Stihl GS 461 User manual

STIHL GS 461
Instruction Manual2 - 28

Contents
1 Guide to Using this Manual.........................2
2 Safety Precautions and Working Techni‐
ques............................................................ 3
3 Sample Applications................................... 8
4 Cutting Attachment................................... 10
5 Mount Guide Bar and Diamond Abrasive
Chain.........................................................10
6 Tension Diamond Abrasive Chain............ 12
7 Check Tension of Diamond Abrasive Chain
.................................................................. 12
8 Fuel........................................................... 12
9 Fueling...................................................... 13
10 Starting / Stopping the Engine.................. 15
11 Operating Instructions...............................18
12 Air Filter System........................................19
13 Remove Air Filter...................................... 19
14 Cleaning the Air Filter............................... 19
15 Adjusting the Carburetor........................... 19
16 Spark Plug................................................ 20
17 Storing the Machine.................................. 21
18 Taking Care of the Guide Bar................... 22
19 Checking and Replacing the Chain
Sprocket....................................................22
20 Maintain and Sharpen Diamond Abrasive
Chain.........................................................23
21 Maintenance and Care..............................23
22 Minimize Wear and Avoid Damage...........25
23 Main Parts.................................................26
24 Specifications............................................26
25 Maintenance and Repairs......................... 27
26 Disposal.................................................... 27
27 EC Declaration of Conformity................... 27
28 UKCA Declaration of Conformity.............. 28
Dear Customer,
Thank you for choosing a quality engineered
STIHL product.
It has been built using modern production techni‐
ques and comprehensive quality assurance.
Every effort has been made to ensure your satis‐
faction and trouble-free use of the product.
Please contact your dealer or our sales company
if you have any queries concerning this product.
Your
Dr. Nikolas Stihl
1 Guide to Using this Manual
1.1 Image Symbols
The meanings of the image symbols on the tool
are explained in this manual.
Depending on the model concerned, the follow‐
ing image symbols may be on your machine.
Fuel tank; fuel mixture of gasoline
and engine oil
Direction of chain rotation
Tension diamond abrasive chain
Operate decompression valve
Water connection, shut-off cock
1.2 Symbols in text
WARNING
Warning where there is a risk of an accident or
personal injury or serious damage to property.
NOTICE
Caution where there is a risk of damaging the
machine or its individual components.
1.3 Engineering improvements
STIHL's philosophy is to continually improve all
of its products. For this reason we may modify
the design, engineering and appearance of our
products periodically.
Therefore, some changes, modifications and
improvements may not be covered in this man‐
ual.
English
2 0458-761-0121-B
© ANDREAS STIHL AG & Co. KG 2021
0458-761-0121-B. VA0.H21.
Printed on chlorine-free paper Printing inks contain vegetable oils, paper can be recycled.
Original Instruction Manual 0000006258_020_GB

2 Safety Precautions and
Working Techniques
Because the chain of a concrete cut‐
ter runs at very high speeds, special
safety precautions must be observed
to reduce the risk of personal injury.
It is important you read and under‐
stand the User Manual before com‐
missioning and keep it in a safe place
for future reference. Non-compliance
with the User Manual may cause seri‐
ous or even fatal injury.
Observe all applicable local safety regulations,
e.g. by trade organizations, social insurance
institutions, labor safety authorities etc.
If you have never used a power tool before:
Have your dealer or other experienced user
show you how to operate your machine – or
attend a special course to learn how to operate
it.
Minors should never be allowed to use the
machine – except for apprentices over the age of
16 when working under supervision.
Children, animals and bystanders must remain at
a distance.
When not using the machine, it must be laid
down in such a way that it does not endanger
anyone. Ensure that the machine cannot be
used without authorization.
The user is responsible for accidents or risks
involving third parties or their property.
Do not lend or rent your power tool without the
User Manual. Be sure that anyone using it under‐
stands the information contained in this manual.
The use of machines that emit noise may be limi‐
ted to certain hours of the day as specified by
national and/or regional or local regulations.
Anyone operating the machine must be well res‐
ted, in good physical health and in good mental
condition.
If you have any condition that might be aggrava‐
ted by strenuous work, check with your doctor
before operating a machine.
If you have a pacemaker: The ignition system of
your machine produces an electromagnetic field
of very low intensity. This field may interfere with
some pacemakers. STIHL recommends that per‐
sons with pacemakers consult their physician
and the pacemaker manufacturer to reduce any
health risk.
Anyone who has consumed alcohol or drugs or
medicines affecting their ability to react must not
operate a power tool.
To reduce the risk of accidents or injury, put off
the work in poor weather conditions (rain, snow,
ice, wind).
The machine may only be used for cutting.
The machine must not be used for any other pur‐
poses – risk of accidents!
It is not suitable for cutting wood or wooden
objects.
Asbestos dust is extremely toxic - the machine
must therefore never be used to cut asbestos!
Only use tools, guide bars, diamond abrasive
chains or accessories which have been
approved by STIHL for this machine or which are
technically equivalent. If you have any questions
in this respect, consult your dealer. Use only high
quality parts and accessories. in order to avoid
the risk of accidents and damage to the machine.
STIHL recommends the use of genuine STIHL
guide bars, diamond abrasive chains, chain
sprockets and accessories. They are specifically
designed to match the product and meet your
performance requirements.
Never attempt to modify your power tool in any
way since this may increase the risk of personal
injury. STIHL excludes all liability for personal
injury and damage to property caused while
using unauthorized attachments.
Do not use a high-pressure washer to clean the
power tool. The solid jet of water may damage
parts of the unit.
2.1 Clothing and equipment
Wear proper protective clothing and equipment.
Clothing must be sturdy but allow
complete freedom of movement.
Wear close-fitting clothes such as a
boiler suit, not a loose jacket.
Do not wear garments that could get caught in
moving parts of the machine – such as scarves,
neckties, jewelry. Tie up and confine long hair
above your shoulders.
Wear steel-toed safety boots with
non-slip soles.
2 Safety Precautions and Working Techniques English
0458-761-0121-B 3

