Honda umc435, umc425 Owner's Manual

INTRODUCTION

The engine exhaust from this product

contains chemicals known to the State of

California to cause cancer, birth defects or

other reproductive harm.

INTRODUCTION.................... 1

SAFETY MESSAGES.............. 1

SAFETY INFORMATION ......... 2

SAFETY LABEL LOCATION..... 4

COMPONENT & CONTROL

LOCATIONS ......................... 4

CONTROLS .......................... 5

BEFORE OPERATION

CHECKS .............................. 6

OPERATION ......................... 9

SAFE OPERATING

PRECAUTIONS................... 9

STARTING THE ENGINE .... 10

SETTING ENGINE SPEED... 11

STOPPING THE ENGINE .... 11

SERVICING YOUR

POWERHEAD...................... 11

THE IMPORTANCE OF

MAINTENANCE................ 11

MAINTENANCE SAFETY ... 11

SAFETY PRECAUTIONS .... 12

MAINTENANCE

SCHEDULE ...................... 12

REFUELING...................... 13

ENGINE OIL ..................... 13

Recommended Oil.......... 13

Oil Level Check ............. 13

Oil Change.................... 14

AIR CLEANER .................. 15

Inspection..................... 15

Cleaning....................... 15

THROTTLE CABLE............ 15

Check and Adjustment ... 15

Free Play Inspection....... 15

SPARK PLUG....................16

COOLING FINS .................17

FUEL FILTER AND FUEL

TANK ..............................17

FUEL TUBE ......................17

SPARK ARRESTER ............ 18

HELPFUL TIPS &

SUGGESTIONS....................19

STORING YOUR

POWERHEAD ...................19

TRANSPORTING ............... 20

TAKING CARE OF

UNEXPECTED PROBLEMS.....21

TECHNICAL & CONSUMER

INFORMATION ....................21

Serial Number Location......21

Carburetor Modifications for

High Altitude Operation .....22

Emission Control System

Information ......................22

Air Index..........................22

Specifications...................23

Tuneup Specifications ....... 23

Quick Reference

Information ......................23

CONSUMER INFORMATION ... 24

Customer Service

Information ......................24

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Thank you for purchasing a Honda powerhead. We want to help
you to get the best results from your new powerhead and to
operate it safely.
This manual contains information on how to do that; please read it
carefully before operating the powerhead. If a problem should arise,
or if you have any questions about your powerhead, consult an
authorized Honda servicing dealer.

All information in this publication is based on the latest product
information available at the time of printing. Honda Motor Co., Ltd.
reserves the right to make changes at any time without notice and
without incurring any obligation. No part of this publication may be
reproduced without written permission.

This manual should be considered a permanent part of the
powerhead and should remain with the powerhead if resold.

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.

SAFETY MESSAGES

Your safety and the safety of others are very important. We have
provided important safety messages in this manual and on the
powerhead. Please read these messages carefully.

A safety message alerts you to potential hazards that could hurt
you or others. Each safety message is preceded by a safety alert

symbol and one of three words, DANGER, WARNING, or
CAUTION.

OWNER’S MANUAL

UMC425∙UMC435

POWERHEAD

California Proposition 65

This product contains or emits

chemicals known to the state of

California to cause cancer, birth defects

or other reproductive harm

These signal words mean:

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

You CAN be KILLED or SERIOUSLY

Each message tells you what the hazard is, what can happen, and
what you can do to avoid or reduce injury.

DAMAGE PREVENTION MESSAGES

You will also see other important messages that are preceded by
the word NOTICE.

This word means:

The purpose of these messages is to help prevent damage to your
powerhead, other property, or the environment.

The illustrations in this manual are based on: UMC435

• The illustrations may vary according to the type.

2015 Honda Motor Co., Ltd. –All Rights Reserved

31VP8600
00X31-VP8-6000

Your powerhead or other property can be damaged if
you don’t follow instructions.

HURT if you don’t follow instructions.

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

UMC425A∙UMC435A

CONTENTS

1

SAFETY INFORMATION

HARD HAT

EAR HEARING
PROTECTION

CLOTHES (LONG SLEEVE)

CLOTHES (LONG PANTS)

LEG PROTECTORS

SAFETY BOOTS (WITH
TOE PROTECTOR)

GLOVES

FACE SHIELD

EYE PROTECTION

ARM COVERS

Operator Responsibility

• Understand the operation of all controls and learn how to stop
the engine quickly in case of an emergency. Make sure the
operator receives adequate instruction before operating the
equipment.

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

• Your powerhead’s exhaust contains poisonous carbon monoxide.
Do not run the engine without adequate ventilation, and never
run the engine indoors.

• The powerhead and exhaust become very hot during operation.

• Only use Honda approved attachments. If not, injury or accident
may occur.

• Read and follow the instructions in the owner’s manual that
came with each attachment.

• Never operate the powerhead when tired, ill, or under the
influence of alcohol or other drugs.

• Any part of the machine is a potential source of danger if the
machine is used in abnormal conditions or if the maintenance is
not performed correctly.

