Cobra SG15L User manual

MODEL: SG15L (DR-SG-15)
COBRA PETROL
STUMP GRINDER
OWNER’S MANUAL
IMPORTANT
Read safety rules and instructions carefully before operating equipment.
Cobra Garden Machinery
Henton and Chattell Ltd., London Road, Nottingham NG2 3HW UK
www.cobragarden.co.uk

1
Table of Contents
PART I: General Safety Rules ....................................................................................... 03
PART II: Familiar with the Stump Grinder....................................................................... 07
PART III: Install the Stump Grinder................................................................................. 08
PART IV: Operating the Stump Grinder.......................................................................... 11
PART V: Maintaining the Stump Grinder.........................................................................15
PART VI: Troubleshooting and Parts List........................................................................16
Conventions used in this manual
WARNING
This indicates a hazardous situation, which, if not avoided, could result in
death or serious injury.
CAUTION
This indicates a hazardous situation, which, if not avoided, could result in
minor or moderate injury.
NOTICE
This information is important in proper using of your machine. Failure to follow
this instruction could result in damage to your machine or property.
Additional Information and Potential Changes
We reserve the right to discontinue, change, and improve its products at any
time without notice or obligation to the purchaser. The descriptions and
specifications contained in this manual were in effect at printing. Equipment
described within this manual may be optional. Some illustrations may not be
applicable to your machine.

WARNING
Readthis Safety& Operating Instructionsmanual before you usethe Stump Grinder. Become familiar with
the operation and service recommendations to ensure the best performance of yourmachine.
Propose
CAUTION
This machine is designed solely to grind stumps and must not be used for any other purpose.
It should only be used bytrained operators who are familiar with the content of this manual.It is
potentiallyhazardousto fit or useany partsotherthanyourdealerparts.Thecompanydisclaimsall
liability forthe consequences of such use, which in addition voids the machine warranty.
Before using the stump grinder
NOTICE
A. Operators must be fully trained before using this machine.
B. UserManualis readandunderstood.
C. Machine is positioned on level ground, all guards are fitted and in good condition.
D. Teeth are in good condition and secure.
E. All fasteners are checked for tightness.
F. Only stumps are removed with this machine.
G. Emergency stop wire is correctly connected and the switch is functional.
H. Fire extinguisher is available on site.
When using the stump grinder
NOTICE
A. Always stay clear of the rotating cutter wheel.
B. It is better to have a second trained operator within easy reach of the machine.
C. Always maintain strict discipline and service machine at specified periods.
D. DO NOT grind stumps with tow bar installed where supplied.
E. DO NOT put any part of your body near the cutter while the machine is running.
F. DO NOT operate the machine while under the influence of alcohol or drugs.
G. DO NOT operate inside a building or confined space.

WARNING
Protecting Yourself and Those Around You
WARNING
This is a powerful machine, with moving parts operating with high energy. You must operate the
machine safely. Unsafe operation can create a number of hazards for you, as well as anyone else in the
nearby area. Always take the following precautions when using this machine:
A. Keep in mind that the operator or user is responsible for accidents or hazards occurring to other
people,their property, and themselves.
B. Always wear protective goggles or safety glasses with side shields while using the Stump Grinder to
protect your eyes from possible thrown debris.
C. Avoid wearing loose clothing or jewellery, which can catch on moving parts.
D. We recommend wearing gloves while using the Stump Grinder. Be sure your gloves fit properly and
do not have loosecuffs or drawstrings.
E. Wear shoes with non-slip treads when using your Stump Grinder. Safety shoes are recommended
to wear. Do not use the machine with inadequateprotectiveeye, clothing andfootwear.
F. Wear long trousers while operating the Stump Grinder.
G. Keep bystanders at least 15m away from your work area at all times. Stop the engine when another
personor pet approaches.
Safety for Children and Pets
WARNING
Tragic accidents can occur if the operator is not alert to the presence of children and pets. Children are often
attracted to the machine and the chipping activity. Never assume that children will remain where you last
sawthem. Always followtheseprecautions:
A. Keep children and pets at least 15m from the working area and ensure they are under the
watchfulcareof a responsible adult.
B. Be alert and turn the machine off if children or pets enter the work area.
C. Never allow children to operate the stump grinder.
Safetywith Petrol - Powered Machines
Petrol is a highly flammable liquid. Petrol also gives off flammable vapor that can be easily ignited and cause a
fire or explosion. Never overlook the hazards of petrol. Always follow these precautions:
A. Never run the engine in an enclosed area or without proper ventilation as the exhaust from the
engine containscarbonmonoxide, whichis an odorless,tasteless,anda deadlypoisonousgas.
B. Storeallfueland oilin containers specificallydesignedand approved for thispurposeand keep
awayfromheatand openflame,and out of thereachof children.
C. Replace rubber fuel lines and grommets when worn or damaged and after 5 years of use.

