Cobra Combi Maintenance and service guide

© 2005 Atlas Copco Construction Tools AB | No 9800 0636 90 | 2005-09-16
COMBI & STANDARD
COBRA
Safety and operating instructions
Petrol drills and breakers
Prescriptions de securité et Instructions
pour l’opérateur
Marteaux-perforateurs
Sicherheitsvorschriften und
Bedienungsanleitung
Bohrer und Meißel mit Benzinmotor
Instrucciones de seguridad y para el
operario
Perforadores y rompedores de gasolina
Instrucoes de seguranca o instrucoes de
operacao
Máquinas de perfuração petrolífera e de
demolição
Manuale di istruzioni sulla sicurezza per
l’uso dei
Perforatori/demolitori a motore
Veiligheidsinstrukties en
beidieningsinstrukties
Benzinegedreven boor- en sloophamer
Οδηγίες ασφάλειας και λειτουργίας
Βενζινοκίνητες σφύρες και κρουστικά
μηχανήματα
Turvallisuusohjeet ja käyttöohje
Polttonesteporat ja –murskaimet
Sikkerhedsinstruktioner og
betjeningsvejledning
Benzindrevne bor og mejselhamre
Sikkerhetsinstrukser og bruksanvisning
Motorboremaskiner og spett
Säkerhetsinstruktion och instruktionsbok
Bensindrivna borrar och spett
COBRA COMBI
COBRA STANDARD

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Cobra Combi & Standard
© 2005 Atlas Copco Construction Tools AB | No 9800 0636 90 | 2005-09-16
Safety and operating instructions

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Cobra Combi & Standard
© 2005 Atlas Copco Construction Tools AB | No 9800 0636 90 | 2005-09-16
Contents
CONTENTS
English. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Français. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Deutsch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Español . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Português . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Italiano. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Nederlands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Ελληνικά . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Suomi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Dansk. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
Norsk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
Svenska. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

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Cobra Combi & Standard
© 2005 Atlas Copco Construction Tools AB | No 9800 0636 90 | 2005-09-16
Contents
CONTENTS ENGLISH
SAFETY INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Safety symbols used. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Machine and tool operating hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Fume and exhaust hazard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Explosion and fire hazard. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Explosion and fire hazard, continued . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Electrical/Concealed object hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Projectile hazard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Noise hazard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Silica/Dust hazard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Vibration hazard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Machine modification hazard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Additional safety instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Protective equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Service and maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Machine tools. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
OPERATING INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Design and function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Main parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Preparations before starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Tool shank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Two-stroke oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Starting and stopping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Cold start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Restarting a warm machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Number of revs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Ground probing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Stopping the engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Drilling (Cobra Combi) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Flushing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Inserting the tool. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Function selector: Drilling and breaking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Drilling deep holes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Regular care. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Air filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Gas duct . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Decals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Spark plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Changing the starting cord . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Fitting a new cord . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Tool chuck . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Carburettor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Trouble shooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Scrapping worn-out machines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Cobra Combi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Cobra Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Noice and Vibration Declaration Statement . . . . . . . . . . . . . . . . . . . . . . . . . . 16
ENGLISH

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Cobra Combi & Standard
© 2005 Atlas Copco Construction Tools AB | No 9800 0636 90 | 2005-09-16
Safety and operating instructions
SAFETY INSTRUCTIONS
To reduce risk of serious injury or death to yourself
or others, read these safety instructions before
operating the machine.
Post these safety instructions at work locations,
provide copies to employees, and make sure that
everyone reads the safety instructions before
operating or servicing the machine.
Comply with all safety regulations.
Safety symbols used
The indications Danger, Warning and Caution
have the following meanings:
Danger Indicates an imminently
hazardous situation which,
if not avoided, will result in
death or serious injury.
Warning Indicates a potentially
hazardous situation which,
if not avoided, could result
in death or serious injury.
