Save This Manual Keep this manual for the safety warnings and precautions, assembly,
operating, inspection, maintenance and cleaning procedures. Write the product’s serial number in the
back of the manual near the assembly diagram (or month and year of purchase if product has no number).
Keep this manual and the receipt in a safe and dry place for future reference.
WARNING!
IMPORTANT INFORMATION
The Hitch Coupler MUST be properly secured to the hitch ball of
the towing vehicle. After assembly and attachment, pull up and down
on the Hitch Coupler to make sure the hitch ball is fitting snugly in the
Hitch Coupler. There must be no play between the hitch ball and Hitch Coupler. If there is play, tighten the Adjustment Nut until no play
is present. If the Adjustment Nut is too tight, the Handle will not lock.
Carefully read and follow the complete instructions in this manual
BEFORE setup or use.
If the Coupler is not secured properly, the ball could
come loose while the Trencher is in motion, possibly
causing property damage, SERIOUS PERSONAL INJURY,
or DEATH.
Intake0.15 ± 0.02 mm
Exhaust0.20 ± 0.02 mm
Idle1,740± 50 RPM
Maximum3,600 RPM
10W-30 above 32° F
5W-30 at 32° F or below
3 hours
Counterclockwise
The emissions control system for this Engine is warranted for standards set by the
U.S. Environmental Protection Agency and by the California Air Resources Board (also known as CARB).
For warranty information, refer to the last pages of this manual.
This is the safety alert symbol. It is used to alert you to potential
personal injury hazards. Obey all safety messages that
follow this symbol to avoid possible injury or death.
Indicates a hazardous situation which, if not avoided,
will result in death or serious injury.
Indicates a hazardous situation which, if not avoided,
could result in death or serious injury.
Indicates a hazardous situation which, if not avoided,
could result in minor or moderate injury.
Addresses practices not related to personal injury.
SAFETYSETUPOPERATIONMAINTENANCE
SymbolProperty or Statement
RPM
HP
Revolutions Per Minute
Horsepower
WARNING marking concerning
Risk of Eye Injury. Wear ANSI-approved
safety goggles with side shields.
Read the manual before
set-up and/or use.
WARNING marking concerning
Risk of Hearing Loss.
Wear hearing protection.
SymbolProperty or Statement
WARNING marking concerning
Risk of Respiratory Injury.
Operate engine OUTSIDE and far away
from windows, doors, and vents.
WARNING marking concerning
Risk of Fire while handling fuel.
Do not smoke while handling fuel.
WARNING marking concerning
Risk of Fire.
Do not refuel while operating.
Keep flammable objects
away from engine.
IMPORTANT SAFETY INSTRUCTIONS
WARNING! Read all instructions.
Failure to follow all instructions listed below may result in fire, serious injury and/or DEATH.
The warnings and precautions discussed in this manual cannot cover all possible conditions and
situations that may occur. It must be understood by the operator that common sense and caution
are factors which cannot be built into this product, but must be supplied by the operator.
SAVE THESE INSTRUCTIONS
Set up Precautions
1. Gasoline fuel and fumes are flammable, and
potentially explosive. Use proper fuel storage
and handling procedures. Do not store fuel
or other flammable materials nearby.
2. Have multiple ABC class fire extinguishers nearby.
3. This equipment has a spark arresting muffler
included. A spark arresting muffler is required
by law in California, on some US Forest Service
land, and possibly in other areas or situations.
4. Set up and use only on a flat, level,
well-ventilated surface.
5. Wear ANSI-approved safety goggles, heavy-duty
work gloves, and dust mask/respirator during set up.
6. Use only lubricants and fuel recommended
in the Specifications chart of this manual.
NEVER use inside a home or garage,
EVEN IF doors and windows are open.
Only use OUTSIDE and far away from windows,
doors, and vents.
2. Contact local utility companies before
beginning any project. Buried utility lines
may not be marked and, if struck, can cause
SERIOUS PERSONAL INJURY or DEATH.
3. Keep children away from the equipment,
especially while it is operating.