WARNING
To reduce the risk of eye injuries,
wear close-fitting safety glasses in
accordance with European Standard
EN 166. Make sure the safety
glasses are a snug fit.
Wear face protection and make sure it is a good
fit. Face protection alone is not sufficient to pro‐
tect the eyes.
Wear "personal" sound protection, e.g. ear
defenders.
Wear a safety hard hat where there is a danger
of head injuries from falling objects.
Dust (e. g., crystalline material from the object
being cut), fumes and smoke may be produced
while cutting - health hazard!
Always wear a dust mask if dust is generated.
If fumes or smoke are anticipated (e. g., when
cutting composite materials), wear respiratory
protection.
Wear sturdy protective gloves made
of a resistant material (e. g. leather).
STIHL can supply a comprehensive range of per‐
sonal protective equipment.
2.2 Transporting the machine
Always stop the engine and attach the chain
scabbard.
Carry the machine only by the handlebar – guide
bar towards the rear – with the hot muffler facing
away from the body.
To avoid serious burn injuries, avoid touching hot
parts of the machine, especially the surface of
the muffler.
By vehicle: When transporting in a vehicle, prop‐
erly secure your machine to prevent turnover,
damage and fuel spillage.
2.3 Refueling
Gasoline is highly flammable – keep
away from fire or flame – do not spill
any fuel – no smoking.
Always shut off the engine before refueling.
Do not fuel a hot engine – fuel may spill and
cause a fire!
Open the fuel cap carefully to allow any pressure
build-up in the tank to release slowly and avoid
fuel spillage.
Only refuel the machine in a well ventilated
place. If fuel has been spilled, immediately clean
the machine – do not allow your clothes to be
splashed with fuel. If that happens, change your
clothes at once.
Dust may collect on the engine unit, particularly
around the carburetor. If dust gets mixed with
fuel – risk of fire. For this reason, ensure that the
dust is always removed.
Check for fuel leakage! Never start
the engine if fuel has been spilled or
is leaking – Fatal burns may result!
2.3.1 Bayonet-type fuel cap
Never use a tool to open or close the bayonet-
type fuel cap. This could damage the cap and
cause fuel to leak out.
Close the bayonet-type fuel cap carefully after
refueling.
2.4 Diamond abrasive chain
The diamond abrasive chain, guide bar and
chain sprocket must match each other and your
concrete cutter.
Use only approved diamond abrasive chains. If
unauthorized chains are used, aggressive cutting
behavior cannot be ruled out. This may lead to
uncontrolled and exceedingly dangerous reac‐
tion forces (kickback) in the machine – risk of
fatal injuries!
Only use diamond abrasive chain for the speci‐
fied materials, observe diamond abrasive chain
codes.
Always cut with water.
Before fitting used diamond abrasive chains,
check that they are not cracked, chipped, check
English 2 Safety Precautions and Working Techniques
4 0458-761-0121-B

also that there are no damaged or missing seg‐
ments, signs of overheating (discoloration).
Never use diamond abrasive chains that are
cracked or have chipped segments. contact your
servicing dealer.
2.5 Before starting
Check that concrete cutter is properly assembled
and in good condition – refer to appropriate
chapters in the User Manual:
–Check the fuel system for leaks, especially the
visible parts, e. g., fuel cap, hose connections,
manual fuel pump (only in machines with a
manual fuel pump). In case of leakage and
damage, do not start the engine – risk of fire!
Have the machine serviced by a dealer before
commissioning
–Check operation of front hand guard
–Check the chain sprocket
–Sprocket nose moves easily
–Correctly mounted guide bar
–The diamond abrasive chain must be suitable
for the material to be cut. It must be in good
condition and fitted correctly (direction of run‐
ning)
–Correctly tensioned diamond abrasive chain
–Smooth action of throttle trigger and throttle
trigger lockout – throttle trigger must return
automatically to idle position
–Master control lever can be moved to STOP or
0
–Check that the spark plug boot is secure – a
loose boot may cause arcing that could ignite
combustible fumes and cause a fire!
–Never attempt to modify the controls or safety
devices
–Keep the handles dry and clean, free from oil
and dirt – important for safe control of the con‐
crete cutter
The concrete cutter should only be used if it is in
full working order – risk of accident!
2.6 Starting the engine
Start the engine at least 3 meters from the fuel‐
ing spot, outdoors only.
The machine may only be used on level ground.
Ensure a firm and secure footing and hold the
machine firmly. The diamond abrasive chain
must not touch any objects or the ground and
must not be in the cut, because it may begin to
rotate when the machine is started.
The machine is operated by a single person only
– do not allow any person to stay within the work‐
ing area – nor with starting.
Do not drop-start the power tool – start the
engine as described in the user manual.
Before starting, open the shut-off valve com‐
pletely and ensure a supply of water to the dia‐
mond abrasive chain – do not allow diamond
abrasive chain to run dry.
2.7 Holding and guiding the
machine
2411BA046 KN
Always hold the machine firmly with both hands:
Right hand on the rear handle – even if you are
left-handed. To ensure safe control, wrap your
fingers tightly around both handles.
The object to be cut off has to be firmly suppor‐
ted. Always guide the machine towards the work‐
piece – never the other way round.
2.8 While working
Make sure you always have good balance and
secure footing.
In the event of impending danger or in an emer‐
gency, switch off the engine immediately by mov‐
ing the master control lever to STOPor0.
Your power tool is designed to be operated by
one person only. Do not allow other persons in
the work area.
Use extreme caution with openings, recesses,
etc., someone could be standing behind them –
look beforehand.
Never leave a running machine unattended.
When the engine is running: The diamond abra‐
sive chain continues to run for some time after
the throttle trigger has been released – Risk of
injury due to coasting effect!
Beware of slipping on ice, water, snow or uneven
ground!
2 Safety Precautions and Working Techniques English
0458-761-0121-B 5

