Harbor Freight Tools 420 cc, 346, 212 User Manual

Owner’s Manual & Safety Instructions

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.

212, 346 and 420 cc

Horizontal Engines

Using an engine indoors
CAN KILL YOU IN MINUTES.

Engine exhaust contains carbon monoxide.
This is a poison you cannot see or smell.

NEVER use inside
a home or garage,
EVEN IF doors and
windows are open.

Manual Revised 11k

When unpacking, make sure that the product is intact

and undamaged. If any parts are missing or broken,

please call 1-800-520-0882 as soon as possible.

Copyright© 2010 by Harbor Freight Tools®. All rights reserved.

No portion of this manual or any artwork contained herein may be reproduced in

any shape or form without the express written consent of Harbor Freight Tools.

Diagrams within this manual may not be drawn proportionally. Due to continuing

improvements, actual product may differ slightly from the product described herein.

Tools required for assembly and service may not be included.

Only use OUTSIDE
and far away from
windows, doors,
and vents.

Visit our website at: http://www.harborfreight.com

Email our technical support at: [e-mail]

ITEMS 68120, 68121,

68136, 68306

Read this material before using this product.
Failure to do so can result in serious injury.
SAVE THIS MANUAL.

Table of Contents

Specifications ............................................. 2

Safety ......................................................... 3

Setup .......................................................... 6

SAFETY OPERATION MAINTENANCESETUP

Operation .................................................... 8

Specifications

Description 68120, 68121 68136 68306

Displacement 212cc 346cc 420cc
Engine Type Horizontal Single Cylinder 4 stroke OHV
Cooling System Forced air cooled

Fuel

Engine Oil

Run Time @ 50% Load
with full tank

Sound Level at 22 feet 104 dB 108 dB 108 dB
Bore x Stroke 70 mm x 55 mm 83 mm x 64 mm 90 mm x 66 mm
Compression Ratio 8.5:1
Rotation viewed from PTO

(power takeoff - the output shaft)

Type 87+ octane unleaded gasoline
Capacity 1 Gallon 1 Gallon 1 Gallon

Type SAE

Capacity 0.5 Quart 1.16 Quart 1.16 Quart

Shaft 3/4″ x 2.41″ 1″ x 3.48″ 1″ x 3.48″

Maintenance .............................................. 14

Troubleshooting ......................................... 18

Warranties ................................................. 20

Parts Lists and Diagrams .......................... 22

10W-30 above 32° F

5W30 at 32° F or below

3 hr.

Counterclockwise

Shaft

Spark Plug

Valve Clearance

Speed Idle 1,800 ± 50 RPM

Keyway 3/16″ (4.76 mm) 1/4″ (6.35 mm) 1/4″ (6.35 mm)

End Tapped 5/16″ - 24 UNF 3/8″ - 24 3/8″ - 24

Type

Gap 0.7 - 0.8 mm

Intake 0.10 - 0.15 mm
Exhaust 0.15 - 0.20 mm

NGK® BP-6ES

NHSP® / Torch® F6TC

NHSP® / Torch® F6TC NHSP® / Torch® F6TC

Page 2 For technical questions, please call 1-800-520-0882. Horizontal Engines

WARNING SYMBOLS AND DEFINITIONS

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.

Symbol Definitions

Symbol Property 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.

Indicates a hazardous situation which, if not avoided,

could result in minor or moderate injury.

Addresses practices not related to personal injury.

Symbol Property 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.

SAFETYOPERATIONMAINTENANCE SETUP

Safety Warnings

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

Page 3For technical questions, please call 1-800-520-0882.Horizontal Engines

Set up Precautions

1. Gasoline fuel and fumes are flammable, and

potentially explosive. Use proper fuel storage

and handling procedures. Do not store fuel

SAFETY OPERATION MAINTENANCESETUP

or other flammable materials nearby.

2. Have multiple ABC class fire extinguishers nearby.

3. Operation of this equipment may create sparks
that can start fires around dry vegetation. A spark
arrestor may be required. The operator should
contact local fire agencies for laws or regulations
relating to fire prevention requirements.

Operating Precautions

1. CARBON MONOXIDE HAZARD

Using an engine indoors CAN KILL
YOU IN MINUTES.

Engine exhaust contains carbon
monoxide. This is a poison you cannot
see or smell.

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. Keep children away from the equipment,
especially while it is operating.

3. Keep all spectators at least six feet
from the Engine during operation.

4. Fire Hazard! Do not fill gas 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.

5. Do not touch engine during use. Let
engine cool down after use.

6. Never store fuel or other flammable
materials near the engine.

7. Only use a suitable means of transport and
lifting devices with sufficient weight bearing
capacity when transporting the Engine.

8. Secure the Engine on transport vehicles to
prevent the tool from rolling, slipping, and tilting.

9. Industrial applications must follow
OSHA requirements.

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.

10. 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.

11. Engine can produce high noise levels.
Prolonged exposure to noise levels above 85
dBA is hazardous to hearing. Always wear
ear protection when operating or working
around the gas engine while it is operating.

12. Wear ANSI-approved safety glasses, hearing
protection, and NIOSH-approved dust mask/
respirator under a full face shield along
with steel-toed work boots during use.

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. 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.

16. Stay alert, watch what you are doing and
use common sense when operating this
piece of equipment. Do not use this piece of
equipment while tired or under the influence
of drugs, alcohol or medication.

17. Do not overreach. Keep proper footing and
balance at all times. This enables better control
of the equipment in unexpected situations.

18. Use this equipment with both hands

only. Using equipment with only one hand

can easily result in loss of control.

19. 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.

Page 4 For technical questions, please call 1-800-520-0882. Horizontal Engines

Operating Precautions (cont.)