4. Keep all spectators at least 20 feet from
the equipment during operation.
5. Fire Hazard! Do not fill fuel tank while engine is
running. Do not operate if gasoline has been spilled.
Clean spilled gasoline before starting engine.
Do not operate near pilot light or open flame.
6. Do not touch engine during use.
Let engine cool down after use.
7. Never store fuel or other flammable
materials near the engine.
8. Industrial applications must follow
OSHA requirements.
9. Do not leave the equipment unattended when it is
running. Turn off the equipment (and remove safety
keys, if available) before leaving the work area.
10. The equipment can produce high noise levels.
Prolonged exposure to noise levels
above 85 dBA is hazardous to hearing.
Wear ear protection when operating the equipment
or when working nearby while it is operating.
11. Wear ANSI-approved safety goggles
and hearing protection during use.
12. Do not operate in explosive atmospheres,
such as in the presence of flammable
liquids, gases, or dust. Gasoline-powered
engines may ignite the dust or fumes.
Engine exhaust contains
carbon monoxide. This is a poison
you cannot see or smell.
13. People with pacemakers should consult their
physician(s) before use. Electromagnetic fields in
close proximity to a heart pacemaker could cause
pacemaker interference or pacemaker failure.
Caution is necessary when near the
engine’s magneto or recoil starter.
14. Use only accessories that are recommended
by Harbor Freight Tools for your model.
Accessories that may be suitable for one
piece of equipment may become hazardous
when used on another piece of equipment.
15. Stay alert, watch what you are doing and use
common sense when operating this piece of
equipment. Do not use while tired or under the
influence of drugs, alcohol or medication.
16. Do not overreach. Keep proper footing and
balance at all times. This enables better control
of the equipment in unexpected situations.
17. Use this equipment with both hands only.
Using equipment with only one hand
can easily result in loss of control.
18. Dress properly. Do not wear loose clothing or
jewelry. Keep hair, clothing and gloves away
from moving parts. Loose clothes, jewelry or
long hair can be caught in moving parts.
19. Parts, especially exhaust system components,
get very hot during use. Stay clear of hot parts.
20. Do not cover the engine or
equipment during operation.
21. Keep the equipment, engine, and
surrounding area clean at all times.
22. Use the equipment, accessories, etc., in
accordance with these instructions and in the
manner intended for the particular type of
equipment, taking into account the working
conditions and the work to be performed.
Use of the equipment for operations different from
those intended could result in a hazardous situation.
23. Do not operate the equipment with known
leaks in the engine’s fuel system.
24. WARNING: Some dust created by power sanding,
sawing, grinding, drilling, and other construction
activities, contains chemicals known to the State
of California to cause cancer and birth defects or
other reproductive harm. Some examples of these
chemicals are:
• Lead from lead-based paints
• Crystalline silica from bricks and cement or other
masonry products
• Arsenic and chromium from chemically
treated lumber
Your risk from these exposures varies, depending
on how often you do this type of work. To reduce
your exposure to these chemicals: work in a well
ventilated area, and work with approved safety
equipment, such as those dust masks that are
specially designed to filter out microscopic particles.
(California Health & Safety Code § 25249.5, et seq.)
25. WARNING: This product contains or, when
used, produces a chemical known to the State
of California to cause cancer and birth defects
or other reproductive harm. (California Health
& Safety Code § 25249.5, et seq.)
26. WARNING: This product contains di (2-ethylhexyl)
phthalate (DEHP), a chemical known to the State
of California to cause cancer and birth defects
or other reproductive harm. (California Health
& Safety Code § 25249.5, et seq.)
27. Never place your hands or body near a hydraulic
fluid leak. High-pressure fluid can be forced
under the skin resulting in serious injury.
Transport Precautions
1. Only use a suitable means of transport and
lifting devices with sufficient weight bearing
capacity when transporting the equipment.
2. Properly secure the equipment to transport vehicle
to prevent it from rolling, slipping, and tilting.
28. When spills of fuel or oil occur, they must be
cleaned up immediately. Dispose of fluids and
cleaning materials as per any local, state, or
federal codes and regulations. Store oil rags in
a bottom-ventilated, covered, metal container.