Don not work while standing on a ladder – not on
an insecure support – not over your shoulder
height – not with one hand only – risk of accident!
Keep clear the working area – bear in mind
obstacles, holes and pitches.
Do not work alone – keep within calling distance
of others in case help is needed.
Be particularly alert and cautious when wearing
hearing protection because your ability to hear
warnings (shouts, alarms, etc.) is restricted.
Take breaks when you start getting tired or feel‐
ing fatigue – risk of accidents!
Keep easily combustible materials away from hot
exhaust gases and hot mufflers – risk of fire!
Mufflers with catalytic converters can become
especially hot.
As soon as the engine is running, the
power machine generates toxic
exhaust gas. These gases may be
odorless and invisible and may con‐
tain unburned hydrocarbons and ben‐
zene. Never run the engine indoors or
in poorly ventilated locations, even if
your model is equipped with a cata‐
lytic converter.
To reduce the risk of serious or fatal injury from
breathing toxic fumes, ensure proper ventilation
when working in trenches, hollows or other con‐
fined locations. This reduces the risk of serious
or fatal injury from breathing toxic fumes.
Stop work immediately if you start suffering from
nausea, headaches, impaired vision (e.g. your
field of vision gets smaller), impaired hearing,
dizziness, or impaired concentration – these
symptoms may possibly be the result of too-high
exhaust gas concentration – Risk of accidents!
To reduce the risk of fire, do not smoke while
operating or standing near your power tool. Com‐
bustible fuel vapor may escape from the fuel sys‐
tem.
Examine the diamond abrasive chain periodically
at short intervals, check that they are not
cracked, chipped, check also that there are no
damaged or missing segments, signs of over‐
heating (discoloration).
Never use diamond abrasive chains that are
cracked or have chipped segments. contact your
servicing dealer.
In the event of noticeable changes in cutting
behavior (e. g., increased vibration, reduced cut‐
ting performance), stop work and eliminate the
causes of the changes.
–Switch off the engine and wait until the dia‐
mond abrasive chain is stationary
–Check condition and correct tension of dia‐
mond abrasive chain
–Ensure that the cutting blades are sharp
Never touch the diamond abrasive chain when
the motor is running. If the diamond abrasive
chain becomes jammed by an object, switch off
the engine immediately before attempting to
remove the object – risk of injury!
To change the diamond abrasive chain, switch
off the engine – risk of injury!
If your power 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 – see also
"Before Starting". Check in particular that the fuel
system has no leaks and the safety equipment is
fully operative. Do not continue operating your
power tool if it is damaged. In case of doubt, con‐
tact a dealer.
Check for correct idling, so that the diamond
abrasive chain stops moving when the throttle
trigger is released. Check and correct the idle
speed setting at regular intervals. Have the
machine repaired by a STIHL servicing dealer if
the diamond abrasive chain continues to run
nevertheless.
2.9 Reactive forces
The most frequently occurring reactive forces are
pull-in and pushback.
2.9.1 Pull-in (A)
2411BA001 KN
A
When the diamond abrasive chain on the bottom
of the guide bar – overbucking – is jammed or
encounters a solid object, the concrete cutter
may suddenly be drawn forward to the work‐
piece.
English 2 Safety Precautions and Working Techniques
6 0458-761-0121-B

