Honda GX31 User Manual

Owner’s Manual

GX22•GX31

The engine exhaust from this product

contains chemicals known to the State

of California to cause cancer, birth

defects or other reproductive harm.

Keep this owner’s manual handy, so you can refer to it at any time. This owner’s manual is considered a permanent part of the engine and should remain with the engine if resold.

The information and specifications included in this publication were in effect at the time of approval for printing. Honda Motor Co., Ltd. reserves the right, however, to discontinue or change specifications or design at any time without notice and without incurring any obligation whatever. No part of this publication may be reproduced without written permission.

INTRODUCTION

Congratulations on your selection of a Honda engine. We are certain you will be pleased with your purchase of one of the finest engines on the market.

We want to help you get the best results from your new engine and to operate it safely. This manual contains the information on how to do that; please read it carefully.

As you read this manual, you will find information preceded by a

symbol. That information is intended to help you avoid

damage to your engine, other property, or the environment.

We suggest you read the warranty policy to fully understand its coverage and your responsibilities of ownership. The warranty policy is a separate document that should have been given to you by your dealer.

When your engine needs scheduled maintenance, keep in mind that your Honda servicing dealer is specially trained in servicing Honda engines. Your Honda servicing dealer is dedicated to your satisfaction and will be pleased to answer your questions and concerns.

These engines are emissions-certified for use in handheld equipment. They can only be used to power products that are defined by the California Air Resources Board and the U.S. EPA as handheld.

Best Wishes, Honda Motor Co., Ltd.

INTRODUCTION

A FEW WORDS ABOUT SAFETY

Your safety and the safety of others are very important. And using this engine safely is an important responsibility.

To help you make informed decisions about safety, we have provided operating procedures and other information on labels and in this manual. This information alerts you to potential hazards that could hurt you or others.

Of course, it is not practical or possible to warn you about all the hazards associated with operating or maintaining an engine. You must use your own good judgment.

You will find important safety information in a variety of forms, including:

Safety Messages

of three signal words, DANGER, WARNING, or CAUTION.

These signal words mean:

Safety Headings

Safety Section

Instructions

This entire book is filled with important safety information –– please read it carefully.

–– preceded by a safety alert symbol and one

You WILL be KILLED or SERIOUSLY HURT if you don’t follow instructions.

You CAN be KILLED or SERIOUSLY HURT if you don’t follow instructions.

You CAN be HURT if you don’t follow instructions.

–– such as

–– how to use this engine correctly and safely.

IMPORTANT SAFETY INFORMATION.

ENGINE SAFETY.

.......................................................................................ENGINE SAFETY . 5

............................................................................................CONTROLS . 8

.......................................................................................Choke Lever . 8

...........................................................................................FEATURES . 11

............................................................................................OPERATION . 14

.......................................................................................Hot Restart . 16

................................................IMPORTANT SAFETY INFORMATION . 5

........................................................................CONTROLS & FEATURES . 7

............................................COMPONENT & CONTROL LOCATIONS . 7

....................................................................................Throttle Lever . 9

...........................................................................Recoil Starter Grip . 10

...........................................................................Centrifugal Clutch . 11

.............................................................................BEFORE OPERATION . 12

.....................................................IS YOUR ENGINE READY TO GO? . 12

..................................Check the General Condition of the Engine . 12

.............................................................................Check the Engine . 13

............................Check the Equipment Powered by This Engine . 13

...................................................SAFE OPERATING PRECAUTIONS . 14

....................................................................STARTING THE ENGINE . 14

....................................................................STOPPING THE ENGINE . 17

...................................................................SETTING ENGINE SPEED . 18

.....................................................SERVICING YOUR HONDA ENGINE . 19

............................................THE IMPORTANCE OF MAINTENANCE . 19

....................................................................MAINTENANCE SAFETY . 20

..............................................................MAINTENANCE SCHEDULE . 21

..........................................................................................REFUELING . 22

.............................................................FUEL RECOMMENDATIONS . 23

................................................................ENGINE OIL LEVEL CHECK . 24

.........................................................................ENGINE OIL CHANGE . 26

..................................................ENGINE OIL RECOMMENDATIONS . 28

....................................................................AIR FILTER INSPECTION . 29

.......................................................................AIR FILTER CLEANING . 30

.......................................................................SPARK PLUG SERVICE . 31

...............................................................COOLING FIN INSPECTION . 33

.................FUEL FILTER INSPECTION and FUEL TANK CLEANING . 34

..............................................................SPARK ARRESTER SERVICE . 36

CONTENTS

...........................................................................................Air Index . 52