Caution Indicates a potentially
hazardous situation which,
if not avoided, may result
in minor or moderate
injury.
Machine and tool operating
hazards
Warning
Sudden or unexpected movement of the machine
may occur during operating, which may cause
injuries. In addition loosing your balance or slipping
may cause injury. To reduce such risks:
Make sure that you always keep a stable
position with your feet as wide apart as your
shoulder width, and keep a balanced body
weight.
Stand firmly and always hold on to the machine
with both hands.
Do not start the machine when it is laying on the
ground.
Make sure that the handles are clean and free of
grease and oil.
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Warning
Unintended start of the machine may cause injury.
Keep your hands away from the start and stop
device until you are about to start work.
Warning
The insertion tool is exposed to heavy strains
when the machine is used and after a certain
amount of use the tool may break due to fatugue.
If the tool breaks, there may be sudden or strong
movements. Such sudden or strong movements
may cause serious injury.
Make sure that you always keep a stable
position with your feet as wide apart as your
shoulder width, and keep a balanced body
weight.
Keep your feet away from the insertion tool.
Do not ’ride’ on the machine with one leg over
the handle, since you could be seriously injured
if the tool suddenly were to break.
Check regulary for any wear on the insertion
tool, and if there are any risks of damages or
fractures.
Do not use worn out or damaged insertion tools.
Warning
Incorrrect dimension of the insertion tool's shank
can result in that the insertion tool may be dropped
or ejected. A dropped or ejected insertion tool can
cause personal injury.
Before the insertion tool is mounted, make sure
that the shank is correct for the machine.
An insertion tool without a collar should not be
used.
Warning
If the insertion tool retainer on the machine is not in
a locked position, the tool can be ejected with great
force, which can cause serious injury.
After the insertion tool is mounted and locked,
the lock function must be checked by pulling the
insertion tool powerful.
Make sure that the tool is fully inserted and the
tool retainer is in a locked position before the
machine is started.
Warning
Changing the inserted tool while the machine is
running may cause serious injury.
Before changing the insertion tool, always stop
the machine and close down the machine by
pushing the start and stop device.
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Cobra Combi & Standard
© 2005 Atlas Copco Construction Tools AB | No 9800 0636 90 | 2005-09-16
Safety and operating instructions
Warning
The exhaust pipe and the bottom of the machine
can become very hot during operation, and
can remain hot during a period of time after the
machine has been shut off.
To reduce the risk of burns or related injuries,
avoid contact with the exhaust pipe or the
bottom of the machine.
Warning
If the drill steel gets caught during operation, the
whole machine will start to rotate if you lose your
grip. Such an unexpected rotation of the entire
machine may cause serious injury.
Stand firmly and always hold the machine with
both hands.
Make sure that the handles are clean and free
of grease and oil.
Never drill in an old hole.
Warning
There is a risk of objects getting dragged into or
getting caught by a rotating drill steel. This may
cause serious injury.
Never grab or touch a rotating drill steel.
Avoid wide cloths that may get caught.
If you have long hair, cover with a hair net.
Fume and exhaust hazard
Danger
The exhaust fumes from the machine’s combustion
engine contain carbon monoxide which is
poisonous. Inhalation of exhaust fumes can cause
serious injury or death.
Do not inhale exhaust fumes.
Never operate the machine indoors or in poorly
ventilated areas.
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Explosion and fire hazard
Danger
If the machine comes in contact with explosives,
an explosion may occur. Explosions may cause
serious injury or death.
To reduce risk of explosion:
Never drill or operate the equipment near
any explosives, including dynamite or other
explosives in the rock.
Make sure that there are no explosives in the
rock.
Never break or drill in an old hole.
Warning
Breaking, drilling and working with certain
materials can cause sparks, which may ignite
explosive gases which can cause explosions.
Explosions may cause serious injury or death.
To reduce risk of explosion:
Never operate the equipment in any explosive
environments.
Do not use the machine near flammable
materials, fumes or dust.