WARNING
D. Fill the petrol tank outdoors with the engine off and allow the engine to cool completely. Don't handle
petrol if you or anyone nearby is smoking, or if you're near anything that could cause it to ignite or
explode. Reinstallthefuel tank cap andfuelcontainer cap securely.
E. If you spill petrol, do not attempt to start the engine. Move the machine away from the area of the spill
and avoid creating any source of ignition until the gas vapors have dissipated. Wipe up any spilled fuel to
preventafirehazardandproperlydisposeof the waste.
F. Allow the engine to cool completely before storing in any enclosure. Never store a machine that has
petrol in the tank, or a fuel container, near an open flame or spark such as a water heater, space
heater, clothes dryer or furnace.
G. Never make adjustments or repairs with the engine running. Shut down the engine, disconnect the spark
plug wire, keeping it away from the spark plug to prevent accidental starting, wait 5 minutes before
making adjustments or repairs.
H. Never tamper with the engine’s governor setting. The governor controls the maximum safe
operation speed and protects the engine. Over-speeding the engine is dangerous and will cause
damage to the engine and to the other moving parts of the machine. If required, see your
authorized dealer forengine governor adjustments.
I. Keep combustible substances away from the engine when it is hot.
J. Never cover the machine while the muffler is still hot.
K. Do not operate the engine with the air cleaner or the carburetor air intake cover removed. Removal of
such parts couldcreate afirehazard. Do not use flammable solutions to cleanthe air filter.
L. The muffler and engine become very hot and can cause a severe burn; do not touch.
General Safety
Operating this Stump Grinder safely is necessary to prevent or minimize the risk of death or
serious injury. Unsafe operation can create a number of hazards for you. Always take the
following precautions when operating:
A. Your machine is a powerful tool, use with great care. Exercise extreme caution at all times. The
machine is designed to grind stumps.Do not use itforanyother purpose.
B. Know how to stop the Stump Grinder quickly.
C. Never operate your unit on a slippery, wet, muddy, or icy surface. Exercise caution to avoid
slipping or falling.
D. See manufacturer’s instructions for proper operation and installation of accessories.
E. Never use the machine without ensuring that all guards and shields are in place.
F. Never, under any conditions, remove, bend, cut, fit, weld, or otherwise alter standard parts on the
Stump Grinder. This includes all shields and guards. Modifications to your machine could cause
personal injuries and property damage and will invalidyour warranty.
G. If the machine start to make an unusual noise or vibrate, shut down the engine, disconnect the spark
plug wire, keeping it away from the spark plug to prevent accidental starting, wait 5 minutes for engine to
cool down, then inspect for damage. Vibration is generally a warning of trouble. Check damaged
partsand clean, repairand/orreplaceas necessary.
H. Never tamper with safety devices. Check their proper operation regularly.
I. Before performing any maintenance or inspection procedure, shut down the engine, disconnect

the spark plug wire keeping it away from the spark plug to prevent accidental starting, wait 5 minutes
formachineto cooldown.
J. Never allow people who are unfamiliar with these instructions to use the machine. Allow only
responsible individuals who are familiar with these rules of safe operation to use your machine.
K. Never overload or attempt to chip woods beyond the manufacturer’s recommendation. It could result
in personalinjuryor damageto themachine.
L. Whileusing,don'thurryor take things forgranted.When in doubt about theequipment or your
surroundings stopthemachineandtake timetolookthingsover.
M. Never operate the machine when under the influence of alcohol, drugs, or medication.
N. Use the machine only in daylight.
O. Stay alert for hidden hazards or traffic.
P. Keep all nuts and bolts tight and keep the equipment in good operating condition.
Q. ALLWAYS take the brake off before moving or towing.
A Note to All Users
List of warnings and cautions cannot be all-inclusive. If situations occur that are not covered by this manual, the operator
must apply common sense and operate this Stump Grinder in a safe manner. Contact the dealers for assistance in your
area.

