Harbor Freight Tools 69736 Product 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.

420cc

Horizontal Engine

REV 15e

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.

Email our technical support at: [e-mail]

When unpacking, make sure that the product is intact

and undamaged. If any parts are missing or broken,

please call 1-888-866-5797 as soon as possible.

Copyright© 2012 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

ITEM 69736

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

Operation .................................................... 9

Specifications

Displacement 420cc

Engine Type

Cooling System Forced air cooled

Fuel

Engine Oil

Run Time @ 50% Load
with full tank

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

(power takeoff - the output shaft)

Shaft

Spark Plug

Valve Clearance

Speed Idle 1,800 ± 50 RPM

Type

Capacity 1 Gallon

Type SAE

Capacity 1.16 Quart

Shaft 1″ x 3.48″
Keyway 1/4″ (6.35 mm)
End Tapped 3/8″ - 24
Type NHSP® / Torch® F6TC
Gap 0.7 - 0.8 mm
Intake 0.10 - 0.15 mm
Exhaust 0.15 - 0.20 mm

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

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

Warranties ................................................. 23

Parts List and Diagram .............................. 20

Horizontal Single Cylinder 4 stroke OHV
EPA phase III compliant

87+ octane stabilizer treated
unleaded gasoline

10W-30 above 32° F
5W30 at 32° F or below

3 hr.

Counterclockwise

Page 2 For technical questions, please call 1-888-866-5797. ITEM 69736

Symbol Definitions

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.

Indicates a hazardous situation which, if not avoided,

could result in minor or moderate injury.

Addresses practices not related to personal injury.

SAFETYOPERATIONMAINTENANCE SETUP

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.

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.

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.

SAVE THESE INSTRUCTIONS

Page 3For technical questions, please call 1-888-866-5797.ITEM 69736

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 1-888-866-5797. ITEM 69736

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. 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.)

Service Precautions

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.

SAFETYOPERATIONMAINTENANCE SETUP

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.

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

4. Refuel in a well-ventilated area only.

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.

SAVE THESE INSTRUCTIONS.

Page 5For technical questions, please call 1-888-866-5797.ITEM 69736

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.

WARNING! DO NOT INSTALL THIS ENGINE ON A VEHICLE.
NOT FOR HIGHWAY USE. FOLLOW ALL APPLICABLE LAWS FOR INSTALLATION AND USE.

WARNING! If you do not connect a battery to the positive battery cable,
wrap its terminal securely with electrical tape (sold separately).

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.

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.

Battery Setup Instructions

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 1-888-866-5797. ITEM 69736

Engine Controls

Air Filter

Fuel Cap

SAFETYOPERATIONMAINTENANCE SETUP

Engine
Switch

Starter
Handle

Muffler

Throttle

Choke

Oil Drain Plug

Fuel Valve

Dipstick

Starter

Serial

Number

Location

(Write on front

cover of manual.)

Page 7For technical questions, please call 1-888-866-5797.ITEM 69736

High Altitude Operation Above 3000 feet

WARNING! TO PREVENT SERIOUS INJURY FROM FIRE:

Follow instructions 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 proceeding. Do not smoke.

SAFETY OPERATION MAINTENANCESETUP

NOTICE Warranty void if necessary adjustments are not made for high altitude use.

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. The fuel system on this engine may be influenced by
operation at higher altitudes. Proper operation can be ensured by installing an altitude kit at altitudes higher than
3000 ft. above sea level. At elevations above 8000 ft, the engine may experience decreased performance, even
with the proper main jet. Operating this engine without the proper altitude kit installed may increase the engine’s
emissions and decrease fuel economy and performance. The kit should be installed by a qualified mechanic.

1. Turn off the engine.

2. Close the fuel valve.

3. Place a bowl under the fuel cup to catch any spilled fuel.

CAUTION! Carburetor bowl may have gas in it which will leak upon removing the bolt.

4. Unthread the bolt holding the fuel cup.

5. Remove the bolt, Bolt Seal, fuel cup, Fuel Cup Seal and Main Jet from the body of the carburetor assembly.
A carburetor screwdriver (not included) is needed to remove and install the Main Jet.

Note: The mixing tube is held in place by the Main Jet and might fall out when it is removed.
If it falls out, replace it in the same orientation before replacing the Main Jet.

6. Replace the Main Jet with the replacement Main Jet needed for your altitude range (part 1a or 2a).

Note: The Fuel Cup Seal and Bolt Seal may be damaged during removal
and should be replaced with the new ones from the kit.

7. Replace the Fuel Cup Seal (4a), fuel cup,
Bolt Seal (3a), and bolt. Tighten in place.

Carburetor
Assembly

CAUTION: Do not cross thread bolt when tightening.

Finger tighten first and then use a wrench to

Fuel Cup Seal

make sure the bolt is properly threaded.

8. Wipe up any spilled fuel and allow excess to evaporate
before starting engine. To prevent FIRE, do not start the

Mixing Tube

(might remain
inside carburetor)

engine while the smell of fuel hangs in the air.

Main Jet

High Altitude Kit Parts List - A

Part Description Qty

1a Main Jet 3000-6000 ft. 1
2a Main Jet 6000-8000 ft. 1
3a Bolt Seal 1
4a Fuel Cup Seal 1

Fuel Cup

Bolt Seal

Bolt

Page 8 For technical questions, please call 1-888-866-5797. ITEM 69736