2.9.2 Pushback (B)
2411BA002 KN
B
When the diamond abrasive chain on the top of
the guide bar – underbucking – is jammed or
encounters a solid object, the concrete cutter
may suddenly be pushed straight back toward
the operator
002BA146 KN
–Do not allow the guide bar to become jammed
–Always be aware that the object to be cut may
move and other factors may cause the cut to
close and jam the diamond abrasive chain
–The object to be cut must be secured and sup‐
ported so that the cut remains open during
and after cutting
–Do not twist the guide bar in the cut
2.10 Working – cutting off
Ensure sufficient water supply to diamond abra‐
sive chain – do not allow diamond abrasive chain
to run dry.
Always make wet cuts – regardless of the mate‐
rial to be cut.
The diamond abrasive chain must be guided
straight in the cut, without wedging. Never exert
lateral pressure on the diamond abrasive chain.
Do not use for lateral grinding or scrubbing.
Do not operate your saw with the starting throttle
lock engaged. Engine speed cannot be control‐
led with the throttle trigger in this position.
Examine the workplace. Avoid all danger due to
damaged piping or electrical wiring.
The machine must not be used near inflammable
substances or gases.
Do not cut into pipes, metal tanks or other con‐
tainers if you are not sure that they do not con‐
tain any volatile or inflammable substances.
Never leave the machine unattended with the
engine running. Stop the engine before leaving
the machine unattended (e. g. for breaks).
Work calmly and carefully – in daylight conditions
and only when visibility is good. Ensure you do
not endanger others – stay alert at all times.
2411BA003 KN
Make certain that all parts of your body are well
clear of the extended range of travel of the dia‐
mond abrasive chain.
The diamond abrasive chain must be running
when you pull the concrete cutter out of the
object being cut.
Only use the concrete cutter for cutting – not for
prying off or shoveling away objects.
Always decide the cutting direction before posi‐
tioning the concrete cutter. After that, do not
change the cutting direction. Never push or hit
with the device into the cutting gap – do not let
the concrete cutter fall into the cutting depth –
risk of breakage!
If cutting performance begins to deteriorate,
check the sharpness of the diamond abrasive
chain, resharpen as needed. To do this, briefly
cut through abrasive material, e. g., sandstone,
aerated concrete or asphalt.
When working at heights:
–Always use a lift bucket
–Never use the machine while standing on a
ladder
–Never work on an insecure support
–Never work above shoulder height
–Never use the machine with just one hand
Begin cutting with the concrete cutter at full throt‐
tle.
2 Safety Precautions and Working Techniques English
0458-761-0121-B 7

At the end of the cut, the concrete cutter is no
longer supported by the cutting attachment in the
cut. The user must bear the weight of the
machine – risk of loss of control!
Keep water and sludge away from alive electrical
cables – risk of electric shock!
2.11 Vibrations
Prolonged use of the power tool may result in
vibration-induced circulation problems in the
hands (whitefinger disease).
No general recommendation can be given for the
length of usage because it depends on several
factors.
The period of usage is prolonged by:
–Hand protection (wearing warm gloves)
–Work breaks
The period of usage is shortened by:
–Any personal tendency to suffer from poor cir‐
culation (symptoms: frequently cold fingers,
tingling sensations).
–Low outside temperatures.
–The force with which the handles are held (a
tight grip restricts circulation).
Continual and regular users should monitor
closely the condition of their hands and fingers. If
any of the above symptoms appear (e.g. tingling
sensation in fingers), seek medical advice.
2.12 Maintenance and repairs
The machine must be serviced regularly. Do not
attempt any maintenance or repair work not
described in the Instruction Manual. All other
work should be carried out by a servicing dealer.
STIHL recommends that maintenance and repair
work be carried out only by authorized STIHL
dealers. STIHL dealers receive regular training
and are supplied with technical information.
Use only high-quality spare parts. Otherwise,
there may be a risk of accidents or damage to
the machine. Contact a servicing dealer if in
doubt.
STIHL recommends the use of genuine STIHL
spare parts. Such parts have been optimized for
the machine and the user's requirements.
Before starting any maintenance or repair work
and before cleaning the machine, always stop
the engine – risk of injury! – Exception: adjust‐
ment of carburetor and idle speed.
To reduce the risk of fire due to ignition outside
the cylinder, move the slide control to STOP or 0
before turning the engine over on the starter with
the spark plug boot removed or the spark plug
unscrewed.
Do not service or store the machine near a
naked flame – risk of fire due to the fuel.
Check fuel cap regularly for tightness.
Use only spark plugs that are in perfect condition
and have been approved by STIHL – see "Speci‐
fications".
Inspect ignition lead (insulation in good condi‐
tion, secure connection).
Check that the muffler is in perfect working con‐
dition.
Do not use the machine if the muffler is damaged
or missing – risk of fire! – Hearing damage!
Never touch a hot muffler – risk of burns!
The condition of the antivibration elements influ‐
ences vibration behavior – inspect antivibration
elements periodically.
2.12.1 Switch off the engine
–to check the chain tension
–to retension the chain
–to change chains
–for remedying malfunctions
3 Sample Applications
Use diamond abrasive chain only with
water. Connect concrete cutter to
water supply network (min. 1.5 bar).
The water introduced is used to cool the dia‐
mond abrasive chain and rinse the cutting
attachment, and for binding dust.
After finishing work, run the concrete cutter for a
few seconds with water and at operating speed
to rinse the cutting attachment.
If the water pressure or water volume is too low,
this leads to significantly increased wear and
irreparable damage to the cutting attachment –
danger of breakage!
3.1 Objects to be cut
–Must be fully supported
–Must be secured so it cannot roll or slip off
–Must be prevented from vibrating
English 3 Sample Applications
8 0458-761-0121-B

