Cobra BC270KB User manual

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MODELS: BC270KB (PNBC270K) BC270K (PNBC270K) BC350KB
(PNBC350KB) BC350K (PNBC350K) BC450K (PNBC450K)
COBRA BRUSHCUTTER
OWNER’S MANUAL
Cobra Garden Machinery
Henton and Chattell Ltd., London Road,
Nottingham NG2 3HW UK
www.cobragarden.co.uk

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CONTENTS
SECTION 1 Safety Overview ………………………………………………….………. 3
SECTION 2 Parts Descriptions………………………………………………………… 4
SECTION 3 Assembly Instructions….………………………………………………... 5
SECTION 4 Fuel and Oil Recommendations ……………………………………….. 10
SECTION 5 Adjustment of the Throttle Cable.……………………………………….. 10
SECTION 6 Starting Procedure ……………………………………………………… 11
SECTION 7 Warm-up Procedure…………….……………………………………….. 12
SECTION 8 Stopping………………………...……………………………………..….. 13
SECTION 9 Maintenance…………………..…………………………………….…….. 14
SECTION 10 Storage……………………………………….….………………………... 15
SECTION 11 Troubleshooting Guide……………………..……………………..…….. 15
SECTION 12 Warranty…………... ………………………………………………….…...16
SECTION 13 Environment ..………………………………………………………….…. 16
SECTION 14 EC Declaration of Conformity……………………………………….….. 17

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1. Safety Overview
ALL OPERATORS MUST READ THE
INSTRUCTIONS BEFORE USING THE
MACHINERY.
Always follow safe operating and maintenance
practices.
Read the manual before operating the
machinery.
Wear protective head, eye and ear
equipment.
Wear protective foot wear and gloves.
Cover and protect arms and legs.
Never operate machinery when tired, ill or
under the influence alcohol or drugs.
Keep bystanders a safe distance of at least
15m from the operating trimmer.
WARNING: When using petrol tools, basic
safety precautions, including the following, should
always be followed to reduce the risk of serious
personal injury and/or damage to the unit. Read all
these instruction before operating this product and
retain these instructions for future reference.
WARNING: This machine produces an
electromagnetic field during operation. This field
may under some circumstances interfere with active
or passive medical implants. To reduce the risk of
serious or fatal injury, we recommend persons with
medical implants to consult their physician and the
medical implant manufacturer before operating this
machine.
Training
1. Before using the trimmer read the instructions
carefully. Familiarise yourself with the controls
and pay particular attention in learning how to
stop the machine in an emergency.
2. Never allow children or people unfamiliar with
these instructions to use the machinery. Local
regulations can restrict the age of the operator.
3. Never operate while people, especially children
or pets are nearby.
4. Never use the trimmer if the operator is taking
medicine or substances that could affect or
impair his ability to react or concentrate.
5. Keep in mind that the operator or user is
responsible for accidents or hazards occurring to
other people or their property.
Before you start
1. While trimming, always wear substantial
footwear and long trousers. Do not operate the
equipment when barefoot or wearing open toed
sandals.
2. Thoroughly inspect the area where the
equipment is to be used and remove all objects
which can damage or be thrown by the
machine.
3. WARNING - Petrol is highly flammable. Store
fuel in containers specifically designed for this
purpose. Refuel outdoors only and do not
smoke while refuelling; add fuel before starting
the engine. Never remove the cap of the fuel
tank or add petrol while the engine is running or
when the engine is hot. If petrol is spilled, do not
attempt to start the engine, but move the
machine away from the area of spillage and
avoid creating any source of ignition until petrol
vapours have dissipated. Replace all fuel tank
and container caps securely.
4. Replace faulty silencers or other parts.
5. Before using, always visually inspect to see that
the trimmer head, blade, and bolts are not worn
or damaged. Replace worn or damaged parts.
Operation and Caution
1. Do not operate the engine in a confined space
where dangerous carbon monoxide fumes can
collect, refuel outdoors only.
2. Always wear protective equipment, including
footwear, gloves eye and ear protection.
Appropriate clothing that provides some
protection whilst operating the brushcutter. Never
wear clothing that become entangled.
3. Operate only in daylight or in good artificial light.
4. Avoid operating the equipment in wet grass,
where feasible.
5. Always be sure of your footing on slopes.
6. Walk, never run, always be in control of the
machinery.
7. Exercise extreme caution when changing
direction on slopes.
8. Do not work on excessively steep slopes of more
than 20°
9. Never operate the trimmer with defective guards,
or without safety devices in place.
10. Do not change the engine governor settings
or over speed the engine.
11. Keep your feet well away from the blade when
starting the engine and in accordance with the
instructions.
12. Always ensure the engine is fully switched off
before carrying the trimmer.
Stop the engine and disconnect the spark plug
wire, make sure that all moving parts have come
to a complete stop and make sure engine has
had time to cool.

