete cutter, see the
chapter "Main Parts."
Clothing must be sturdy
and snug-fitting, but allow
complete freedom of
movement. Avoid loose-
fitting jackets, scarfs,
neckties, jewelry, flared
or cuffed pants, uncon-
fined long hair or
anything that could
become caught on any
obstacles or moving parts
of the unit. Wear overalls
or long pants to protect
your legs. Do not wear
shorts.
Always wear heavy duty
work gloves (e.g. made of
leather or other wear
resistant material) when
handling the concrete
cutter. Heavy-duty, non-
slip gloves improve your
grip and help to protect
your hands.
Good footing is very
important. Wear sturdy
boots with nonslip soles.
Steel-toed safety boots
are recommended.
To reduce the risk of
injury to your eyes never
operate a concrete cutter
unless wearing goggles
or properly fitted safety
glasses with adequate
top and side protection
complying with
ANSI Z87 "+". Proper eye
protection is a must. If
there is a risk of injury to
your face, STIHL recom-
mends that you also wear
a face shield over your
goggles or protective
glasses.

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WARNING
Never modify a concrete cutter in any
way. Only STIHL branded parts and
cutting attachments expressly approved
by STIHL for use with the specific STIHL
concrete cutter model are
recommended. Although certain other
parts or attachments may be useable
with the STIHL powerhead, their use
may, in fact, be extremely dangerous.
If this tool is subjected to unusually high
loads for which it was not designed (e.g.
heavy impact or a fall), always check
that it is in good condition before
continuing work. Check in particular that
the fuel system is tight (no leaks) and
that the controls and safety devices are
working properly. Do not continue
operating this machine if it is damaged.
In case of doubt, have it checked by your
STIHL servicing dealer.
Diamond abrasive chain
The diamond abrasive chain, guide bar
and chain sprocket must match each
other and your concrete cutter.
If chains are used that are not STIHL
branded, over-aggressive cutting while
using the tip of the bar cannot be ruled
out, i.e., when exposed leading edges of
the diamond segments hammer against
the workpiece. This can damage the
chain and other components and may
lead to increased reactive forces
(kickback). See the section entitled
"Reactive Forces."
Only use diamond abrasive chain for the
specified materials, observe diamond
abrasive chain codes.
Always cut with water, see the chapter
entitled "Sample applications."
Before fitting used diamond abrasive
chains, check that they are not cracked,
chipped or have damaged or missing
segments; check also that there are no
signs of overheating (a bluish
discoloration), which could mean an
increased risk of breakage. Never use
diamond abrasive chains that have any
of these conditions. Consult your
servicing dealer.
THE USE OF THE POWER TOOL
Transporting the Power Tool
WARNING
To reduce the risk of injury from
diamond abrasive chain contact, never
carry or transport your power tool with
the diamond abrasive chain moving.
It may be carried only in a horizontal
position. Grip the front handle in a
manner that the machine is balanced
horizontally. Keep the hot muffler away
from your body and the cutting
attachment behind you.
WARNING
Always switch off the engine, and fit the
chain guard (scabbard) over the
diamond abrasive chain and guide bar
before transporting the power tool over
long distances. When transporting it in a
vehicle, properly secure it to prevent
turnover, fuel spillage and damage to
the unit.
Fuel
Your STIHL power tool uses an oil-
gasoline mixture for fuel (see the
chapter on "Fuel" of your instruction
manual.)
WARNING
WARNING
Dust may collect on the powerhead,
especially around the carburetor, and
may absorb gasoline resulting in a risk of
fire. Clean dust from the powerhead
regularly.
Fueling Instructions
WARNING
Fuel your power tool in well-ventilated
areas, outdoors. Always shut off the
engine and allow it to cool before
refueling. Gasoline vapor pressure may
build up inside the fuel tank depending
on the fuel used, the weather conditions
and the tank venting system.
Gasoline is an extremely
flammable fuel. If spilled
and ignited by a spark or
other ignition source, it
can cause fire and seri-
ous burn injury or
property damage. Use
extreme caution when
handling gasoline or fuel
mix. Do not smoke or
bring any fire or flame
near the fuel or the power
tool. Note that combusti-
ble fuel vapor may
escape from the fuel
system.

GS 461
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In order to reduce the risk of burns and
other personal injury from escaping gas
vapor and fumes, remove the fuel filler
cap on your power tool carefully so as to
allow any pressure build-up in the tank
to release slowly. Never remove the fuel
filler cap while the engine is running.
Select bare ground for fueling and move
at least 10 feet (3 m) from the fueling
spot before starting the engine. Wipe off
any spilled fuel before starting your
machine.