Make sure that there are no undetected sources
of gas.
Warning
During operation of the machine, the exhaust pipe
gets very hot and may stay hot for a period of time
even after you have shut off the engine. Materials
that come in contact with a hot exhaust pipe may
ignite and cause fire or explosion, which can cause
serious injury. To reduce risk of fire or explosion:
Do not use the machine near flammable
materials, fumes or dust. During breaks in
work, remember not to place the machine near
flammable materials.
Do not operate the machine in explosive
environments.
Keep the workplace clean and free from foreign
objects.
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Cobra Combi & Standard
© 2005 Atlas Copco Construction Tools AB | No 9800 0636 90 | 2005-09-16
Safety and operating instructions
Explosion and fire hazard,
continued
Warning
Fuel is highly flammable, and its vapors can
explode if ignited, which can cause serious injury
or death. To reduce risk of fire or explosion:
Store fuel only in containers that are specifically
designed and approved for storage of fuel.
Empty fuel containers must be properly taken
care of and sent back to the retailer.
Operate the machine with the fuel cap securely
in place. Never remove the fuel cap or add fuel
when the engine is hot. Stop the engine and
allow it to cool before adding fuel. When opening
the fuel cap, always loosen the cap slowly to
relieve any pressure in the tank. Do not overfill
the tank.
Always mix and add fuel in a clean and well-
ventilated area. Make sure that this outdoor area
is free from any flames or sparks. Never smoke
while fuelling, mixing fuel, operating or servicing
the machine. Avoid spilling fuel. Wipe up any
fuel that is spilled on the machine. Fill the tank
at least ten meters (30 feet) away from where
you intend to use the machine.
Do not use a machine that is leaking fuel.
Regularly check for any leakage.
To minimize the risk of fuel leakage during
transportation, secure that the machine is in an
upright position during transportation.
Do not use the machine near flammable
materials, fumes or dust. During breaks in
work, do not place the machine near flammable
materials.
Do not operate the machine near any materials
that create sparks. Remove all hot objects
and objects that create sparks prior to using
machine.
Do not operate the machine in an explosive
environment.
Protect your skin from contact with fuel.
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Electrical/Concealed object
hazards
Warning
The machine is not electrically insulated. If the
machine comes in contact with electricity, serious
injuries or death may result.
To reduce the risk of injury or death, never drill
or break near any electric wire or other source of
electricity.
Make sure that there are no concealed wires or
other sources of electricity.
Warning
During drilling and breaking, concealed wires and
pipes constitute a danger that can result in serious
injury.
Before you start drilling or breaking, check the
composition of the material you are to work on.
Watch out for concealed electrical wiring, water,
sewage and gas pipes and phone lines.
If the tool seems to have hit a concealed object,
immediately switch off the machine.
Make sure that there is no danger before
continuing.
Projectile hazard
Warning
During breaking, drilling or hammering, splinters or
other particles of rock may become projectiles and
cause bodily injury by striking the operator or other
persons.
Use approved personal protective equipment,
including impact resistant safety glasses with
side protection, to reduce the risk of being
injured by a projectile.
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Cobra Combi & Standard
© 2005 Atlas Copco Construction Tools AB | No 9800 0636 90 | 2005-09-16
Safety and operating instructions
Noise hazard
Warning
High sound levels may cause permanent hearing
loss.
Use hearing protection in accordance with
occupational health and safety regulations.
Silica/Dust hazard
Warning
Exposure to crystalline silica (sometimes called
“silica dust”) as a result of breaking, drilling, or
hammering of rock, concrete, asphalt or other
materials may cause silicosis (a serious lung
disease), silicosis-related illnesses, cancer, or
death. Silica is a major component of rock, sand
and mineral ores.
To reduce silica exposure:
Use proper engineering controls to reduce the
amount of silica in the air and the build-up of
dust on equipment and surfaces. Examples of
such controls include: exhaust ventilation and
dust collection systems, water sprays, and wet
drilling. Make sure that controls are properly
installed and maintained.