..........................................................HELPFUL TIPS & SUGGESTIONS .40

...................................................................STORING YOUR ENGINE . 40

........................................................................Storage Preparation . 40

........................................................................Storage Precautions . 43

...................................................................Removal From Storage . 43

.................................................................................TRANSPORTING . 44

.....................................TAKING CARE OF UNEXPECTED PROBLEMS . 45

.................................................................ENGINE WILL NOT START . 45

.....................................................................ENGINE LACKS POWER . 45

........................................TECHNICAL & CONSUMER INFORMATION . 46

...............................................................TECHNICAL INFORMATION . 46

..................................................................Serial Number Location . 46

.................................................................Remote Control Linkage . 47

..................Carburetor Modification for High Altitude Operation . 48

...........................................................................Oxygenated Fuels . 49

..........................................Emission Control System Information . 50

..................................................................................Specifications . 53

...............................................................................Wiring Diagram . 54

..............................................................CONSUMER INFORMATION . 55

.........................................................................Honda Publications . 55

........................................................Warranty Service Information . 56

............................QUICK REFERENCE INFORMATION . Inside back cover

ENGINE SAFETY

IMPORTANT SAFETY INFORMATION

Most accidents with engines can be prevented if you follow all instructions in this manual and on the engine. Some of the most common hazards are discussed below, along with the best way to protect yourself and others.

Owner Responsibilities

Honda engines are designed to give safe and dependable service if operated according to instructions. Read and understand this owner’s manual before operating the engine. Failure to do so could result in personal injury or equipment damage.

Know how to stop the engine quickly, and understand the operation of all controls. Never permit anyone to operate the engine without proper instructions.

Do not allow children to operate the engine. Keep children and pets away from the area of operation.

Refuel With Care

Gasoline is extremely flammable, and gasoline vapor can explode. Refuel outdoors, in a well-ventilated area, with the engine stopped. Never smoke near gasoline, and keep other flames and sparks away. Always store gasoline in an approved container. If any fuel is spilled, make sure the area is dry before starting the engine.

ENGINE SAFETY

Hot Exhaust

The muffler becomes very hot during operation and remains hot for a while after stopping the engine. Be careful not to touch the muffler while it is hot. Let the engine cool before storing it indoors.

Carbon Monoxide Hazard

Exhaust gas contains poisonous carbon monoxide. Avoid inhalation of exhaust gas. Never run the engine in a closed garage or confined area.

Other Equipment

Review the instructions provided with the equipment powered by this engine for any additional safety precautions that should be observed in conjunction with engine startup, shutdown, operation, or protective apparel that may be needed to operate the equipment.

CONTROLS & FEATURES

COMPONENT & CONTROL LOCATIONS

Horizontal type:

SPARK PLUG

CHOKE LEVER

AIR CLEANER

PRIMING BULB

FUEL FILLER CAP

MUFFLER (inside the cover)

STARTER GRIP

Vertical type:

MUFFLER (inside the cover)

SPARK PLUG

CHOKE LEVER

FUEL TANK

OIL FILLER CAP

SPARK ARRESTER

RECOIL STARTER

STARTER GRIP

FUEL FILLER CAP

OIL FILLER CAP

FUEL TANK

PRIMING BULB

AIR CLEANER

CONTROLS & FEATURES

CONTROLS

Choke Lever

The choke lever opens and closes the choke valve in the carburetor.

The CLOSED position enriches the fuel mixture for starting a cold engine.

The OPEN position provides the correct fuel mixture for operation after starting, and for restarting a warm engine.

CHOKE LEVER

CCLLOOSSEEDD

OOPPEENN

CONTROLS & FEATURES

Throttle Lever

The throttle lever controls engine speed.

Moving the throttle lever in the directions shown makes the engine runfasterorslower.

The throttle lever shown here will be connected to a remote control on the equipment powered by this engine. Refer to the instructions provided with that equipment for remote control information.