PART II: Familiar with the Stump Grinder
It may be helpful to familiarize yourself with the controls and features of the Stump Grinder. If you have any
question, please contact the dealers in yourarea.
TECHNICAL SPECIFICATIONS
Engine
15hp Four Stroke
Brake
Drum Brake
Belt
2PCS V-Belt
Clutch
Centrifugal Clutch
Blades
9 Blades w Tungsten (3x left,3 x right,3x middle)
Cutting Depth
12inch
Packing Size
1040*780*580mm
Gross Weight
130kgs

PART III:Assemble the Stump Grinder
1. Fitting the wheels and drum brake
Fit the drum brake and wheel assemblies as shown ab ove.
1. Fit the drum brake assembly to the left side axle.
2. Install the brake cable as shown opposite.
Adjust the tension on the cable ensure the brake
operates correctly.
3. Fit the wheel with the drum housing to the left side.
4. Fit the other wheel to the right axle as shown.
5. Secure with the flat washer, spring washer and the nut
on each side.
2. Installation of the lower handrail
Fit the lower handle section with the flat washer,
spring washer and nut as shown opposite.

3. Fit the upper handle
Fit the upper handle section with the ratchet fixing bolt and the handle bar lock lever as shown above.
4. Adjustment of the drum brake cable
1. Install brake cable. Remove front jam nut and insert cable stop into brake lever.
2. Once inserted, pull cable back and insert into cable mount. Thread outer nut back on leaving about 15mm of
thread showing. Using13mm spannertotightenboth jamnuts.
3. Adjustment can be done with the knob on the end of the brake handle. Turing the knob clockwise will
increase tension. Counter-clockwise will release the tension.
4. Always check the brake operates as expected before use.

5. Fitting the rear rubber guard
Fit the rear rubber guard as shown
opposite, using the washer, spring
washer and nut as shown opposite.
6. Apply lubricating grease to the bearings
Lubricate the main bearings as indicated opposite before
each use.
This is essential regularmaintenance.
NOTICE
7. Add engine oil and petrol before starting
The stump grinder is shipped without engine oil in the engine, add oil as explained in the engine
manual.
Always check the engine oil before operating the stump grinder.
Fill the engine fuel tank with fresh petrol. Never use stale or old fuel as this will cause
carburetor issues, such as difficulties starting and correct engine performance.

PART IV: Operating the Stump Grinder
Familiarise yourself with the features of your Stump Grinder before beginning the steps outlined in
this chapter.
WARNING
A. Read and understand all instructions, safety precautions, and/or warnings listed in “PART I:
General Safety Rules” before operating the Stump Grinder. If any doubt or question arises about
the correct or safe method of performing anything found in this manual, please contact the dealer
in your area.
B. When operating the Stump Grinder, make sure you are standing in the safe operating area
(OPERATOR ZONE). You must stay in the safe operating area at all times when the machine is in
motion
(whether extending or retracting). Never place any part of your body into a position that causes an
unsafe operating condition.
C. Before loading and operating the Stump Grinder, always wear protective gear, including safety
goggles, hearing protection, tight-fitting gloves without draw strings or loose cuffs, and steel-toed
shoes.
D.Never use an incorrect or unsafe method of operation.
1. Starting
1. Position your Stump Grinder on flat, dry ground.
2. Put the brake on making sure the brake pin and wheel is engaged and locked.
3. Make sure the fuel shut-off valve is in the “ON” position.
4. Move the choke control lever to the “CHOKE” position (should only be needed if the engine is
cold).
5. Move the throttle control lever to the “MID” position.
6. Adjust your bow handle to the desired position.
7. Depress safety shut off bail on the bow handle.
8. Raise the cutter teeth off the ground and start the engine. This is a direct drive unit and the cutter
wheel will rotate during starting.
9. Recoil Start: Turn the Ignition Switch to the “On” position. Grasp the recoil starter handle and
slowly pull until you feel resistance. Let the cord retract a little bit then pull the cord rapidly to start
the engine. One or two pulls usually starts the engine.
10. Move the choke control lever (if used for cold engine) slowly back to the “RUN” position when the
engine is running well.
11. Increase engine speed to FULL SPEED RPM.
2. Stopping
Always test the stopping procedure before operating the stump grinder.
Never leave the stump grinder unattended with the engine running.
1. Let go of the bail shut off on the bow handle
OR
2. Recoil Start: Slide the throttle lever to the LEFT to shut engine off.