WARNING
WARNING
If fuel gets spilled on clothes, especially
trousers, it is very important to change
clothes immediately. Do not rely upon
evaporation. Flammable quantities of
fuel may remain on clothes after a spill
for longer than expected.
WARNING
Before use, make sure that the fuel cap
has been properly tightened and any
spilled fuel wiped away. An improperly
tightened fuel cap can loosen or come
off and spill quantities of fuel.
Bayonet Fuel Filler Cap
Never use a tool to open or close the
bayonet fuel filler cap, as this could
damage the cap and cause fuel to leak
out.
The bayonet fuel filler cap must be
closed with care after refuelling.
WARNING
Never attempt to force the cap open by
using a tool. It may damage the cap and
allow fuel to leak.
Before Starting
Take off the chain guard (scabbard) and
inspect the concrete cutter for proper
condition and operation. (See the
maintenance chart near the end of the
instruction manual.)
WARNING
Always check your power tool for proper
condition and operation before starting,
particularly the throttle trigger, throttle
trigger lockout, stop switch and cutting
tool. The throttle trigger must move
freely and always spring back to the idle
position. Never attempt to modify the
controls or safety devices.
WARNING
Check fuel system for leaks, especially
the visible parts, e.g., filler cap, hose
connections, manual fuel pump (only for
power tools equipped with a manual fuel
pump). Do not start the engine if there
are leaks or damage – risk of fire! Have
the machine repaired by a servicing
dealer before using it.
WARNING
Never operate your concrete cutter
without a front hand guard. This guard
helps protect your left hand.
WARNING
Never operate your power tool if it is
damaged, improperly adjusted or
maintained, or not completely or
securely assembled.
For proper assembly of the bar and
chain follow the procedure described in
the chapter "Mounting the Bar and
Diamond Abrasive Chain" of your
instruction manual. Diamond abrasive
chain, guide bar and sprocket must
match each other in gauge and pitch.
Before replacing any bar and chain, see
the chapter entitled "Specifications" in
the instruction manual.
WARNING
Always check the diamond abrasive
chain before use. Look for cracks and
make sure, that it is undamaged and in
good condition and that no pieces have
broken off.
Check for fuel leakage
while refueling and during
operation. If fuel leakage
is found, do not start or
run the engine until the
leak is fixed and any
spilled fuel has been
wiped away. Take care
not to get fuel on your
clothing. If this happens,
change your clothing
immediately.

GS 461
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WARNING
Proper tension of the chain is extremely
important. In order to avoid improper
setting, the tensioning procedure must
be followed as described in your
manual. Always make sure the
hexagonal nut(s) for the sprocket cover
is (are) tightened securely after
tensioning the chain in order to secure
the bar. Never start the concrete cutter
with the sprocket cover loose. Check
chain tension once more after having
tightened the nut(s) and thereafter at
regular intervals (whenever the concrete
cutter is shut off). If the chain becomes
loose while cutting, shut off the engine
and then tighten the chain. Never try to
adjust the chain while the engine is
running!
Keep the handles clean and dry; it is
particularly important to keep them free
of oil, fuel mix and grease in order for
you to maintain a firm grip and properly
control your power tool.
WARNING
Check that the spark plug boot is
securely mounted on the spark plug – a
loose boot may cause arcing that could
ignite combustible fumes and cause a
fire.
Starting
WARNING
To reduce the risk of fire and burn
injuries, start the engine at least 10 feet
(3 m) from the fueling spot, outdoors
only.
Start and operate your concrete cutter
without assistance. For specific starting
instructions, see the appropriate section
of the instruction manual.
Before starting, open the water shut-off
valve completely and ensure a supply of
water to the diamond abrasive chain –
do not allow diamond abrasive chain to
run dry. See chapter entitled "Sample
applications."
WARNING
Proper starting methods reduce the risk
of injury.
Do not drop start. This method is very
dangerous because you may lose
control of the concrete cutter.
There are two recommended methods
for starting your concrete cutter.
With the first recommended method, the
concrete cutter is started on the ground.
Place the concrete cutter on firm ground
or other solid surface in an open area.
Maintain good balance and secure
footing.
Grip the front handlebar of the concrete
cutter firmly with your left hand and
press down. Put the toe of your right foot
into the rear handle and press down.
With your right hand pull out the starter
grip slowly until you feel a definite
resistance and then give it a brisk,
strong pull.