29. Keep hands and feet away from moving parts.
Do not reach over or across
equipment while operating.
30. Before use, check for misalignment or binding of
moving parts, breakage of parts, and any other
condition that may affect the equipment’s operation.
If damaged, have the equipment serviced
before using. Many accidents are caused
by poorly maintained equipment.
31. Use the correct equipment for the application.
Do not modify the equipment and do not use the
equipment for a purpose for which it is not intended.
3. Always make sure the hitch coupler is securely fixed
to the vehicle before moving it. If the Coupler is not
se cured properly, the link could come loose while
the trailer is in motion, possibly causing property
damage, SERIOUS PERSONAL INJURY, or DEATH.
4. Do not exceed 30 MPH when towing the Trencher.
5. Do not tow the Trencher on roads or
highways. This product is not D.O.T.
compliant, and is not road legal.
SAFETYSETUPOPERATIONMAINTENANCE
Service Precautions
1. Before service, maintenance, or cleaning:
a. Turn the engine switch to its “OFF” position.
b. Allow the engine to completely cool.
c. Then, remove the spark plug wire
from the spark plug.
2. Keep all safety guards in place and in
proper working order. Safety guards include
muffler, air cleaner, mechanical guards,
and heat shields, among other guards.
3. Do not alter or adjust any part of the
equipment or its engine that is sealed by the
manufacturer or distributor. Only a qualified
service technician may adjust parts that may
increase or decrease governed engine speed.
4. Wear ANSI-approved safety goggles,
heavy-duty work gloves, and
dust mask/respirator during service.
5. Do not allow the hydraulic hose to come in
contact with any hot part of the unit. The
hose might be damaged, possibly causing
it to burst or leak under high pressure.
6. Maintain labels and nameplates on the equipment.
These carry important information.
If unreadable or missing, contact
Harbor Freight Tools for a replacement.
7. Have the equipment serviced by a qualified repair
person using only identical replacement parts.
This will ensure that the safety of the equipment
is maintained. Do not attempt any service or
maintenance procedures not explained in this
manual or any procedures that you are uncertain
about your ability to perform safely or correctly.
8. Store equipment out of the reach of children.
9. Follow scheduled engine and
equipment maintenance.
Refueling:
1. Do not smoke, or allow sparks, flames,
or other sources of ignition around the
equipment, especially when refuelling.
2. Do not refill the fuel tank while the
engine is running or hot.
3. Refuel in a well-ventilated area only.
4. Wipe up any spilled fuel and allow excess
to evaporate before starting engine.
To prevent FIRE, do not start the engine
while the smell of fuel hangs in the air.
Read the ENTIRE IMPORTANT SAFETY INFORMATION section at the beginning of this manual
including all text under subheadings therein before set up or use of this product.
SAFETYSETUPOPERATIONMAINTENANCE
RISK OF ACCIDENTAL STARTING RESULTING IN SERIOUS PERSONAL INJURY.
Turn the Power Switch of the equipment to its “OFF” position, wait for the engine to cool, and
unplug the spark plug wire(s) before assembling or making any adjustments to the equipment.
The emission control system for this product’s Engine is warranted for standards set by
the U.S. Environmental Protection Agency and by the California Air Resources Board (also
known as CARB). For warranty information, refer to the last pages of this manual.
At high altitudes, the engine’s carburetor, governor (if so equipped), and any other parts that control
the fuel-air ratio will need to be adjusted by a qualified mechanic to allow efficient high-altitude
use and to prevent damage to the engine and any other devices used with this product.
Assembly
1. This equipment has a spark arresting muffler.
A spark arresting muffler is required by law in
California, on some US Forest Service land,
and possibly in other areas or situations.
2. Due to the size of the Trencher and its
components, assistance may be required
during the entire assembly process.
3. Use jacks (not included) to evenly raise
the Frame Assembly (90) & support
with jack stands (not included).
4. Mount both Axles (50) near the boom end of
the Frame and secure with Lock Pins (82).