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- Before checking, cleaning or working on the
trimmer.
- After striking a foreign object. Inspect for
damage and make repairs before restarting.
- Stop the engine and disconnect the spark
plug wire, make sure that all moving parts
have come to a complete stop and make sure
engine is completely cooled. Whenever you
leave the trimmer and before refuelling.
1. Keep all nuts, bolts and screws tight to be sure
the equipment is in safe working condition.
2. Never store the equipment with petrol in the tank
inside a building where fuel vapours can reach an
open flame or spark or where the temperature is
high.
3. Before storage allow the engine to cool.
4. To reduce the fire hazard, keep the engine,
silencer and petrol storage area free of grass,
leaves, or excessive grease.
5. Check the guards frequently for wear or
deterioration.
6. Replace worn or damaged parts for safety.
Genuine parts should always be used as parts of
inferior quality can damage the equipment and
compromise safety.
7. If the fuel tank has to be drained, this should be
done outdoors. Always ensure engine is
completely cooled before starting this task.
8. If the blade needs to be removed, wear strong
gloves to prevent injury to hands and fingers.
9. Never crank the engine when the spark plug is
removed.
10. Frequently check the fuel lines and fittings for
damage and cracks, replace if necessary
11. Never start the engine with the air filter cover
removed.
12. Carefully clean the trimmer after use to remove
debris as this can damage and corrode.
Warning: Do not touch the rotating blade
or trimmer line.
Warning: Refuel in a well-ventilated area
with the engine stopped.
2. Parts
Descriptions
KB models
K models
1. Engine 8. Handle bracket 15.Bracket for harness
2. Clutch housing 9. Handle handwheel bolt 16.Recoil starter handle
3. Throttle cable tube 10.Drive shaft 17.Fuel cap
4. Handle assembly 11.Guard bracket 18.Choke lever
5. Handle grip 12.Gauard
6. Throttle lever control 13.Gear case
7. Engine switch 14.Nylon line cutting assy

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Engine Parts Descriptions
Engine Warning Labels
A: The Owner’s manual contains important information on safe
operation. Read it before operating engine.
B: Exhaust gas contains carbon monoxide, an odourless and
deadly poison. Do not run Engine in an enclosed area.
C: Gasoline is extremely flammable and explosive. No open flames
or other source of ignition.
D: Engines can become extremely hot during normal operation.
Keep away from hot parts of the engine.
3. Assembly Instructions
Installation of the Loop Type Handle (KB models)
1. The ‘L’ shaped half of the loop handle locates as
shown opposite fitting onto the rubber mount on the
shaft.
The indentation on the rubber mount helps to
ensure the correct location.
2. The main loop handle plastic grip section fits
over the rubber mount and the ‘L’ shaped part fitted
before.
Fit the 4 bolts, tightening them with an allen key.
Ensure the handle is secured correctly.

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Assembly Instructions
Installation of the Bike Type Handle (K models)
1. Remove the handwheel bolt that locks the upper
clamshell bracket in place.
2. The clamshell bracket is ready to locate the bike
handle tube across the rubber mounting as shown.
3. With the bike handle tube fitted, latch the top
clamshell bracket as shown.
Hinge the bracket over the tube.
4. Adjust the bike handle position to suit the
operator and tighten the handwheel to clamp in
place.