The second recommended method for
starting your concrete cutter allows you
to start the concrete cutter without
placing it on the ground. Grip the front
handle of the concrete cutter firmly with
your left hand. Keep your left arm on the
front handle in a locked (straight)
position. Hold the rear handle of the
concrete cutter tightly between your legs
just above the knees. Maintain good
balance and secure footing. Pull the
2411BA022 KN
0001BA021 KN

GS 461
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starting grip slowly with your right hand
until you feel a definite resistance and
then give it a brisk, strong pull.
WARNING
Be sure that the guide bar and chain are
clear of you and all other obstructions
and objects, including the ground. When
the engine is started, the engine speed
with the starting throttle lock engaged
will be fast enough for the clutch to
engage the sprocket and turn the chain.
Never attempt to start the concrete
cutter when the guide bar is in a cut or
kerf.
As soon as the engine is running,
immediately blip the throttle trigger,
which will disengage the starting throttle
lock and allow the engine to settle down
to idle.
WARNING
When you pull the starter grip, do not
wrap the starter rope around your hand.
Do not let the grip snap back, but guide
the starter rope to rewind it properly.
Failure to follow this procedure may
result in injury to your hand or fingers
and may damage the starter
mechanism.
Important Adjustments
WARNING
To reduce the risk of personal injury
from loss of control and/or contact with
the running cutting tool, do not use your
unit with incorrect idle adjustment. At
correct idle speed, the cutting tool
should not move. For directions on how
to adjust idle speed, see the appropriate
section of your instruction manual.
If you cannot set the correct idle speed,
have your STIHL dealer check your
power tool and make proper
adjustments and repairs.
During Operation
Holding and Controlling the Power Tool
Always hold the unit firmly with both
hands on the handles while you are
working. Wrap your fingers and thumbs
around the handles. Your left hand
should grip the front handlebar.
Your right hand should grip the rear
handle. This also applies to left-handers.
With your hands in this position, you can
best oppose and absorb the push and
pull of your concrete cutter without
losing control (see section on reactive
forces).
WARNING
Your STIHL concrete cutter is designed
for hand-held use. Cutting with your
concrete cutter resting on the ground or
other surface can cause excessive wear
to the bracket designed to protect the
bottom of the tank housing. Loss of fuel
and personal injury from fire may result.
Replace damaged or badly worn
brackets immediately.
WARNING
To reduce the risk of serious or fatal
injury to the operator or bystanders from
loss of control, never use the concrete
cutter with one hand.
WARNING
To reduce the risk of cut injuries, keep
hands and feet away from the cutting
tool. Never touch a moving cutting tool
with your hand or any other part of your
body.
WARNING
Clear the area where you are working.
Avoid stumbling on obstacles and watch
out for holes or ditches. Be extremely
cautious when working on slopes or
uneven ground. Take extreme care in
wet and freezing weather (rain, snow,
ice.) Keep in mind that water from the
water attachment may affect footing.
WARNING
To reduce the risk of injury from loss of
control, never work on a ladder or any
other insecure support. Never hold the
machine above shoulder height. Do not
overreach.
2411BA046 KN

GS 461
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9
Position the concrete cutter in such a
way that your body is clear of the cutting
attachment whenever the engine is
running. Stand to the left of cut while
cutting.
Working Conditions
Operate and start your power tool only
outdoors in a well ventilated area.
Operate it under good visibility and
daylight conditions only. Work carefully.
WARNING
Your concrete cutter is a one-person
machine. Do not allow other persons in
the general work area, even when
starting. Stop the engine immediately if
you are approached.
Use extreme caution when cutting
openings, recesses, etc., someone
could be standing behind them – look
beforehand.
WARNING
Even though bystanders should be kept
away from the running concrete cutter,
never work alone. Keep within calling
distance of others in case help is
needed. Wearing of hearing protection
reduces sound perception. Be alert not
to miss voice signals from co-workers.
WARNING
WARNING
Use of this product to cut certain
materials can generate dust and fumes
containing chemicals known to cause
serious or fatal injury or illness, such as
respiratory disease, cancer, birth
defects or other reproductive harm. If
you are unfamiliar with the risks
associated with the particular material
being cut, review the material safety
data sheet and/or consult your
employer, the material
manufacturer/supplier, governmental
agencies such as OSHA and NIOSH
and other sources on hazardous
materials. California and some other
authorities, for instance, have published
lists of substances known to cause
cancer, reproductive toxicity, etc.
Control dust and fumes at the source
where possible. In this regard use good
work practices and follow the
recommendations of the
manufacturer/supplier, OSHA/NIOSH,
and occupational and trade
associations.
Even if wet cutting, an operator who is
actively cutting for more than two hours
in one day should wear at least a
NIOSH-approved disposable respirator.