5. Place a Tire (52) over the four studs on each
Hub. Secure the Tires to the Hubs, using
four Lug Nuts (53) per Tire. The Lug Nuts
must be snug. Inflate the Tires to 65 PSI.
6. Slightly raise the jacks, remove the jack stands,
then lower the jacks. Block the Tires and
tighten the Lug Nuts to at least 90 Ft-Lbs.
7. Attach Seat (73) to the Seat Bottom
Plate (10) and secure both Seat and Plate
to the post on top of Hydraulic Oil Tank.
8. Attach the Control Support (3) to the Frame
Assembly (90) using four Hex Bolts (81).
NOTE: The Hydraulics of this unit are tested
before shipment. There may be hydraulic fluid
present in components. Assemble the unit in
an area that will not be damaged by leaking
hydraulic fluid. It is recommended that you wrap
rags securely over the Hydraulic Connectors on
all the Cylinders during assembly. Wear splashresistant ANSI approved safety goggles and other
protective gear to prevent injury from leaking fluid.
9. Attach the Main Boom (36) to the Boom Pivot
(38) using the Pin (42) through the bottom hole
and Clevis Pin No. 1 (29) through the upper hole.
Secure both pins with Hair Pin Clip (31); Pin (42)
requires one Cotter pin on each end. See Figure A.
Boom
Pivot (38)
Pin
(42)
Figure A
10. Mount the Boom Extension (34) to the
Main Boom (36) using the Pin (42), left,
and Clevis Pin No. 1 (29), top. Secure
both pins with Hair Pin Clip (31).
11. Attach the Hitch Coupler (58) to the Frame
Assembly (90) under the Engine (74) using
Hex Bolts (75) and Hex HD. Bolt (72).
12. Connect, tighten, and check all hydraulic hose
fittings to the proper connections, as shown
in the Hose Connection Diagram. Hoses and
fittings are numbered. Tighten all fittings.
13. Open the Hydraulic Fluid Fill Plug (11). Top off
the Hydraulic Fluid Reservoir with high quality
hydraulic fluid. Check that the fluid level is
between the lines on the attached Dipstick.
Close the Hydraulic Fluid Fill Plug securely.
1. To use the Trencher, the Leg Assemblies must
be installed next to the Boom (36), and the
Wheels and Axles (50) moved to the rear.
2. Move the Trencher to the work area (See
Starting the Engine on page 10).
3. Start the engine and use the Boom Controls to curl
the Bucket toward the Boom without touching the
ground. Moving the Bucket As sembly (32) down
to the ground will raise the Frame Assembly (90).
Lift the Tires just off the ground and stop.
4. Ensure the controls will not be touched or bumped,
and that the Trencher will remain motionless. Never
place any part of your body under the Trencher.
Purging the Cylinder
1. Remove all Safety Locking Pins (15),
disengage the Safety Latch (41) and
loosen Hydraulic Tank Fill Plug (11).
2. Press forward on the Boom Swing Lever
(located on Control Panel (9) until the Boom
stops moving, then pull back on it until it moves
in the other direction. Center the Boom.
3. Press forward on the Main Boom Lever
until the Main Boom is fully raised. Then,
press Forward on the Boom Extension
Lever until the Boom is fully extended.
5. With the Tires (52) off the ground, remove the
Wheel and Axle (50) to the operator’s left and
replace with the left side Extension Leg (19) and
Leg Assembly (24). Direct the Extension Leg so
it turns toward the Bucket end of the Trencher.
Secure with Lock Pin No. 2 (82). Repeat procedure
for the right side. Raise Bucket As sembly again to
lower onto Leg Assembly, and turn Engine off.
6. Using a jack and jack stands (not included), raise
up the engine end of the Trencher and disconnect
from the Towing Hitch. Slide the Wheels and
Axles (50) into the engine end of the Frame (90).
Secure each Axle with Lock Pin No. 2 (82).
4. Press forward on the Bucket Lever until
the Bucket is fully extended. Pull back
on the Lever to retract it fully.