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Installation of the Guard
1. Fit the rubber sheet around the brushcutter shaft
as shown opposite, near to the top of gearbox
casing.
2. Attach the guard metal bracket with the single
bolt to the shaft.
Position the plastic guard between the metal
bracket and the shaft as shown opposite.
3. Place the plastic top plate over the shaft such
that the holes align with the plastic guard and metal
bracket.
Insert and tighten the 4 bolts with an allen key. The
bolt should be fixed to the metal bracket.
Check that the guard is fixed correctly.
Fitting of the Nylon Line or Grass Mowing Head
Warning: Always ensure the engine is switched off before completing any maintenance.
1. The brushcutter shaft, before fitting the thrust plate. 2. Fit the thrust plate as shown above.

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3. Fit the nylon line grass mowing head by
screwing the part onto the shaft. Rotate counter-
clockwise.
Block the shaft from rotating as shown below.
4. Insert the blocking rod in the top of the gearbox
as shown opposite, rotating until the shaft is
blocked or locked.
This allows the head to be tightened or loosened
without the shaft rotating.
Fitting of the Metal Cutting Blade
Warning: Always ensure the engine is switched off before completing any maintenance.
1. Remove the nylon line head by reversing the
installation instructions above.
It is essential that the metal blade is checked for
signs of damage or wear. Replace as necessary.
2. Fit the thrust plate as shown opposite. Ensure
the plate fits properly on the spindle.

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Fitting of the Metal Cutting Blade continued
3. Wear protect gloves when fitting metal blade. 4.Fit the blade holder as shown
5. Place the larger disc or holder over the brass
holder. Counter-clockwise tighten the nut.
Insert the blocking rod to stop the shaft from
rotating to allow the nut to be tightened.
When ready to use remove the metal blade covers.
Re-fit after use to prevent injury.
Nylon Line Head Assembly & Line Fitting
The nylon line head has a bump feed system.
Whilst operating the nylon line is fed by bumping
the head of the line holder.
To add nylon line, first switch off the engine:
Release the top cover (1) of the head by squeezing
the two tabs inwards and extract the cover. With a
maximum of 6m of nylon line, fold the length and
catch the centre point using the spool catch.
Wind each half length on each divider until
approximately 10cm of line is left. Feed the line
through the eyelets (6)
Refit the top cover (1)

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4. Fuel and Oil Recommendations
Warning:
Petrol is extremely flammable and can be
explosive under certain conditions, creating the
potential for serious burns.
Turn the ignition switch to “OFF”.
Do not smoke. Make sure the area is well-ventilated
and free from any source of flame or sparks; this
includes any appliance with a pilot light.
Never fill the tank completely to the top. If the tank is
filled completely to the top, heat may cause the fuel
to expand and overflow through the vents in the tank
cap.
After refuelling, make sure the tank cap is closed
securely. If petrol is spilled on the fuel tank, wipe it
off immediately.
Note: Running on petrol only will cause the
engine to seize. Use petrol-oil mixture.
Use petrol and engine oil mixing ratio: 50:1
(Petrol 50, 2-stroke engine Oil 1)
Note: Do not use any fuel that contains
more ethanol or other oxygenates than
specified for E10 fuel* in this engine.
Damage to the engine and fuel system, or engine
starting and/or performance problems may result
from the use of improper fuel.
*E10 means fuel containing up to 10% ethanol as
specified by European directive.
Fuel Type and Octane Rating
Use clean, fresh unleaded petrol with ethanol
volume content not more than 10% and an octane
rating equal to or higher than that shown in the table.
Ethanol Content: E10 or less
Minimum Octane Rating: RON 91
- Do not use petrol that has been stored longer than
two months.
- To ensure proper starting at low ambient
temperatures, fresh winter grade fuel must be used.
- If “knocking or pinging” occurs, use a different
brand of petrol or higher octane rating.
Recommended engine oil:
High quality 2-stroke engine oil
JASO Service Classif cation - FC class
Fuel Petrol and Oil Mix:
Pour the 2-stroke engine oil and the petrol into an
appropriate container with the ratio shown above,
and shake it thoroughly to avoid the separation of
them.
Ensure the engine and tank are level. Then pour it
into the fuel tank with a suitable funnel to avoid spills.
5. Adjustment of Throttle Cable
When setting the engine to equipment’s (bush
cutter. Etc.), adjust the throttle cable in the following
procedures:
1. Remove the air cleaner cap. Loosen the lock nut.
2. Turn the adjusting screw. Be sure that the idle
screw touches throttle plate at the swivel and the
play of the throttle cable is around 2 mm.
3. Squeeze the throttle lever. Be sure that throttle
plate touches the stopper.
4. Tighten the lock nut.
2
Stroke engine oil
2
.5
mL
Gasoline
1000
mL
Container mixing fuel (Example)