Wear, maintain, and correctly use approved
particulate respirators when engineering controls
alone are not adequate to reduce exposure
below permissible levels.
Participate in air monitoring, medical exams,
and training programs offered by your employer
and when required by law.
Wear washable or disposable protective clothes
at the worksite; shower and change into clean
clothes before leaving the worksite to reduce
exposure of silica to yourself, other persons,
cars, homes, and other areas.
Do not eat, drink, or use tobacco products in
areas where there is dust containing crystalline
silica.
Wash your hands and face before eating,
drinking, or using tobacco products outside of
the exposure area.
Work with your employer to reduce silica
exposure at your worksite.
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Warning
Some dust or other airborne material created
during use of the machine may contain
chemicals known to the State of California
to cause cancer and birth defects or other
reproductive harm. Some examples of such
chemicals are:
Crystalline silica and cement and other masonry
products.
Arsenic and chromium from chemically-treated
rubber.
Lead from lead based paints.
To reduce your exposure to these chemicals,
work in a well ventilated area, and work with
approved safety equipment, such as dust masks
that are specially designed to filter out microscopic
particles.
Vibration hazard
Warning
Repetitive tasks, awkward working positions or
vibrations may cause injury to your fingers, hands,
arms, and other body parts. Exposure to vibrations
may restrict blood supply to the hands and fingers,
which may cause injury. If numbness, tingling,
pain, whitening of the skin, or reduction in feeling
occurs when you use the machine, or even when
you are not using the machine, do not use the
machine and contact a physician.
The inserted tool creates vibrations that may cause
injury. Do not grab, hold, or touch the tool when
using the machine.
Machine modification hazard
Warning
Any machine modification not approved by Atlas
Copco may result in serious injuries to yourself or
others.
The machine must not be modified without Atlas
Copco's permission.
Use only original parts and accessories
approved by Atlas Copco.
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Cobra Combi & Standard
© 2005 Atlas Copco Construction Tools AB | No 9800 0636 90 | 2005-09-16
Safety and operating instructions
Additional safety instructions
Machines and accessories must only be used
for their intended purpose.
Only qualified and trained persons may operate
or maintain the machine.
Keep your hand away from the start and stop
device until work is to begin.
Learn how the machine is switched off in the
event of an emergency.
The machine should be operated at reduced
power when drilling is started.
Release the start and stop device in case of
interruption of the energy supply.
Always inspect the equipment prior to use.
Do not use equipment if you suspect that it
could be damaged.
Check the insertion tools for wear or damages
at regular intervals. Do not use worn out or
damaged insertion tools.
Always use your common sense and good
judgment.
Do not use the machine when you are tired or
under the influence of drugs, alcohol or anything
else that may affect your vision, reactions or
judgement.
Participate in safety and training courses.
Never strike or abuse any equipment.
Keep the machine and tools in a safe and locked
place out of reach of children.
Make sure that the all attached and related
equipment is properly maintained.
Signs and stickers that are important for your
safety and the care of the machine are included
with every machine. New signs and stickers can
be ordered using the spare parts list.
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Protective equipment
Always use approved personal protective
equipment. Operators and other persons in the
work area must wear protective equipment,
including at a minimum:
Protective helmet
Hearing protection
Impact resistant eye protection with side
protection
Respiratory protection when appropriate
Protective gloves
Protective boots
Service and maintenance
Regular maintenance is a prerequisite for keeping
the machine a safe tool. Carefully follow the
operating instructions.
Use only authorized parts. Any damage or
malfunction caused by the use of unauthorized
parts is not covered by Warranty or Product
Liability.
Change damaged parts immediately.
Replace damaged and worn out components in
good time.
For major service to the machine, contact your
nearest authorized Atlas Copco workshop.
When cleaning mechanical parts with solvent,
make sure that current health and safety
regulations are complied and that the ventilation
is satisfactory.
Machine tools
Keep the tools clean and in a good condition.