3.2 Severed 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 sepa‐
rated in position. Break these ridges later.
Before finally separating the part, determine:
–how heavy the part is
–how it can move after separation
–whether it is under tension
When breaking out the part, do not endanger
assistants.
3.3 Plunge-cutting
Begin cutting with the concrete cutter at full throt‐
tle.
3.
2411BA004 KN
1.
2.
1.Apply the lower portion of the guide bar
nose2.Swing slowly into the plunge-cutting posi‐
tion3.Make the plunge cut very carefully
When making the plunge cut into existing, nar‐
rower joints, proceed with extreme care.
3.4 Cut in several passes
A
2411BA005 KN
► Mark cutting line (A)
2411BA006 KN
► Work along the cutting line. When making cor‐
rections, do not tilt the diamond abrasive
chain, always reposition it afresh
3.5 Cutting round and hollow bod‐
ies
2411BA007 KN
► Secure pipes, round bodies, etc. against roll‐
ing away
► Mark a cutting line - when determining the cut‐
ting line, avoid reinforcement, especially in the
direction of the severing cut
► Make the plunge cut very carefully
► 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
3.6 Shaping pipe
3 Sample Applications English
0458-761-0121-B 9

► Secure pipes, round bodies, etc. against roll‐
ing away
► Mark a cutting line - when determining the cut‐
ting line, avoid reinforcement, especially in the
direction of the severing cut
DANGER
Manual cutting along this line requires particular
caution and precision.
2411BA008 KN
► Cut into pipes, round bodies, etc. in the area
at the ends of the cutting line, so that the
material does not break away
► Make 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 nec‐
essary, leave small ridges that hold the part
that is to be separated in position. Break these
ridges later
4 Cutting Attachment
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.
2411BA009 KN
1
2
3
a
t = a : 2
–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 abra‐
sive chain (1) must be matched to the groove
width of the guide bar (3)
When pairing components that are not compati‐
ble with each other, the cutting attachment may
become damaged beyond repair after only a
short period of operation.
4.1 Diamond abrasive chain
The correct use of the STIHL diamond abrasive
chain ensures economical use and avoids accel‐
erated wear.
The STIHL diamond abrasive chain is suitable
for cutting the following materials:
–Concrete
–Reinforced concrete
–General blocks
–Masonry
–Stone pipes
–Ductile cast iron pipes
–Abrasive stone*, e.g. asphalt and bricks (sand‐
stone)
–Hard stone*, granite*
*) Restrictions on power and service life are pos‐
sible
Do not cut any other materials – risk of accident!
4.2 Chain scabbard
The product contents includes a chain scabbard
that is suitable for the bar and chain.
5 Mount Guide Bar and Dia‐
mond Abrasive Chain
5.1 Removing the chain sprocket
cover
11
2411BA011 KN
2
► Unscrew nuts (1) from the studs – nuts are
fastened to the chain sprocket cover so that
they are secured against loss
► Remove the chain sprocket cover (2)
English 4 Cutting Attachment
10 0458-761-0121-B

4
2411BA012 KN
3
► Turn the screw (3) to the left until the tensioner
slide (4) butts against the left end of the hous‐
ing slot
5.2 Fit diamond abrasive chain
2411BA013 KN
► Fit the diamond abrasive chain starting at the
nose of the guide bar
4
11
2411BA014 KN
► Position 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.
NOTICE
Diamond abrasive chain 36 GGM can be moun‐
ted in any orientation.
► Position the right locating hole (2) over the peg
of the tensioner slide – simultaneously place
the diamond abrasive chain over the sprocket
wheel (3)
► Turn screw (4) to the right until there is very lit‐
tle diamond abrasive chain sag on the under‐
side of the bar and the lugs of the drive links
engage in the bar groove
► Refit the sprocket cover and screw on the nuts
only fingertight.
► Go to chapter "Tensioning the diamond abra‐
sive chain"
5.3 Moving the guide bar
Only move the guide bar if the diamond abrasive
chain cannot be tensioned properly.
► Removing the chain sprocket cover
► Remove guide bar with diamond abrasive
chain
► Fit the diamond abrasive chain starting at the
nose of the guide bar
4
11
2411BA049 KN
► Position the guide bar over the bolts (1) – align
drive links so that the position lines up with the
symbol (arrow)
5 Mount Guide Bar and Diamond Abrasive Chain English
0458-761-0121-B 11