THROTTLE LEVER

SSLLOOWW

FFAASSTT

CONTROLS & FEATURES

Recoil Starter Grip

Pulling the starter grip operates the recoil starter to crank the engine.

Horizontal type:

STARTER GRIP (EQUIPMENT SIDE)

Vertical type:

(EQUIPMENT SIDE)

STARTER GRIP

CONTROLS & FEATURES

FEATURES

Centrifugal Clutch

The centrifugal clutch automatically engages and transmits power when engine speed is increased above approximately 4,000 rpm. At idle speed, the clutch is disengaged.

Do not run the engine without mounting it on equipment that includes the centrifugal clutch drum and housing, or centrifugal force will cause the clutch shoes to contact and damage the engine case.

BEFORE OPERATION

IS YOUR ENGINE READY TO GO?

For your safety, and to maximize the service life of your equipment, it is very important to take a few moments before you operate the engine to check its condition. Be sure to take care of any problem you find, or have your servicing dealer correct it, before you operate the engine.

Improperly maintaining this engine, or failing to correct a problem before operation, could cause a malfunction in which you could be seriously injured.

Always perform a preoperation inspection before each operation, and correct any problem.

Before beginning your preoperation checks, be sure the engine is level and the ignition switch on the equipment is in the OFF position.

Check the General Condition of the Engine

Look around and underneath the engine for signs of oil or gasoline leaks.

Remove any excessive dirt or debris, especially around the muffler and recoil starter.

Look for signs of damage.

Check that all shields and covers are in place, and all nuts, bolts, and screws are tightened.

Check the Engine

BEFORE OPERATION

Check the engine oil level (see page ). Running the engine with a low oil level can cause engine damage.

Check the air filter (see page ). A dirty air filter will restrict air flow to the carburetor, reducing engine performance.

Check that all nuts, bolts, and screws are tightened.

Check the fuel level. Starting with a full tank will help to eliminate or reduce operating interruptions for refueling.

Check the Equipment Powered by This Engine

Review the instructions provided with the equipment powered by this engine for any precautions and procedures that should be followed before engine startup.

OPERATION

SAFE OPERATING PRECAUTIONS

Beforeoperatingtheengineforthefirsttime,pleasereviewthe

IMPORTANT SAFETY INFORMATION BEFORE OPERATION

Review the instructions provided with the equipment powered by this engine for any safety precautions that should be observed in conjunction with engine startup, shutdown, or operation.

STARTING THE ENGINE

Carbon monoxide gas is toxic. Breathing it can cause unconsciousness and even kill you.

Avoid any areas or actions that expose you to carbon monoxide.

on page and the chapter titled

To start a cold engine, move the choke lever to the CLOSED position.

To restart a warm engine, leave the choke lever in the OPEN position.

CCLLOOSSEEDD

OOPPEENN

CHOKE LEVER

OPERATION

Press the priming bulb repeatedly until fuel can be seen in the clear-

2. plastic fuel-return tube.

FUEL RETURN TUBE (clear plastic tube)

PRIMING BULB

Turn the ignition switch to the ON position.

Pull the starter grip lightly until you feel resistance, then pull briskly.

4. Return the starter grip gently.

Horizontal type: Vertical type:

STARTER GRIP

(EQUIPMENT SIDE)

STARTER GRIP

OPERATION

If the choke lever was moved to the CLOSED position to start the engine, gradually move it to the OPEN position as the engine warms up.

CHOKE LEVER

OOPPEENN

Hot Restart

If the engine is operated at higher ambient temperatures then turned off and allowed to sit for a short time, if may not restart on the first pull.

If necessary, use the following procedure:

The ignition switch and the throttle lever are located on the equipment not on the engine.

IMPORTANT SAFETY PRECAUTION

Turn the ignition switch to the OFF position before performing the following procedure. This will prevent the engine from starting and running at maximum speed when the throttle is in the full throttle position. If the engine starts, with the throttle in the full throttle position, the equipment can move forward rapidly or the trimmer attachment can spin at maximum speed. This may result in personal injury.

Turn the ignition switch to the OFF position.

Move the choke lever to the OPEN position.

Hold the throttle lever in the full throttle position.

Pull the starter grip 3 to 5 times.

Follow the STARTING THE ENGINE procedure on page and start the engine with the choke lever in the OPEN position.

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