Consult and follow any federal, state or
local laws or regulations.
WARNING
Cutting masonry, concrete and other
materials with silica in their composition
may give off dust containing crystalline
silica. Silica is a basic component of
sand, quartz, brick clay, granite and
numerous other minerals and rocks.
Repeated and/or substantial inhalation
of airborne crystalline silica can cause
serious or fatal respiratory diseases,
including silicosis. In addition, California
and some other authorities have listed
respirable crystalline silica as a
substance known to cause cancer.
When cutting such materials, always
follow the respiratory precautions
mentioned above.
WARNING
Breathing asbestos dust is dangerous
and can cause severe or fatal injury,
respiratory illness or cancer. The use
and disposal of asbestos-containing
products have been strictly regulated by
2411BA003 KN
As soon as the engine is
running, this product gen-
erates toxic exhaust
fumes containing chemi-
cals, such as unburned
hydrocarbons (including
benzene) and carbon
monoxide, that are
known to cause respira-
tory problems, cancer,
birth defects, or other
reproductive harm. Some
of the gases (e.g. carbon
monoxide) may be color-
less and odorless. To
reduce the risk of serious
or fatal injury/illness from
inhaling toxic fumes,
never run the machine
indoors or in poorly venti-
lated locations. Ensure
proper ventilation when
working in trenches or
other confined areas.

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10
OSHA and the Environmental Protection
Agency. Do not use your concrete cutter
to cut or disturb asbestos, asbestos-
containing products, or products such as
pipes which are wrapped or covered
with asbestos insulation. If you have any
reason to believe that you might be
cutting asbestos, immediately contact
your employer or a local OSHA
representative.
WARNING
To reduce the risk of injury from fire, do
not cut into any pipe, drum or other
container without first ensuring that it
does not contain a volatile or flammable
substance.
WARNING
When cutting into existing walls, floors or
similar structures, be alert for hidden
hazards such as electrical cables, water
and gas pipes and flammable
substances. Make sure that power,
water and gas have been shut off and
pipes drained before starting to cut.
Always check the other side before
cutting.
Operating Instructions
Ensure sufficient water supply to
diamond abrasive chain – do not allow
diamond abrasive chain to run dry.
Always completely open water shut-off
valve. Always wet cut – regardless of the
material to be cut. See chapter entitled
"Sample applications."
WARNING
Never operate near live electric wires.
To reduce the risk of electrocution to you
or bystanders, do not allow water or
sludge to contact live electric wires.
WARNING
Always check the diamond abrasive
chain before use and after
unintentionally striking any object;
frequently check it during use when it is
stopped. Look for cracks and make sure
that it is undamaged and in good
condition and that no pieces have
broken off.
WARNING
Check chain tension at regular intervals
during use (whenever the concrete
cutter is shut off). If the chain becomes
loose while cutting, shut off the engine
and then tighten the chain. Never try to
adjust the chain while the engine is
running! See chapter "Tension diamond
abrasive chain."
WARNING
Never operate the concrete cutter with
the starting-throttle lock engaged as this
does not permit proper control of the
speed of the unit and may lead to
serious injury.
WARNING
In the event of an emergency, switch off
the engine immediately – move the slide
control / stop switch to 0 or STOP.
WARNING
Always stop the engine and be sure the
chain has stopped rotating before
putting a concrete cutter down.
WARNING
The diamond abrasive chain continues
to move for a short period after the
throttle trigger is released (flywheel
effect).
Accelerating the engine while the
diamond abrasive chain is blocked
increases the load and will cause the
clutch to slip continuously. This may
occur if the throttle is depressed for
more than a few seconds when the
chain is pinched in the cut. It can result
in overheating and damage to important
components (e.g. clutch, polymer
housing components) – which can then
increase the risk of injury, e.g., from the
diamond abrasive chain moving while
the engine is idling.
WARNING
It is essential to determine the exact
direction of the cut before applying the
diamond abrasive chain to the work.
Diamond abrasive chains are
constructed for radial pressure only.
Lateral pressure must be avoided. Hold
the concrete cutter steady. To reduce
the risk of serious or fatal injury, do not
change the direction of the cut during the
cut as this may produce a high torsional
load on the diamond abrasive chain and
may cause it to bind, break or shatter.
If cutting performance begins to
deteriorate, check the sharpness of the
diamond abrasive chain, resharpen as

GS 461
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11
needed. To do this, briefly cut through
abrasive material, e. g., sandstone,
aerated concrete or asphalt.
WARNING
Do not use diamond abrasive chains for
rough grinding. Large bending stresses
occur during such work, which may
cause diamond abrasive chains to
shatter or break and result in serious or
fatal injury.