5. Pull back on the Boom Extension Lever
until the Boom is pulled back all the way.
Pull back on the Main Boom Lever until
the Main Boom is lowered completely.
6. Adjust the Boom back to its rest position
and replace all locking devices.
7. Shut off the Engine, check the Hydraulic
Fluid level and refill as necessary.
Note: The Fill Plug is vented. When tightening the
Fill Plug, tighten it securely then back it off slightly.
Read the ENTIRE IMPORTANT SAFETY INFORMATION section at the beginning of this manual
including all text under subheadings therein before set up or use of this product.
SAFETYSETUPOPERATIONMAINTENANCE
Pre-Start Checks
Inspect engine and equipment looking for damaged, loose, and missing parts before set up and starting.
If any problems are found, do not use equipment until fixed properly.
Checking and Filling Engine Oil
NOTICE: Your Warranty is VOID if the engine’s
crankcase is not properly filled with oil before
each use. Before each use, check the oil level.
Do not run the engine with low or no engine oil.
Running the engine with no or low engine oil
WILL permanently damage the engine.
1. Clean the Oil Filler Cap and the area around it.
2. Remove the Oil Filler Cap/Dipstick.
Read the engine service manual for the
proper way to check the oil level.
3. If the oil level is low, add the proper type and weight.
See information below.
Oil type:
32° F or above = SAE 10W-30
Below 32° F = SAE 5W-30.
4. Replace the Oil Filler Cap.
NOTICE: Do not run the engine with too little oil.
The engine will be permanently damaged.
Checking and Filling Fuel
WARNING! TO PREVENT SERIOUS
INJURY FROM FIRE:
Fill the fuel tank in a well-ventilated area
away from ignition sources. If the engine
is hot from use, shut the engine off and
wait for it to cool before adding fuel. Do not smoke.
1. Clean the Fuel Cap and the area around it.
2. Unscrew and remove the Fuel Cap.
3. Remove the Strainer and remove any dirt
and debris. Then replace the Strainer.
Note: Do not use gasoline containing more than
10% ethanol (E10). Do not use E85 ethanol. Add fuel
stabilizer to the gasoline or the Warranty is VOID.
Starting the Engine
Before Starting the Engine
Before starting the engine:
a. Follow the Set Up Instructions to prepare the equipment.
b. Inspect the equipment and engine.
c. Fill the engine with the proper amount and type of both unleaded gasoline and oil.
d. Read the Equipment Operation section that follows.
Note: Do not use gasoline that has been stored in a
metal fuel container or a dirty fuel container. It can
cause particles to enter the carburetor, affecting
engine performance and/or causing damage.
4. If needed, fill the Fuel Tank to about 1 inch under
the fill neck of the Fuel Tank with 90 octane or
higher unleaded gasoline that has been treated
with a fuel stabilizer additive. Follow fuel stabilizer
manufacturer’s recommendations for use.
5. Then replace the Fuel Cap.
6. Wipe up any spilled fuel and allow excess
to evaporate before starting engine.
To prevent FIRE, do not start the engine
while the smell of fuel hangs in the air.
1. Turn the Fuel Valve Lever to its “OPEN” position.
SAFETYSETUPOPERATIONMAINTENANCE
1
2. Turn the Ignition Switch to its ON or RUN position.
OFF
3. Then, turn the engine Choke Lever to its “START”
position. Set the Choke Lever in the “RUN” position
when starting a warm engine.
ON
O
I
ON
2
3
4. Grip the Starter Handle of the Engine loosely and pull it
slowly several times to allow the gasoline to flow into
the Engine’s carburetor. Then pull the Starter Handle
gently until resistance is felt. Allow Cable to retract fully
and then pull it quickly. Repeat until the engine starts.
Note: Do not let the Starter Handle snap back against
the engine. Hold it as it recoils so it doesn’t hit the engine.
5. Allow the Engine to run for several seconds.
Then, if the Choke Lever is in the CHOKE position,
move the Choke Lever very slowly to its RUN position.
Note: Moving the Choke Lever too
fast could stall the engine.