Check tools regulary and make sure that they
are sharp.
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10
Cobra Combi & Standard
© 2005 Atlas Copco Construction Tools AB | No 9800 0636 90 | 2005-09-16
Safety and operating instructions
OPERATING
INSTRUCTIONS
Design and function
Cobra Combi is a combined drilling and
hammering machine. It is equipped to be used
for breaking asphalt and concrete and for drilling
in concrete and granite.
Cobra Standard is not a combined machine and
is designed for breaking only.
Main parts
A Choke
B Throttle lever
C Vibration-dampened handle
D Engine piston
E Silencer
F Intake valve for flushing air
G Compression chamber for flushing air
H Rotation mechanism
I Tool retainer
J Air filter cover
K Tank cap
L Starting handle
M Power take-off (PTO)
N Spark plug cover
O Percussion piston
P Gas duct
Q Gas duct valve
R Function selector (Cobra Combi)
S Venturi
T Stop-button
U Fuel filter
Preparations before starting
Tool shank
Use a shank gauge to check that the tool shank is of the
correct size, i.e. H 22x108 mm (7/8” x 4 1/4”). The shank
must be clean and the tool must be in good condition.
Fuel
Cobra Combi and Standard use a mixture of petrol and
two-stroke oil, 1 part oil to 50 parts petrol (2%).
Two-stroke oil
For the best lubricating results use Atlas Copco’s
environmentally friendly two-stroke oil, which
has been specially developed for Atlas Copco’s
petrol motor-driven hammering and rock-drilling
machines. If Atlas Copco’s two-stroke oil is not
available, use a high-quality two-stroke oil for
air-cooled two-stroke motors (not two-stroke oil
for outboard motors). Contact your nearest Atlas
Copco representative for advice on the correct
two-stroke oil.

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Cobra Combi & Standard
© 2005 Atlas Copco Construction Tools AB | No 9800 0636 90 | 2005-09-16
Safety and operating instructions
Starting and stopping
A Vibration-dampened handle
B Throttle lever
C Stop button
D Choke
E Fuel filling
F Starting handle
Cold start
Close the choke – turn the choke control
anticlockwise to position (CHOKE)
Push the throttle lever down and pull the
starter handle.
When the machine ignites, open the choke
one step clockwise towards position (RUN).
1.
2.
3.
Pull the starting handle. When the machine
starts, slowly turn the choke clockwise
towards position (RUN) during a 2–3 minutes
warm-up period.
Restarting a warm machine
Check that the choke is open (i.e. knob in
position RUN).
Pull the starter handle.
If the machine stops after a short while, or does
not start at all, follow the procedure for cold
starting.
If the machine does not start, it may have been
flooded (i.e. too much fuel in the combustion
chamber).
Open the choke (RUN position) and try starting
the engine again.
If the machine still does not start, see the
section entitled "Trouble shooting".
Number of revs
The engine speed is regulated by means of the
throttle lever:
Lever released – idling speed
4.
1.
2.
►
►
►
►

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Cobra Combi & Standard
© 2005 Atlas Copco Construction Tools AB | No 9800 0636 90 | 2005-09-16
Safety and operating instructions
Lever depressed – full engine speed
Ground probing
If the machine is started on top of long tools such
as probing rods, a starter-cord bracket must be
used to prevent the cord from damaging the fuel
tank.
Stopping the engine
Stop the engine by depressing the stop button.
Drain the fuel tank before transporting the
machine, drain also the fuel tank when the
machine is not to be used for a long period of
time.
Drilling (Cobra Combi)
Flushing
Before drilling, check that the flushing hole in the drill
steel is not blocked.
►
►
Inserting the tool
Stop the machine. Insert the tool into the chuck and use
your foot to lock the tool retainer.
Function selector: Drilling and breaking
Drilling:
Turn the function
selector downwards.
This will engage
rotation and flushing
air.
Breaking:
To adjust the direction
of the tool blade,
first put the function
selector in the neutral
position.