WARNING
To reduce the risk of injury from
shattered diamond abrasive chains:
1. Do not cut any material for which the
diamond abrasive chain is not
authorized.
2. Do not grind with the side of the
diamond abrasive chain.
3. Do not twist, thrust, knock or drop
the machine. This can cause
damage to the diamond abrasive
chain.
Do not use excessive force to push the
diamond abrasive chain into the work.
Do not cock, jam or wedge the diamond
abrasive chain in the cut.
WARNING
Inspect antivibration elements
periodically. Replace damaged, broken
or excessively worn antivibration
elements immediately, since they may
result in loss of control of the concrete
cutter. A "sponginess" in the feel of the
concrete cutter, increased vibration or
increased "bottoming out" during normal
operation may indicate damage,
breakage or excessive wear.
Antivibration elements should always be
replaced in sets. If you have any
questions as to whether the antivibration
elements should be replaced, consult
your STIHL servicing dealer.
WARNING
Your concrete cutter is not designed for
prying or shoveling objects. Such use
could damage the cutting attachment or
AV system.
WARNING
Never modify your muffler. Any
modification could cause an increase in
heat radiation, sparks or sound level,
thereby increasing the risk of fire, burn
injury or hearing loss. You may also
permanently damage the engine. Have
your muffler serviced and repaired by
your STIHL servicing dealer only.
WARNING
The muffler and other parts of the engine
(e.g. fins of the cylinder, spark plug)
become hot during operation and remain
hot for a while after stopping the engine.
To reduce risk of burns, do not touch the
muffler and other parts while they are
hot. Keep the area around the muffler
clean. Remove excess debris. Let the
machine cool down sitting on concrete,
metal, bare ground or solid wood away
from any combustible substances.
WARNING
An improperly mounted or damaged
cylinder housing or a
damaged/deformed muffler shell may
interfere with the cooling process of the
muffler. To reduce the risk of fire or burn
injury, do not continue work with a
damaged or improperly mounted
cylinder housing or a
damaged/deformed muffler shell.
Your muffler is furnished with a spark
arresting screen designed to reduce the
risk of fire from the emission of hot
particles. Never operate your unit with a
missing or damaged spark arresting
screen. If your gas/oil mix ratio is correct
(i.e., not too rich), this screen will
normally stay clean as a result of the
heat from the muffler and need no
service or maintenance. If you
experience loss of performance and you
suspect a clogged screen, have your
muffler maintained by a STIHL servicing
dealer. Some state or federal laws or
regulations may require a properly
maintained spark arrestor for certain
uses. See the "Maintenance, Repair and
Storing" section of these Safety
Precautions.
Reactive Forces
WARNING
Reactive forces may occur any time the
chain is rotating. Reactive forces can
cause serious personal injury. The
powerful force used to cut through a
workpiece can be reversed and work
against the operator. If the rotating chain
is suddenly stopped by contact with any
solid object or by a pinch or binding,
reactive forces can occur instantly and
may result in the operator losing control
of the concrete cutter, which, in turn,
may result in serious or fatal injury.

GS 461
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12
An understanding of the causes of these
reactive forces may help you avoid loss
of control. Reactive forces are exerted in
a direction opposite to the direction in
which the chain is moving at the point of
contact or of pinching / binding. If the
chain is slowed solely by frictional
contact with a solid object, such as the
workpiece, the resulting reactive forces
are normally moderate and readily
controllable by an operator who is
holding the machine properly. If,
however, the chain is abruptly slowed or
stopped by a pinch or severe bind, the
reactive forces may be substantially
greater. The greater the force
generated, the more difficult it will be for
the operator to control the concrete
cutter. Loss of control can result in
severe personal injury.
The most common reactive forces are:
–rotational reactive forces,
–pull-in,
–pushback.
A = Rotational reactive forces
WARNING
Rotational reactive forces may occur
when the moving chain near the upper
quadrant of the bar nose is pinched. This
may fling the bar up and back in the
plane of he bar. In some circumstances,
the bar may move towards the operator,
who may suffer severe or fatal injury.
These reactive forces may occur, for
example, when plunge-cutting. See
section on plunge-cutting.
B = Pull-in
Pull-in may occur when the chain on the
bottom of the bar is suddenly stopped
when it is pinched, caught or encounters
a foreign object in the workpiece. The
reaction of the chain pulls the concrete
cutter forward and may cause the
operator to lose control.
Pull-in occurs when the chain is not
rotating at full speed before it contacts
the workpiece.