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.
NOTICE
Diamond abrasive chain 36 GGM can be moun‐
ted in any orientation.
► Position the left locating hole (5) over the peg
of the tensioner slide – simultaneously place
the diamond abrasive chain over the sprocket
wheel (3)
► Turn screw (4) to the right until there is very lit‐
tle diamond abrasive chain sag on the under‐
side of the bar and the lugs of the drive links
engage in the bar groove
► Refit the sprocket cover and screw on the nuts
only fingertight.
► Go to chapter "Tensioning the diamond abra‐
sive chain"
6 Tension Diamond Abrasive
Chain
1
2411BA0015 KN
Re-tensioning during cutting work:
► Shut off the engine
► Wear work gloves to protect your hands
► Loosen nuts
► Raise the guide bar at the nose
► Use the screwdriver to turn the screw (1) to
the right to distance (a) = approx. 5 mm
If the distance (a) = approx. 5 mm cannot be set
due to an elongated diamond abrasive chain,
move guide bar – see installing "Guide bar and
diamond abrasive chain".
► Raise the guide bar further and tighten the
nuts securely
2411BA0045 KN
► Check tension of diamond abrasive chain –
diamond abrasive chain can be pulled across
the guide bar by hand
A new diamond abrasive chain will need to be
retensioned more frequently than one that has
already been in use for an extended period.
► Check chain tension frequently – see chapter
on "Operating Instructions"
7 Check Tension of Diamond
Abrasive Chain
a
2411BA016 KN
► Shut off the engine
► Diamond abrasive chain can sag a maximum
of a = 15 mm
► Retension diamond abrasive chain if neces‐
sary – see "Tensioning the diamond abrasive
chain".
If the diamond abrasive chain sags too much,
this leads to significantly increased wear of the
cutting attachment.
A new diamond abrasive chain will need to be
retensioned more frequently than one that has
already been in use for an extended period.
► Check chain tension frequently – see chapter
on "Operating Instructions"
8 Fuel
Your engine requires a mixture of gasoline and
engine oil.
English 6 Tension Diamond Abrasive Chain
12 0458-761-0121-B

WARNING
For health reasons, avoid direct skin contact with
gasoline and avoid inhaling gasoline vapor.
8.1 STIHL MotoMix
STIHL recommends the use of STIHL MotoMix.
This ready-to-use fuel mix contains no benzol or
lead, has a high octane rating and ensures that
you always use the right mix ratio.
STIHL MotoMix uses STIHL HP Ultra two-stroke
engine oil for an extra long engine life.
MotoMix is not available in all markets.
8.2 Mixing Fuel
NOTICE
Unsuitable fuels or lubricants or mix ratios other
than those specified may result in serious dam‐
age to the engine. Poor quality gasoline or
engine oil may damage the engine, sealing rings,
hoses and the fuel tank.
8.2.1 Gasoline
Use only high-quality brand-name gasoline with
a minimum octane rating of 90 – leaded or unlea‐
ded.
Gasoline with an ethanol content of more than
10% can cause running problems in engines with
a manually adjustable carburetor and should not
be used in such engines.
Engines equipped with M-Tronic deliver full
power when run on gasoline with an ethanol con‐
tent of up to 25% (E25).
8.2.2 Engine Oil
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.
8.2.3 Mix Ratio
STIHL 50:1 two-stroke engine oil: 50 parts gaso‐
line to 1 part oil
8.2.4 Examples
Gasoline STIHL engine oil 50:1
Liters Liters (ml)
1 0.02 (20)
5 0.10 (100)
10 0.20 (200)
15 0.30 (300)
20 0.40 (400)
25 0.50 (500)
► Use a canister approved for storing fuel. Pour
oil into canister first, then add gasoline and
mix thoroughly.
8.3 Storing Fuel
Store fuel only in approved safety-type fuel can‐
isters in a dry, cool and safe location protected
from light and the sun.
Fuel mix ages – only mix sufficient fuel for a few
weeks work. Do not store fuel mix for longer than
30 days. Exposure to light, the sun, low or high
temperatures can quickly make the fuel mix
unusable.
STIHL MotoMix may be stored for up to 2 years
without any problems.
► Thoroughly shake the mixture in the canister
before fueling your machine.
WARNING
Pressure may build up in the canister – open it
carefully.
► Clean the fuel tank and canister from time to
time.
Dispose of remaining fuel and cleaning fluid
properly in accordance with local regulations and
environmental requirements.
9 Fueling
9.1 Preparations
► Before fueling, clean the filler cap and the area
around it to ensure that no dirt falls into the
tank.
► Position the machine so that the tank cap
faces up.
9 Fueling English
0458-761-0121-B 13

WARNING
Never use a tool to open the bayonet-type fuel
cap. This may damage the cap and cause fuel
leakage.
9.2 Open the cap.
2411BA054 KN
2.
1.
► Press the cap down as far as stop, turn it
counterclockwise (about 1/8 turn) and remove.
9.3 Filling Up with Fuel
Take care not to spill fuel while fueling and do
not overfill the tank. STIHL recommends you use
the STIHL filler nozzle for fuel (special acces‐
sory).
9.4 Closing the Cap
2411BA055 KN
2.
1.
► Place the cap on the tank opening and turn it
until it slips into position.
► Press the cap down by hand as far as stop
and turn it clockwise (about 1/8 turn) until it
engages.
9.5 Checking Security of Cap
2411BA056 KN
► Grip the cap – it is properly locked if it cannot
be pulled off and the marks (arrows) on the
cap and fuel tank are in line.
If the cap can be pulled off or the marks are not
in line, refit it – see sections on “Closing the Cap”
and “Checking Security of Cap”.
9.6 Change the Fuel Pickup Body
Every Year
2411BA019 KN
► Drain the fuel tank.
► Use a hook to pull the fuel pickup body out of
the tank and take it off the hose.
► Push the new pickup body into the hose.
► Place the pickup body in the tank.
English 9 Fueling
14 0458-761-0121-B