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6. Starting Procedure
Warning:
Never fill the tank so the fuel level rises into the filler
neck. If the tank is overfilled, heat may cause the fuel
to expand and overflow through the vents in the tank
cap. After refuelling, make sure the fuel tank cap is
closed securely.
If petrol is spilled on the fuel tank, wipe it off
immediately.
DANGER
Exhaust gases contain carbon monoxide, a
colourless, odourless, poisonous gas. Do not
operate the engine in enclosed areas. Provide
adequate ventilation at all time.
- Open the fuel tank cap and fill the fuel tank with
50 : 1 petrol/oil pre-mixed fuel.
- Pour slowly to avoid “spill back” and allow air to
escape from the fuel tank.
- Close the tank cap securely by turning it clockwise
as far as it will go.
Starting:
1. Turn the engine switch on the engine or the
equipment to the “I” (starting) position.
2. Move the throttle lever on the equipment to the
fully CLOSED (engine idle speed) position.
3. Slowly push the priming pump several times until
the fuel comes out of the overflow tube.
Note:
This engine is designed so that overflowed fuel due
to pushing a priming pump is to be returned to the
fuel tank. There is no fear of flooding the engine, so
push the priming pump enough times to get the
engine started.
Above: Fuel priming
4. Turn the choke lever clockwise to switch to the
“STARTING” position.
Note:
If the throttle lever is squeezed or locked at half
position, the engine won’t start. Be sure the throttle
lever is in the fully CLOSED position.
Also, please note:
When the engine is already warm up, no lift up lever
or choke lever required.
5. Pull the recoil starter grip slowly to engage the
starter, then give a short, quick pull.
Throttle lever
Engine switch

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Starting continued:
Warning:
Releasing the starting rope suddenly may allow the
rope to whip around and cause injury and/or
damage the recoil starting mechanism. When
starting the engine, firmly grasp the recoil starter
grip; do not grasp the starter rope itself.
Always control the rope as it rewinds into the
housing.
6. Squeeze the throttle lever to switch the lift up lever
to the “RUNNING” (engine idle speed) position, and
then release the throttle lever back to fully
“CLOSED” (engine idle speed)
Note:
Should the engine fail to start, do not try the
recoil start many times with the lift up lever to
the “STARTING” position or the choke lever to
the “CLOSED” position.
This will cause the fuel to flood into the cylinder and
make starting even more difficult. In this case, set
the lift up lever to the “RUNNING” position or the
choke lever to the “OPEN” position. And then, repeat
the starting.
After starting, vary the engine speed a few times, by
operating the throttle lever to draw out the remaining
air in the carburettor.
Note:
Allow sufficient warm-up time to prevent engine
damage and run the engine smoothly.
The engine should be run at idle speed for a few
minutes to allow it to warm up before applying a
load. This will allow oil to reach engine parts, and
allow piston clearance to reach design
specifications.
7. Warming Up Procedure
After starting the engine, run the engine at the idling
speed (throttle lever position is fully CLOSED) for a
few minutes.
Fuel Adjustment
The carburettor has been adjusted to the optimum
fuel supply at the factory. Don’t reset the carburettor
setting.
(Note: if adjustment is needed, it should be
performed by an authorised dealer)
Idle Speed Adjustment:
If the engine does not run the idle speed, it may be
set too low, turn the idle screw clockwise to increase
the engine idle speed.
If the cutting head moves when the engine is running
at the idle speed, turn the idle screw counter-
clockwise to decrease the engine idle speed.
Refer to the engine manual for further details.