To avoid Pull-in
1. Always start a cut with the chain
rotating at full speed
2. The risk of pull-in may also be
reduced by using wedges to keep
the kerf or cut open.
C = Pushback
Pushback may occur when the chain on
the top of the bar is suddenly stopped
when it is pinched, caught or encounters
a foreign object in the workpiece. The
reaction of the chain may drive the
concrete cutter rapidly straight back
toward the operator and may cause loss
of concrete cutter control. Pushback
frequently may occur when the top of the
bar is used for cutting.
To avoid Pushback
1. Be alert to forces or situations that
may cause material to pinch the
chain on top of the bar.
2. Do not twist the concrete cutter
when withdrawing the bar from a
underbuck cut because the chain
can pinch.
Pinching occurs when the piece being
cut closes on the chain. A severe
binding may also occur if the chain is
substantially sideloaded in the kerf.
Such situations can and should always
be avoided. Pinching of the chain can be
prevented by proper support of the
workpiece. (See below.) Severe binding
of the chain can be prevented by proper
cutting techniques, e.g., not sideloading
the chain, and by the use of properly
designed, manufactured and maintained
chains.
2411BA051 KN
A
2411BA052 KN
B
2411BA053 KN
C

GS 461
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13
Be alert to potential movement of the
workpiece or anything else that could
cause the cut to close and pinch the
chain. In order to reduce the risk of
pinching, support the workpiece in such
a way that the cut remains open during
the cutting process and when the cut is
finished (see illustration.) Never make a
cut that results in a binding of the chain.
WARNING
Be particularly alert when cutting a
workpiece such as a pipe with a belled
end or a pipe in a trench that, if not
properly supported, can sag upon
completion of the cut, creating a pinch
not where you are actually cutting but,
rather, at or near the top of the
workpiece.
WARNING
Always use wet-cutting, since the water
can act as a lubricant in a pinch situation
and thus reduce the likelihood of
reactive forces occurring and the energy
of any such forces that do occur, making
it easier to maintain control of the
machine.
WARNING
To reduce the risk of injury from loss of
control from reactive forces:
1. Hold the concrete cutter machine
firmly with both hands.
2. Maintain good balance and footing
at all times. Never cut while
standing on a ladder or other
insecure support.
3. Position the concrete cutter in such
a way that your body is clear of the
cutting attachment. Avoid standing
in direct line with the chain (See
illustration.) Never bend over the
cutting attachment.
4. Do not cut above shoulder height.
5. Only STIHL branded parts and
cutting attachments expressly
approved by STIHL for use with the
specific STIHL concrete cutter
model are recommended. Although
certain other parts or attachments
may be useable with the STIHL
powerhead, their use may, in fact,
be extremely dangerous.
6. Do not cut wood or any other
material for which the diamond
abrasive chain is not authorized.
7. Begin cutting and continue at full
throttle.
8. Do not overreach.
9. Never sideload a chain in the kerf.
10. Use your concrete cutter for cutting
only. It is not designed for prying or
shoveling away any objects.
11. Be especially alert for reactive
forces, when cutting with the front
and upper quadrant of the chain.
12. Be alert to shifting of the workpiece
or anything that could cause the cut
to close and pinch the chain,
especially in the upper quadrant.
Support the workpiece in such a
way that the cut remains open.
Never make a cut that results in a
binding of the chain.
13. Always use wet-cutting. In a pinch
situation the water can act as a
lubricant and reduce the energy of
reactive forces.
14. Release any pressure on the
concrete cutter as you reach the
end of the cut. Too much pressure
may cause the operator to lose
control of the concrete cutter when
the diamond abrasive chain
completes the cut. The chain may
contact the operator or strike some
foreign object and break.
15. Use extreme caution when
reentering a cut and do not turn the
chain at an angle or push the chain
into the cut as this may result in a
binding of the chain.
MAINTENANCE, REPAIR AND
STORING
Maintenance, replacement, or repair of
the emission control devices and
systems may be performed by any
nonroad engine repair establishment or
individual. However, if you make a
002BA146 KN
2411BA003 KN

GS 461
English
14
warranty claim for a component that has
not been serviced or maintained
properly or if nonapproved replacement
parts were used, STIHL may deny
warranty coverage.
Never operate a concrete cutter that is
damaged, improperly adjusted or not
completely or securely assembled.
Follow the maintenance and repair
instructions in the appropriate sections
of your instruction manual.
WARNING
Use only STIHL replacement parts for
maintenance and repair. Use of parts
manufactured by others may cause
serious or fatal injury.
WARNING
Always stop the engine and make sure
that the cutting tool is stopped before
doing any maintenance or repair work or
cleaning the power tool.