10 Starting / Stopping the
Engine
10.1 The four positions of the Mas‐
ter Control lever
STOP
0
001BA140 KN
STOP or 0 – engine off – ignition is switched off
Normal run position F – engine runs or can fire
Warm start (n ) – this position is used to start a
warm engine.
Cold start (l) – this position is used to start a
cold engine.
10.2 Adjust Master Control lever
The throttle trigger lockout and throttle trigger
must be pressed simultaneously to adjust the
Master Control lever from Run F to Cold start l.
To set the Master Control lever to Warm start n,
first set it to Cold start l, then push the Master
Control lever to the Warm start n position.
The change to Warm start (n) is only possible
from the Cold start position (l).
When the throttle trigger is squeezed, the Master
Control lever returns from Warm start n to
Run F.
To switch off the engine, set the master control
lever to STOP or 0.
10.2.1 Position choke shutter closed l
–if the engine is cold
–if the engine stalls during opening of throttle
after starting
–if the fuel tank was run until empty (engine
stopped)
10.2.2 Position starting acceleration n
–if engine is warm (once the engine has been
running for approx. one minute)
–when Engine Begins to Fire
–after ventilation of the combustion chamber, if
the engine was flooded
10.3 Connect concrete cutter to
water supply network
2411BA025 KN
► Connect concrete cutter to water supply net‐
work (min. 1.5 bar at 6 l/min).
► Before starting, open shut-off valve (arrow)
completely
10.4 Hold concrete cutter
There are two ways to hold the concrete cutter
during starting.
10 Starting / Stopping the Engine English
0458-761-0121-B 15

10.4.1 On the ground
2411BA020 KN
► Place the concrete cutter securely on the
ground – ensure your footing is firm – the dia‐
mond abrasive chain must not be touching any
objects or the ground.
► Press the concrete cutter firmly against the
ground, holding the front handle with your left
hand, with thumb wrapped round the handle
► place your right foot through the rear handle.
10.4.2 Between knees
0001BA021 KN
► clamp the rear handle between the knees or
thighs
► Hold the front handle firmly with your left hand
– your thumb should be under the handle.
10.5 Actuating
2411BA022 KN
English 10 Starting / Stopping the Engine
16 0458-761-0121-B

► Pull the starter grip slowly with your right hand
until you feel it engage – and then give it a
brisk strong pull and push down the front han‐
dle at the same time. Do not pull out the
starter rope to full length – it might otherwise
break. Do not let the starter grip snap back.
Guide it slowly back into the housing so that
the starter rope can rewind properly.
10.6 Starting the concrete cutter
Before starting, open the shut-off cock fully so
that water flows to the diamond abrasive chain –
never allow chain to run dry.
10.6.1 Decompression valve
2411BA023 KN
► Press the button, the decompression valve will
be opened
The decompression valve closes as soon as the
engine fires. For this reason you must press in
the button before each starting attempt.
WARNING
There must not be anyone within the swivel
range of the concrete cutter.
2
1
2411BA024 KN
STOP
► Simultaneously press the throttle trigger lock‐
out (2) and throttle trigger (3) – set master
control lever
Position choke shutter closed l
–if engine is cold (even if the engine has stalled
during opening of throttle after starting)
Position starting acceleration n
–if engine is warm (once the engine has been
running for approx. one minute).
► Hold and start the concrete cutter.
10.7 When Engine Begins to Fire
1
2411BA026 KN
STOP
► Move the Master Control leve (1) to the posi‐
tion warm start n
10 Starting / Stopping the Engine English
0458-761-0121-B 17

► Press in button to open the decompression
valve.
► Hold and continue cranking the concrete cut‐
ter.
10.8 As Soon As the Engine Runs
2
1
2411BA027 KN
STOP
► Briefly press the throttle trigger (2); the master
control lever (1) jumps to Run F and the
engine begins to idle.
The concrete cutter is now ready for use.
10.9 At Very Low Outside Tempera‐
tures
► Let the engine warm up briefly with the throttle
slightly open.
10.10 Shut off the engine
► Set master control lever to STOP or 0
10.11 If Engine Does Not Start
The master control lever was not returned to its
Warm start n position in time when the engine
turned over for the first time and the engine has
now flooded.
► Remove the spark plug – see "Spark Plug".
► Dry the spark plug
► Set master control lever to STOP or 0
► Crank the engine several times with the starter
to clear the combustion chamber.
► Refit the spark plug – see "Spark Plug".
►Set master control lever to Warm start n –
even if the engine is cold.
► Restart the engine.
10.11.1 Wet filter
► Dry wet filter if necessary – do not expose to
extreme heat.
► If the filter is very dirty, clean the filter thor‐
oughly – see "Cleaning the air filter"
11 Operating Instructions
11.1 During the break-in period
A factory new machine should not be run at high
revs (full throttle off load) for the first three tank
fillings. This avoids unnecessarily high loads dur‐
ing the break-in period. As all moving parts have
to bed in during the break-in period, the frictional
resistances in the shortblock are greater during
this period. The engine develops its maximum
power after about 5 to 15 tank fillings.
11.2 During work
CAUTION
Always work with water.
CAUTION
Do not make the mixture leaner to achieve an
apparent increase in power – this could damage
the engine – see "Adjusting the Carburetor".
11.2.1 Check chain tension frequently
The diamond abrasive chain stretches and
begins to sag. The drive links on the underside of
the bar must not come out of the bar groove by
more than 15 mm – the diamond abrasive chain
may otherwise jump off the bar – retension the
diamond abrasive chain – see "Tensioning the
diamond abrasive chain".
If the diamond abrasive chain sags too much,
this leads to significantly increased wear of the
diamond abrasive chain and chain sprocket –
retension the diamond abrasive chain – see
"Tensioning the diamond abrasive chain".
A new diamond abrasive chain must be reten‐
sioned more frequently than one that has been in
use already for an extended period.
11.2.2 After a long period of full-throttle oper‐
ation
After a long period of full-throttle operation, allow
engine to run for a while at idle speed so that the
heat in the engine can be dissipated by flow of
cooling air. This protects engine-mounted com‐
ponents (ignition, carburetor) from thermal over‐
load.
English 11 Operating Instructions
18 0458-761-0121-B