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Throttle lever
Engine switch
8. Stopping
Move the throttle lever on the equipment to the fully
CLOSED (engine idle speed) position, and the
engine running at idle speed.
Turn the engine switch to the “O” (stopping) position.
Note:
Suddenly stopping engine from highspeed
operation can cause engine damage.
Reduce engine speed to idle speed for one minute
before shutting engine off after high-speed, full-load
operation.
Emergency Stop:
Turn the engine switch to the “O” (stopping) position.
Note:
-Never stop the engine by closing the choke lever.
-Never stop the engine during operation while
running above idle speed.
-Shut off the engine and allow it to cool before
transporting or storing the unit.
-Do not put the unit on dry grass or near any
flammable object unless the engine is cold or cooled
down.
9. Maintenance
Air Cleaner Service
Clean the air cleaner element every 20 hours.
-Remove the air cleaner cap from the air cleaner
case by removing the air cleaner cap screw.
-Remove the element from the air cleaner case.
-Wash the element in detergent and water and dry it
thoroughly.
-Reinstall the element in the air cleaner case and
reinstall the air cleaner and tighten the screw.
Note:
Improper element cleaning can result in engine
damage.
Do not use compressed air to clean or dry element.
Always clean element with an approved high flash
point solvent only. Never use petrol.
Do not operate engine with air filter parts removed.
Fuel Tank Cap Service
A breather passage is incorporated in the tank cap.
If the breather passage is clogged, the fuel will not
flow into the carburettor, causing problems with
starting or running the engine.
At the same time, make sure that the base of the
breather assembly is fitted firmly into the groove
inside the tank cap as shown.
Breather
passage
Tank cap
Fuel tank
Breather
assembly

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Maintenance continued:
Fuel Filter Service
Every 20 hours of operation
-Pull the fuel filter out from the fuel tank.
-Clean the fuel filter in a bath of high flashpoint
solvent.
-Dry the fuel filter and reinstall it into the fuel tank.
Note: If a fuel still does not flow well after the
cleaning, replace the fuel filter with new one.
Warning:
Many solvents are highly flammable and may cause
serious burns. Improper use of solvents can result in
fi re or an explosion. Do not use petrol or low flash-
point solvents to clean the fuel filter. Clean only in a
well-ventilated area away from sources of sparks or
flame, including any appliances with a pilot light.
Spark Plug Service
Every 50 hours of operation
-Take the spark plug cap with fingers and pull it up.
-Remove the spark plug by using a suitable plug
wrench.
-Clean the electrodes by scraping or with a wire
brush to remove carbon deposits and wetness.
-Inspect for cracked porcelain or other wear and
damage. Replace the spark plug with a new one if
necessary.
Spark Plug Maintenance continued
-Check the spark plug gap and reset it if necessary.
The gap must be between 0.6 and 0.7mm. To
change the gap, bend only side-electrode, using a
spark plug tool.
-Install and tighten the spark plug to 14N·m
(1.4kgf·m).
-Fit the spark plug cap on the spark plug securely.
-Pull up the spark plug cap lightly to make sure of
the installation of the spark plug cap.
Recommended spark plug:
NGK BPMR7A
Spark Arrester Service
Every 50 hours of operation
-Remove the spark arrester from the exhaust hole of
muffler
-Clean deposits from the spark arrester screen by
brushing it.
-Install the spark arrester.
Carbon Removal of Engine Internal Parts
Every 50 hours of operation These items must be
performed with proper tools.
See your authorised dealer for service.
Warning:
Petrol is a toxic substance. Dispose of petrol
properly.
Contact your local authorities for approved disposal
methods.
Fuel Filter
Electrodes
Spark plug gap
Spark arrester
Muffler

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10. Storage
Engine to be stored over 30 days should be
completely drained of fuel to prevent gum deposits
forming on essential carburettor parts fuel filter and
fuel tank.
-Clean the engine and the brushcutter.
-Remove all the fuel from the tank and run the
engine at idling to use up the fuel in the carburettor.
-Remove the spark plug, pour in 0.5 ml of new 2-
stroke engine oil through the plug hole, pull the recoil
starter grip several times, and reinstall the spark
plug.
-Slowly pull the recoil starter grip until resistance is
felt.
-Store the engine in a clean and dry place.
11. Troubleshooting Guide
For an authorised repairer see the Cobra dealer locator – cobragarden.co.uk
Symptom
Probable cause
Remedy
Engine won't
start or output
is low
Insufficient
compression
Faulty piston, cylinder and piston ring
See an authorised repairer
Loose spark plug
Tighten properly.
Loose cylinder bolts
No fuel to
combustion
chamber
No fuel in fuel tank
Fill fuel tank.
Blocked fuel filter or tube
Clean.
Blocked air vent in tank cap
Faulty carburettor
See an authorised repairer
Spark plug
fouled by fuel
Over-rich fuel/air mixture
Turn lift up lever to "Starting"
position. Rotate engine with
spark plug removed to
discharge excess fuel.
Clean the spark plug.
Clogged air cleaner
Clean
Faulty carburettor
See an authorised repairer
Incorrect grade/type of fuel
Change petrol.
Water in fuel
Replace spark plug.
Faulty spark plug
No spark or
weak spark
Faulty ignition coil
See an authorised repairer
Engine switch left in "O"(STOP)
position
Turn the engine switch to
"START" position.
Clogged air cleaner
Clean
Low output
Engine
overheats
Recoil starter or cooling air path
clogged with dirt
See an authorised repairer
Carbon built--up in combustion
chamber
Poor ventilation around engine
Select a better location.
Lubricator
Plug hole