WARNING
Do not attempt any maintenance or
repair work not described in your
instruction manual. Have such work
performed only at your STIHL servicing
dealer.
Clean off grinding dust after finishing
work. Tighten all nuts, bolts and screws
except the carburetor adjustment
screws after each use.
Do not clean your machine with a
pressure washer. The solid jet of water
may damage parts of the machine.
WARNING
Never test the ignition system with spark
plug boot removed from spark plug or
with an unseated spark plug, since
uncontained sparking may cause a fire.
WARNING
To reduce the risk of fire and burn injury,
use only spark plugs authorized by
STIHL. Always press spark plug boot
snugly onto spark plug terminal of the
proper size. (Note: If terminal has a
detachable SAE adapter nut, it must be
attached.) A loose connection between
spark plug terminal and ignition wire
connector in the boot may create arcing
that could ignite combustible fumes and
cause a fire. Keep spark plug clean, and
make sure ignition lead is in good
condition.
WARNING
Do not operate your power tool if the
muffler is damaged, missing or modified.
An improperly maintained muffler will
increase the risk of fire and hearing loss.
Never touch a hot muffler or spill fuel or
other flammable liquid over it. Burn
injuries or fire will result. If your muffler
was equipped with a spark-arresting
screen to reduce the risk of fire (e. g. in
the USA, Canada and Australia), never
operate your power tool if the screen is
missing or damaged.
In California, it is a violation of § 4442 or
§ 4443 of the Public Resources Code to
use or operate gasoline-powered tools
on forest-covered, brush-covered or
grass-covered land unless the engine’s
exhaust system is equipped with a
complying spark arrester that is
maintained in effective working order.
The owner/operator of this product is
responsible for properly maintaining the
spark arrester. Other states or
governmental entities/agencies, such as
the U.S. Forest Service, may have
similar requirements. Contact your local
fire agency or forest service for the laws
or regulations relating to fire protection
requirements.
For any maintenance please refer to the
maintenance chart and to the warranty
statement near the end of the instruction
manual.
Keep the chain, bar and sprocket clean;
replace worn sprockets or chains. Keep
the chain at proper tension.
Store concrete cutter in a high or locked
place, away from children.
Empty the fuel tank before storing for
longer than a few days. Store fuel only in
correctly labeled and approved
containers. Avoid direct skin contact and
do not inhale the gas vapors.

GS 461
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15
The water introduced is used to cool the
diamond abrasive chain and rinse
material from the bar groove and the rest
of the cutting attachment, and for
binding dust.
If the water pressure or water volume is
too low, this leads to significantly
increased wear and irreparable damage
to the cutting attachment – risk of chain
breakage and/or increased dust
exposure!
Objects to be cut
–Must be fully supported
–Must be secured so they cannot roll
or slip off
–Must be prevented from vibrating
Severed workpiece parts
With openings, recesses, etc., the
sequence of the cuts is important.
Always make the last cut so that the
diamond abrasive chain does not
become jammed and so that the
operator is not endangered by the
severed or separated part.
If necessary, use wedges and if
necessary, leave small ridges that hold
the part that is to be separated in
position. Break these ridges later.
Before finally separating the part,
determine:
–support or secure properly
–how heavy the part is
–how it can move after separation
–whether it is under tension
When breaking out the part, do not
endanger bystanders.
Plunge-cutting
Begin cutting with the concrete cutter at
full throttle.
1. Apply the lower portion of the guide
bar nose.
2. Swing slowly into the plunge-cutting
position.
3. Make the plunge cut very carefully.
WARNING
When making the plunge cut into
existing, narrower joints, proceed with
extreme care. The sides of the narrower
cut could pinch the chain in the upper
quadrant of the bar tip and lead to
reactive forces. See the section entitled
"Reactive Forces."
Cut in several passes
NMark cutting line (A).
NWork along the cutting line. When
making corrections, do not tilt the
diamond abrasive chain, always
withdraw the bar and reposition it.
Sample applications
Use diamond abrasive
chain only with water.
Connect concrete cutter
to water supply network
(min. 22 PSI (1.5 bar)).
3.
2411BA004 KN
1.
2.
A
2411BA005 KN
2411BA006 KN

GS 461
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16
Cutting round and hollow bodies
NSecure pipes, round bodies, etc.
against rolling away.
NMark a cutting line - when
determining the cutting line, avoid
reinforcement, especially in the
direction of the severing cut.
NMake the plunge cut very carefully.