11.3 After finishing work
11.3.1 Short-term storage
Wait for engine to cool down. Keep the machine
with a full tank of fuel in a dry place, well away
from sources of ignition, until you need it again.
Clean and dry guide bar and diamond abrasive
chain, and spray with STIHL multispray – in par‐
ticular the bearing of the sprocket nose – corro‐
sion protection. Do not spray engine unit!
11.3.2 Long-term storage
See "Storing the machine"
12 Air Filter System
When dry, STIHL filters attain a long service life.
► Always use STIHL filters dry
Fouled air filters will impair engine performance,
increase fuel consumption and make the
machine more difficult to start.
13 Remove Air Filter
2411BA030 KN
► Turn screw plug above the rear handle in the
direction of the arrow and remove filter cover –
screw plug is secured in the filter cover
2411BA031 KN
► Detach the air filter
Do not remove and clean the auxiliary filter.
14 Cleaning the Air Filter
If there is a noticeable loss of engine power:
► Dry wet air filter if necessary – do not expose
to extreme heat
► If the air filter is very dirty, clean the filter thor‐
oughly
Thorough filter cleaning
► Wash the air filter in STIHL special-purpose
cleaner (special accessory) or a clean, non-
flammable cleaning liquid (e. g., warm soapy
water) – rinse the air filter from inside to out
under a water flow – do not use high-pressure
washers
► Dry the air filter – do not expose to extreme
heat, do not dry with compressed air
► Do not oil the air filter
► Reinstall air filter
Always replace a damaged air filter.
15 Adjusting the Carburetor
15.1 General Information
The carburetor comes from the factory with a
standard setting.
This setting provides an optimum fuel-air mixture
under most operating conditions.
With this carburetor it is only possible to correct
the adjusting screws within fine limits.
The ignition module limits maximum engine
speed. Therefore, maximum engine speed can‐
not be increased by turning the high speed
screw (H) any further clockwise (leaner).
15.2 Standard Setting
► Shut off the engine.
► Check the air filter and clean or replace if nec‐
essary.
3443BA001 KN
► Turn high speed screw (H) counterclockwise
as far as stop (no more than 3/4 turn).
► Turn the low speed screw (L) clockwise as far
as stop, then turn it back 1/4 turn.
12 Air Filter System English
0458-761-0121-B 19

15.3 Adjusting Idle Speed
Before starting, open the shut-off cock fully so
that water flows to the diamond abrasive chain –
never allow chain to run dry.
► Carry out the standard setting.
► Start and warm up the engine.
3443BA002 KN
15.3.1 Engine stops while idling or chain runs
while engine is idling
► Turn the idle speed screw (LA) clockwise as
far as stop or until the chain begins to run –
then turn the screw back 1 1/2 turns.
WARNING
If the chain continues moving when the engine is
idling, have your machine checked and repaired
by your servicing dealer.
15.3.2 Erratic idling behavior, poor accelera‐
tion (even though low speed screw is
open 1/4 turn)
3443BA003 KN
Idle setting is too lean
► Turn the low speed screw (L) counterclock‐
wise until the engine runs and accelerates
smoothly.
It is usually necessary to change the setting of
the idle speed screw (LA) after every correction
to the low speed screw (L).
15.4 Fine Tuning for Operation at
High Altitude
A slight correction of the setting may be neces‐
sary if engine does not run satisfactorily:
► Carry out the standard setting.
► Warm up the engine.
► Turn high speed screw (H) slightly clockwise
(leaner) – no further than stop.
NOTICE
After returning from high altitude, reset the car‐
buretor to the standard setting.
If the setting is too lean there is a risk of engine
damage due to insufficient lubrication and over‐
heating.
16 Spark Plug
► If the engine is down on power, difficult to start
or runs poorly at idle speed, first check the
spark plug.
► Fit a new spark plug after about 100 operating
hours – or sooner if the electrodes are badly
eroded. Install only suppressed spark plugs of
the type approved by STIHL – see "Specifica‐
tions".
16.1 Remove the spark plug
► Remove coarse dirt from the machine
2411BA030 KN
► Turn screw plug above the rear handle in the
direction of the arrow and remove filter cover –
screw plug is secured in the filter cover
English 16 Spark Plug
20 0458-761-0121-B