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12. Warranty
This product is warranted in accordance with legal regulations for a 24 month period when used non-
commercially and 12 months when used commercially, this is effective from the date of purchase by the
first user.
This warranty covers all material or production failures, it does not include: defects from normal wear and
tear, parts such as, bearings, brushes, cables, air cleaning elements, brake pad, clutch disc, tyre, wheel,
recoil starter rope, belts, cutter blades, plugs, lubricant oils and grease or accessories. Damage or defects
resulting from abuse, accidents or alterations, natural fading of painted or plated surfaces, sheet peeling
and other natural deterioration.
Any damage that occurs from the use of non-genuine Cobra parts will not be covered.
We reserve the right to reject any claim where the purchase cannot be verified or when it is clear that the
product was not maintained properly. (Clean ventilation slots, carbon brushes and serviced regularly)
Expenses incidental to the warranty claim that are not covered;
-Compensation for loss of time, commercial loss or rental costs of substitute product.
-Costs incurred for transportation to and from the dealership.
Any damage that occurs from the following will not be covered; exposure of the product to smoke and soot,
chemical agents, bird droppings or other animal waste, seawater, sea breeze, salt or other environmental
phenomena.
Any damage resulting from operating methods other than those indicated in the owner’s manual will not be
covered.
Your purchase receipt must be kept as proof for date of purchase. Your un-dismantled machinery must be
returned to your dealer in an acceptably clean state, accompanied by your proof of purchase.
Please Register Your Cobra
If your dealer did not collect registration information from you, please take a few minutes and register your
purchase with Cobra.
You can register by completing and mailing the registration card that should be in the box or by going online
to: www.cobragarden.co.uk and clicking on Product Registration.
Before using the machinery, all operators must read this manual
13. Environment
Should your machine need replacement after extended use, do not put it in the domestic waste but dispose
of it in an environmentally safe way.

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14. EC-DECLARATION OF CONFORMITY
EC Declaration of Conformity
We herewith declare,
Cobra Garden Machinery
Henton & Chattell Ltd, London Road, Nottingham NG2 3HW United Kingdom
that the following machine complies with the appropriate basic safety and health requirements of the EC Directive based on
its design and type, as brought into circulation by us.
In case of alteration of the machine, not agreed upon by us, this declaration will lose its validity
Machine Description:
Brush cutter
Machine Type:
BC270KB (PNBC270K) BC270K (PNBC270K) BC350KB (PNBC350KB) BC350K
(PNBC350K) BC450K (PNBC450K)
Displacement
BC270 -26.3 cm3BC350 - 34.4 cm3BC45K -45.4 cm3
Measured sound power level:
95 dB(A)
Guaranteed sound power level:
110 dB(A)
Name of Notified Body
Intertek Testing Services Ltd.,
Building No 86
1198 Qinzhou Road North
Shanghai, 200233
Applicable EC Directives
EC Machinery Directive:2006/42/EC
EC Directive of Electromagnetic Compatibility:2004/108/EC
EC Directive of noise emission: 2005/88/EC
Applicable Harmonized Standards
EN ISO 11806
EN ISO 14982
Authorized Signature/Date
Peter J. Chaloner 18th April 2018
Title of Signatory
Managing Director
Name and address of the person
authorised to compile the technical
file
Cobra Garden Machinery
Henton & Chattell Ltd, London Road, Nottingham NG2 3HW United Kingdom