3. Operator Zone
The operator should remain behind the Stump Grinder when working.
Keep all others a safe distance of at least 15m from the machine.
WARNING
Clear the area around the stump. Remove all rocks, stones and potential debris from the
working area.
WARNING
Do not place your feet and hands into the cutting wheel area. This is a very UNSAFE and could result
in injury or death. Never allow yourself or others to reach or step to the side or the front of the Stump
Grinder when it is running. This is a very UNSAFE method which could cause personal injury or even
death.
Vibration
If the unit starts to vibrate abnormally shut the unit down. Inspect for missing or broken teeth and
replace if required. Check your teeth bolts that are tight. Check your drive belts.

1. Removing Stumps
1. Remove all loose pieces of wood, stones, wire and other debris from the area before beginning
stump removal.
2. Wind direction should be considered, as it influences the direction in which dust and wood chips
are directed.
3. Never operate the stump grinder after dark. There will not be adequate light to operate the stump
grinder safely.
4. Always allow a cold engine to warm up
before cutting a stump.
5. Only the portion of cutting wheel within
the 80 degree area shown below should
engage the stump. Never undercut the
stump or use the bottom of the cutting
wheel for cutting purposes.
2. Prepare the Grinder at the
Stump
Place the stump grinder into
position with the cutting wheel
near the top edge of the stump.
Engage the brake.
5. Removing Roots
1. Make sure the throttle is set
to FAST. The cutter wheel will
accelerate to cutting speed.
2. Swing the cutting wheel to
one side, then lower it into the
nearest roots that are buried at
the foot of the stump.
3. Swing the cutting wheel before
each sweep, until the roots are
sufficiently removed
4. Raise the cutting wheel until the centre of the cutting wheel is just above the top of the stump.
5. Allow the cutting wheel to stop, release the brake and reposition the machine.
6. Lock the brake again.

6.Cutting the Full Stump
1. Make sure the throttle is set to FAST.
The cutter wheel will accelerate to cutting
speed.
2. Direct the cutting wheel against the
stump, beginning with the nearest top
corner of the stump.
3. Steadily sweep it across the stump left
and right, cutting away 1/2 inch of wood
with each sweep.
4. Raise and lower the cutting wheel
between sweeps by lowering and raising
the control handle.
5. Roll the machine forward and back by pushing and pulling on the control handle. Re-lock it when
the machine has been repositioned and continue cutting.
7.Continue with Final Root Removal
Cut the remaining roots until all roots are removed.

PART V: Maintaining the Stump Grinder
Regular maintenance is the way to ensure the best performance and long life of your machine.
Please refer to this manual and the engine manufacturer's user manual for maintenance procedures.
WARNING
Before performing any maintenance procedure or inspection, stop the engine, wait five
minutes to allow all parts to cool. Disconnect the spark plug wire, keeping it away from the
spark plug.
1. Regular Maintenance Checklist
Procedure
Before Each Use
Every 3
Hours
Every 25
Hours
Every
100
Hours
Check engine oil level
Δ
Check general equipment condition
Δ
Check teeth and bolts
Δ
Check belts
Δ
Check tirepressure
Δ
Clean engineexteriorand cooling
Δ
Change Engine Oil
First time5 hours
Δ
Replace air filter
Δ
Replace spark plug
Δ
2. Engine Service
Refer to the engine manufacturer’s user manual for engine maintenance.
3. Lubrication of bearings
NOTICE
Grease points are installed. Grease the main cutting axle bearing before each use.
4. Transportation
The stump grinder is designed to be transported via a van or small trailer. The machine is equipped with
grab bars that are to be used for both lifting the machine, and strapping it down. This machine weighs
approximately 110kg and should only be lifted using correct apparatus or an adequate number of
people working as a team. Ensure fuel and oil caps are secure and cannot leak.