Locked position:
Lock the tool blade in
the desired position
by turning the selector
upwards. The rotation
mechanism is now
locked.

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Cobra Combi & Standard
© 2005 Atlas Copco Construction Tools AB | No 9800 0636 90 | 2005-09-16
Safety and operating instructions
Collaring
With the engine idling, press the machine and tool
against the spot where you wish to drill. Increase
the engine speed once the drill bit has collared a
footing in the rock (or other material).
Grip the side handle for better control of the
machine.
Drilling deep holes
First use a short drill and then fullly drill into
the hole.
Then change to a longer drill with a slightly
smaller bit diameter (approx. 1 mm smaller).
Regular care
Air filter
In the event of continuous use, check and change
the filter at least every shift.
Unscrew the filter cover.
1.
2.
1.
Carefully strike the filter against the palm of
your hand. Extremely dirty filters must be
replaced. The filter must never be washed.
Gas duct
The gas duct must be checked regularly for carbon
deposits, and cleaned if necessary.
1. Pull the starting handle until the arrow in the
centre of the flywheel (which can be seen
through the fan cover) points upwards. This
indicates that the engine piston is in the upper
position.
2. Unscrew the gas duct valve
and take out the cleaning
rod. Clean the duct and
cleaning rod using the
cleaning needle provided.
3. Clean the cleaning thread
4. Clean the channel using the cleaning needle
provided.
5. Check that the ball in the gas duct valve is not
stuck.
2.

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Cobra Combi & Standard
© 2005 Atlas Copco Construction Tools AB | No 9800 0636 90 | 2005-09-16
Safety and operating instructions
Decals
Replace damaged or worn decals. Order numbers
can be found in the spare-parts list.
Maintenance
Spark plug
Lift the spark plug cover by the lower lip, and
turn it up to one side.
Use a plug spanner to remove the spark
plug.
If the spark plug is dirty or burned, it must be
replaced. Use original Bosch WR7AC spark
plugs.
If the pin has been dampened by fuel, dry
it off, check the ignition spark, and pull the
starter handle 2–3 times to ventilate off any
excess fuel.
Fit the spark plug back into the cylinder.
Note! The electrode gap should be 1.5 mm
(0.060 in.).
1.
2.
3.
4.
5.
Changing the starting cord
Remove the screw-cap of the PTO (See
image under "Main parts"). Remove the three
bolts from the protective cover of the starting
mechanism.
Lift off the cover, grasping the starter pulley
as well. Let the cover rotate carefully against
the starter pulley, to release the spring
tension.
Remove the old starting cord.
Fitting a new cord
Oil the needle bearing in the starter pulley.
Fit together the starter pulley and protective
cover, so that the starting spring locates in
the starter pulley.
Wind the full length of the cord onto the
pulley.
Pre-tension the starting spring by about one
turn (clockwise) before fitting the assembly
into place.
Pull the starting handle carefully, in order to
locate the cover correctly.
Fit and tighten the hexagonal bolts and the
PTO screw-cap.
1.
2.
3.
1.
2.
3.
4.
5.
6.

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Cobra Combi & Standard
© 2005 Atlas Copco Construction Tools AB | No 9800 0636 90 | 2005-09-16
Safety and operating instructions
Tool chuck
If the chuck gauge provided can be inserted
fully across the flats of the hexagonal chuck, this
indicates that the chuck is worn out and must be
replaced.
Carburettor
On delivery the carburettor is adjusted and locked
so it meets EPA’s exhaust-gas standard.
The carburettor nozzle does not normally need to
be adjusted.
Normal setting:
Main nozzle (Cobra Combi Fe-cyl) (1) ........... 1,8 turns open
Idling nozzle (Cobra Combi Fe-cyl) (2)........... 2,1 turns open
Main nozzle (1)............................................... 2,0 turns open
Idling nozzle (2) .............................................. 2,0 turns open
When loaded, the maximum revs should be
2500–2650 rpm. The idling revs should be
1600–1800 rpm.