NFeed with bar completely through
the wall of the workpiece along the
cutting line – for small corrections of
direction, do not tilt the diamond
abrasive chain, but always position
it anew instead – if necessary, use
wedges and if necessary, leave
small ridges that hold the part that is
to be separated in position. Break
these ridges later.
Shaping pipe
NSecure pipes, round bodies, etc.
against rolling away.
NMark a cutting line - when
determining the cutting line, avoid
reinforcement, especially in the
direction of the severing cut.
WARNING
Manual cutting along this line requires
particular caution and precision.
NCut into pipes, round bodies, etc. in
the area at the ends of the cutting
line a short distance, so that the
material does not break away.
NMake the plunge cut very carefully
at the apex and cut outward on both
sides - feed with full cutting depth
along the cutting line – for small
corrections of direction, do not tilt
the diamond abrasive chain, but
always position it anew instead – if
necessary, use wedges and if
necessary, leave small ridges that
hold the part that is to be separated
in position. Break these ridges later.
2411BA007 KN
2411BA008 KN

GS 461
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17
Diamond abrasive chain, guide bar and
chain sprocket make up the cutting
attachment.
The cutting attachment that is supplied
has been optimized for the concrete
cutter.
–The pitch (t) of the diamond
abrasive chain (1), chain sprocket
and sprocket nose of the Rollomatic
guide bar must match
–The drive link gauge (2) of the
diamond abrasive chain (1) must be
matched to the groove width of the
guide bar (3)
When pairing components that are not
compatible with each other, the cutting
attachment may become damaged
beyond repair after only a short period of
operation.
Diamond abrasive chain
The correct use of the STIHL diamond
abrasive chain ensures economical use
and avoids accelerated wear.
The STIHL diamond abrasive chain is
suitable for cutting the following
materials:
–Concrete
–Reinforced concrete (with rebar up
to 1/2 inch)
–Cinder blocks
–Masonry, including bricks
–Asphalt and soft stone, such as
sandstone
–Hard stone*, such as granite*
–ductile cast iron pipes*
*) Reduction in cutting performance and
service life are possible
Do not cut any other materials – risk of
property damage, including damage to
the concrete cutter or its chain, and
possibly personal injury.
Chain scabbard
The GS product includes a chain
scabbard that is suitable for covering the
bar and chain.
Removing the chain sprocket cover
NUnscrew nuts (1) from the studs –
nuts are fastened to the chain
sprocket cover so that they are
secured against loss
NRemove chain sprocket cover (2)
NTurn the screw (3) to the left until
the tensioner slide (4) butts against
the left end of the housing slot
Cutting Attachment
2411BA009 KN
1
2
3
a
t = a : 2
Mount guide bar and
diamond abrasive chain
11
2411BA011 KN
2
4
2411BA012 KN
3

GS 461
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18
Fit diamond abrasive chain
NFit the diamond abrasive chain
starting at the nose of the guide bar
NPosition the guide bar over the
bolts (1) – align drive links so that
the position lines up with the symbol
(arrow)
WARNING
If the drive links are not directionally
aligned one behind the other correctly,
the diamond abrasive chain and chain
sprocket will be damaged beyond repair.
NPosition the right locating hole (2)
over the peg of the tensioner slide –
simultaneously place the diamond
abrasive chain over the sprocket
wheel (3)
NTurn screw (4) to the right until there
is very little diamond abrasive chain
sag on the underside of the bar and
the lugs of the drive links engage in
the bar groove
NRefit the chain sprocket cover – and
then screw on the nut by hand until
it is fingertight
NGo to chapter "Tensioning the
diamond abrasive chain"
Moving the guide bar
Only move the guide bar if the diamond
abrasive chain cannot be tensioned
properly.
NRemoving the chain sprocket cover
NRemove guide bar with diamond
abrasive chain
NFit the diamond abrasive chain
starting at the nose of the guide bar
NPosition the guide bar over the
bolts (1) – align drive links so that
the position lines up with the symbol
(arrow)
WARNING
If the drive links are not directionally
aligned one behind the other correctly,
the diamond abrasive chain and chain
sprocket will be damaged beyond repair.
NPosition the left locating hole (5)
over the peg of the tensioner slide –
simultaneously place the diamond
abrasive chain over the sprocket
wheel (3)
NTurn screw (4) to the right until there
is very little diamond abrasive chain
sag on the underside of the bar and
the lugs of the drive links engage in
the bar groove
NRefit the chain sprocket cover – and
then screw on the nuts by hand until
they are fingertight
NGo to chapter "Tensioning the
diamond abrasive chain"
2411BA013 KN
4
11
2411BA0014 KN
4
11
2411BA049 KN