PART VI: Troubleshooting Guide
WARNING
Before performing any maintenance procedure or inspection, stop the engine, wait five
minutes to allow all parts to cool. Disconnect the spark plug wire, keeping it away from the
spark plug.
Symptom
Possible Cause
The engine won’t start.
(Please refer to the engine user
manual for engine-specific
procedures.)
Check the SAFETY BAR HELD DOWN to engage the
safety cut-off switch. Check the fuel shut-off valve is ON
Always use fresh, clean petrol. If the petrol is old, change
it. Use a fuel stabilizer if you keep petrol longer than 30
days.
Check the spark plug is clean. If the spark plug is dirty or
cracked, change it. If it’s oily, leave it out, hold a rag over
the plug hole and pull the recoil cord several times to blow
out any oil in the cylinder, then wipe off the plug and
reinsert it.
The engine lacks power or is not
running smoothly.
(Please refer to the engine user
manual for engine-specific
procedures.)
Check that the Throttle Lever is in the “FAST” position.
TURN OFF THE CHOKE
Check the air filter is clean. If it’s dirty, change it following
the procedure in the engine manufacturer’s owner’s
manual.
Is the spark plug clean? If it’s fouled or cracked, change it.
If it’s oily, leave it out, hold a rag over the plug hole and
pull your recoil cord several times to blow out any oil in the
cylinder, then wipe off the plug and reinsert it.
Are you using fresh, clean unleaded petrol? If it’s old,
change it. Use a fuel stabilizer if you keep petrol longer
than 30 days.
Does your engine have the right amount of clean oil? If it’s
dirty, change it following the procedure in the engine
manufacturer’s owner’s manual.
Check the oil level and adjust as needed.
Engine smokes.
(Please refer to the engine user
manual for engine-specific
procedures.)
Check the oil level and adjust as needed.
Check the air filter and clean or replace if needed.
You may be using the wrong oil—too light for the
temperature. Refer to your Engine Owner’s Manual for
detailed information.
Clean the cooling fins if they’re dirty.
Machine does not seem to have full
grinding power.
The belts may be too loose and slipping. Adjust or replace
belts as needed.
The teeth may be dull or broken, replace.

Run engine at full RPM when grinding.

Environmentally Friendly Disposal
According to EU directive 2012/19/EU on electric and electronic equipment and its
implementation into national law, all electric tools must be separately collected and
environmentally friendly recycled. Alternative disposal: If the owner of the power tool
does not return the tool to the manufacturer, he is responsible for proper disposal at a
designated collection point that prepares the device for recycling according to national
recycling laws and regulations. This does not include accessories and tools without
electric or electronic components.
Warranty
This product is warranted in accordance with legal regulations for a 24 month period effective from
the date of purchase by the first user.
This product will not be covered if used in a commercial application.
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 stump grinder
must be returned to your dealer in an acceptably clean state, accompanied by your proof of purchase.
Please Register Your Stump Grinder
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.

EC-Declaration of Conformity
EC Declaration of Conformity
We herewith declare,
Cobra Garden Machinery
Henton & Chattell Ltd, London Road, Nottingham NG2 3HW UK
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
Product
Petrol Powered Stump Grinder
Machine Type:
SG15L (DR-SG-15)
Rated power
420cm3 9kW/3600min-1
Measured sound power level:
92.39dB(A)
Guaranted sound power level:
110dB(A)
TÜV SÜD (China) Shanghai,
No.151 Heng Tong Road, Shanghai 200 070, PRC
Applicable EC Directives:
2006/42/EC
2014/30/EU
2016/1628/EC
2000/14/EC
Applicable Harmonized
Standards:
EN ISO 12100:2010, BS
EN ISO 14120:2015
EN13683:2003+A2:2011+AC:2015
EN ISO 14982:2009
Authorized Signature/Date:
8/1/2023
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 UK