Trouble shooting
If the engine does not start, is difficult to start, runs
unevenly or has poor output, check the points
mentioned below (See image under "Main parts").
Check that the Stop button (See C under
"Starting and stopping") is in the ON position.
Check the fuel level.
Check the spark plug’s electrode distance.
Check that the air filter is not blocked.
Check that the fuel filter (See U under "Main
parts") is not blocked.
If the machine still does not work satisfactorily
following this procedure, please contact your
nearest authorised Atlas Copco workshop.
Scrapping worn-out
machines
Worn-out machines must be dealt with and
deposited in such a way that the maximum amount
of material can be recycled and the environment is
affected as little as possible.
Note: Before a motor-driven drill is deposited
or thrown-away it must be emptied and
cleaned of petrol. Remaining petrol must
be dealt with in a way which not affects the
environment.
1.
2.
3.
4.
5.

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Cobra Combi & Standard
© 2005 Atlas Copco Construction Tools AB | No 9800 0636 90 | 2005-09-16
Safety and operating instructions
Technical data
Cobra Combi Cobra Standard
Engine
Type 1 cylinder, two-stroke, air
cooled
1 cylinder, two-stroke, air
cooled
Cylinder displacement 185 cc 185 cc
Speed, crankshaft
(strokes/min)
Full speed 2500–2650 r/min
Idling 1600–1800 r/min
Full speed 2500–2650 r/min
Idling 1600–1800 r/min
Carburettor Membran type (Walbro) Membran type (Walbro)
Ignition system Thyristor type, breakerless Thyristor type, breakerless
Spark plug (recommended) Bosch WR7AC Bosch WR7AC
Spark plug gap 1.5 mm (0.060 in.) 1.5 mm (0.060 in.)
Starter Magnapull Magnapull
Fuel type Petrol 90–100 octane,
lead-free only
Petrol 90–100 octane,
lead-free only
Oil type Atlas Copco two-stroke oil or
recommended two-stroke oil
Atlas Copco two-stroke oil or
recommended two-stroke oil
Fuel mixture 2% (1:50) 2% (1:50)
Fuel consumption Approx. 1.1–1.4 litres/hour
(0.29–0.37 US gallons/hour)
Approx. 1.1–1.4 litres/hour
(0.29–0.37 US gallons/hour)
Capacities
Max drilling depth 2 m -
Penetration rate with 29 mm drill bit 250–350 mm/min -
Penetration rate with 34 mm drill bit 200–300 mm/min -
Penetration rate with 40 mm drill bit 150–200 mm/min -
Other data
Tool shank H 22x108 mm H 22x108 mm
Machine weight (Fe-cyl) 29.2 kg
(Al-cyl) 25.6 kg
23.4 kg
Service weiht (machine incl. fuel and tools) (Fe-cyl) 31.4 kg
(Al-cyl) 27.8 kg
25.6 kg
Length 732 mm 694 mm
Width, max 470 mm 470 mm
Noice and Vibration Declaration Statement
Sound effect according to EN ISO 3744 in accordance with directive 2000/14/EG
Lp measured, r = 1m dB (A) rel 20 µPa 100 99
Lw guaranteed dB (A) rel 20 µPa 108 107
Vibration according to EN28662-5
Measured vibration value (a m/s2) 5.0 5.0
Spread in method and production (ka m/s2) 3.5 3.5
These declared values were obtained by laboratory type testing in compliance with the stated standards and are not
adequate for use in risk assessments. Values measured in individual work places may be higher than the declared
values. The actual exposure values and risk of harm experienced by an individual user are unique and depend upon
the way the user works, the workpiece and work station design, as well as upon the exposure time and the physical
condition of the user. We, Atlas Copco Construction Tools AB, cannot be held liable for the consequences of using
the declared values, instead of values reflecting the actual exposure, in an individual risk assessment in a work place
situation over which we have no control.