20. Parts, especially exhaust system components,
get very hot during use. Stay clear of hot parts.

21. Do not cover the engine or
equipment during operation.

22. Keep the equipment, engine, and
surrounding area clean at all times.

23. 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.

24. Do not operate the equipment with known
leaks in the engine’s fuel system.

25. 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.)

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

cap 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. Maintain labels and nameplates on the equipment.
These carry important information.
If unreadable or missing, contact
Harbor Freight Tools for a replacement.

6. 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.

7. Store equipment out of the reach of children.

26. 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.

27. Keep hands and feet away from moving parts. Do
not reach over or across equipment while operating.

28. 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.

29. 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.

8. 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. TO PREVENT FUEL LEAKAGE AND FIRE

HAZARD, do not fill fuel above the bottom of
fuel strainer for the 68121, 212cc engine.

68121 Max Fuel
DO NOT OVERFILL!

4. Do not fill fuel tank to the top. Leave a little
room for the fuel to expand as needed.

5. Refuel in a well-ventilated area only.

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.

SAFETYOPERATIONMAINTENANCE SETUP

SAVE THESE INSTRUCTIONS.

Page 5For technical questions, please call 1-800-520-0882.Horizontal Engines

Set Up

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.

SAFETY OPERATION MAINTENANCESETUP

TO PREVENT SERIOUS INJURY:
Operate only with proper spark arrestor installed.

Operation of this equipment may create sparks that
can start fires around dry vegetation.
A spark arrestor may be required.
The operator should contact local fire
agencies for laws or regulations relating
to fire prevention requirements.

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.

Battery Setup Instructions

Model 68120: The emission control system for this

engine is warranted for standards set by the U.S.

Environmental Protection Agency. For warranty
information, refer to the last pages of this manual.

Models 68306, 68121, and 68136: The emission
control system for this Generator’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.

WARNING! DO NOT INSTALL THIS
ENGINE ON A VEHICLE.

1. Place a fully charged, lead-acid 12 volt,
300 CCA, 36 Ah battery (not included) in

a stable, flat location near the engine.

2. Only use cables sized to match their length
according to the following chart:

Cable Gauge

(lower gauge numbers

mean thicker cables)

Maximum

Cable Length

6 5′
4 7′
2 12′

Motor Starter Assembly

Starting Relay

4. Attach the negative cable to the
negative battery terminal.

5. Connect the negative cable securely to one
of the engine mounting bolts, as shown in
the diagram below. Connect cable securely to
prevent disconnection and short circuits.

Connect Negative

Battery Cable to a

Mounting Bolt

6. Coat the terminals and cable ends with
a corrosion-preventive coating.

3.

Attach the positive cable from the positive
battery terminal to the Positive Terminal on
the starter solenoid (uncovered terminal),
shown above. Connect cable securely to
prevent disconnection and short circuits.

Page 6 For technical questions, please call 1-800-520-0882. Horizontal Engines

REV 11j

Engine Controls

Air Filter

Fuel Cap

SAFETYOPERATIONMAINTENANCE SETUP

Engine

Switch

(Electric

Start Models)

Starter
Handle

Muffler

Throttle

Choke

Oil Drain Plug

Fuel Valve

Dipstick

Starter

(Electric

Start Models)

Serial

Number

Location

(Write on front

cover of manual.)

Engine
Switch

(Manual Start

Models)

Page 7For technical questions, please call 1-800-520-0882.Horizontal Engines

Operation

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.

SAFETY OPERATION MAINTENANCESETUP

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. Make sure the engine is stopped and is level.

2. Close the Fuel Valve.

3. Clean the top of the Dipstick and the area around it.
Remove the Dipstick by threading it counterclockwise,
and wipe it off with a clean lint free rag.

Full level

4.

Reinsert the Dipstick without threading it in and
remove it to check the oil level. The oil level
should be up to the full level as shown above.

5. If the oil level is at or below the low mark add the
appropriate type of oil until the oil level is at the
proper level. SAE 10W-30 oil is recommended
for general use. (The SAE Viscosity Grade chart
on page 15 in the Service section shows other
viscosities to use in different average temperatures.)

6. Thread the dipstick back in clockwise.

NOTICE: Do not run the engine with too little oil.
The engine will be permanently damaged.

Full level

Page 8 For technical questions, please call 1-800-520-0882. Horizontal Engines

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. If needed, fill the Fuel Tank to about 1 inch
under the fill neck of the Fuel Tank with
87 octane or higher unleaded gasoline.

Starting the Engine

Before Starting the Engine

Before starting the engine:

a. Follow the Set Up Instructions in the equipment manual to prepare the equipment.
b. Inspect the equipment and engine.
c. Fill the engine with the proper amount and type of both fuel and oil.
d. Read the Equipment Operation section in the equipment manual.

Note: Do not use gasoline containing more than
10% ethanol (E10). Do not use E85 ethanol.

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. Then replace the Fuel Cap.

5. 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.

SAFETYOPERATIONMAINTENANCE SETUP

Page 9For technical questions, please call 1-800-520-0882.Horizontal Engines

Manual Start

SAFETY OPERATION MAINTENANCESETUP

1. To start a cold engine, move the Choke to the
CHOKE position.
To restart a warm engine, leave the Choke in the
RUN position.

2. Open the Fuel Valve.

1

CHOKE RUN

2

3. Slide the Throttle or Speed Control Lever to 1/3
away from the SLOW position (the “turtle”).

Note: Some tools have a Speed Control Lever located
elsewhere on the tool which functions the same as the

Throttle. Use the Speed Control Lever in place of the Throttle

when the tool is so equipped.

OFF

4. Turn the Engine Switch on.

3

ON

O

I

ON

4

5. 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.

Page 10 For technical questions, please call 1-800-520-0882. Horizontal Engines

5