• If you lend or resell your powerhead to a third person, instruct
him or her on how to handle the product and alert him or her to
read the Owner’s Manual carefully before operation.

• Follow the instructions in the owner’s manual that comes with
each attachment.

• Keep in mind that the operator or user is responsible for any
accidents or hazards that may occur to other people or their
property.

• While operating the powerhead, always wear protective clothing
and protective devices.

• Follow the instructions in the owner’s manual that comes with
each attachment, regarding required protective clothing and
protective devices. For example:
– Protective clothing

Wear adequate clothes with long sleeves and long pants.
Do not wear loose or baggy clothing.
Arm covers and leg protectors should be worn.
Do not wear anything around your neck (for example necklaces
or neckties).
Tie your hair if it is long.

– Protective devices

* Eye protection

Eye protection should meet the requirements of ANSI Z87.1.
Wear goggles or other eye protection to protect your eyes
from flying debris.

*Hard hat

Wear a hard hat to protect your head from any overhead
branches and falling foreign material.

* Face shield

Wear a face shield to protect your face from flying debris.

* Ear hearing protection

To reduce the risk of hearing loss, hearing protection is
required.

*Gloves

Wear gloves to protect your hands.

* Safety boots

Wear safety boots with a non-slip sole and toe protector to
protect your feet from falling objects and flying debris.
Do not operate the equipment barefoot or wearing open
sandals.

* Leg protectors

We recommend that you wear the leg protectors to protect
your legs.

*Dust mask

We recommend that you wear a dust mask to protect
yourself from dusts and pollens.

• Before each use, visually inspect the powerhead for any damage
and looseness of parts.

• Before each use, look around and underneath the engine for signs
of oil or gasoline leaks.

• Avoid operating the powerhead at night, poor visibility or in bad
weather.

• Walk, never run during operation.

• Avoid operating the powerhead on a steep slope.
The steep slope may be slippery, causing you to fall.

• Do not operate the powerhead with any labels, or any parts
removed.

• Do not tamper with the powerhead as it can result in personal
injury and/or equipment damage.

• Only use attachments that are designed for your model and
application.

• Stop the engine with the engine switch to the OFF position in the
following cases:
– Before any operation around the powerhead.
– Before checking, cleaning or working on the powerhead.
– After striking a foreign object. Inspect the powerhead for

damage and make repairs before restarting the powerhead.

– If the powerhead starts to vibrate abnormally. Check

immediately the cause of the vibration and perform the

necessary repair.
– Whenever you leave the powerhead unattended.
– Before refueling.
– When any person or pet is approaching.
– Shut off the engine immediately when the powerhead shows

abnormal vibration suddenly. Sudden vibration can suggest the

damaged rotating parts or loose fasteners. Examine the cause

of the problem, and do not start the engine before a repair is

made.

• The attachment should not be moving when the engine is at idle.
If this happens, contact your authorized Honda dealer. This idle
speed will need to be adjusted. Make sure the cutting attachment
has stopped before the unit is set down.

• Keep all nuts, bolts and screws tight to be sure the powerhead is
in a safe working condition. Regular maintenance is essential to
user’s safety and product performance.

• Do not use the powerhead with worn or damaged parts. Parts
must be replaced, or repaired. Replace worn or damaged parts
with Honda genuine parts. Non equivalent quality parts may
damage the machine and be prejudicial to your safety.

2

• Injury caused by vibration and cold:
You may feel the prickling or burning pain in your fingers, and the
fingers may lose color and feeling. It is believed that these
symptoms are brought by vibration and/or exposure to cold. The
specific trigger point of these symptoms are not identified yet,
but observe the following instructions.

* Limit the amount of time you spend operating the powerhead

in a day.

* Keep your body warm, especially your hands, wrists and

arms.

* Take your breaks at short intervals. Do not smoke while

working.

* When you feel discomfort, redness and swelling of the

fingers followed by whitening and loss of feeling, consult
your doctor promptly.

• Injury caused by repeated operation:
Performing the repeated operation for a prolonged time may
cause injury. Observe the following instructions to reduce the
causes of the injury.

* Avoid repeated operation by using your wrist(s) in bent,

stretched or twisted position.

* Take your breaks regularly to minimize the effect of repeated

operation. Take your time when performing repeated
operation. Do not rush to operate the powerhead.

* When your fingers, hands, wrists and/or arms are throbbing

or numbed, consult your doctor.

Carbon Monoxide Hazard

Your powerhead’s exhaust contains poisonous carbon monoxide
gas, which you cannot see or smell. Breathing carbon monoxide
can KILL YOU IN MINUTES,
For your safety:

• Do not start or operate the engine in any closed or partially
enclosed area, such as a garage.

• Never run the powerhead in closed or even partially closed area
where people or pets may be present.

• Never operate the powerhead near open doors, windows, or
vents.

• Get fresh air and seek medical attention immediately if you
suspect you have inhaled carbon monoxide.

Early symptoms of carbon monoxide exposure include headache,
fatigue, shortness of breath, and dizziness. Continued exposure to
carbon monoxide can cause loss of muscular coordination, loss of
consciousness, and then death.

Child Safety

• Keep children indoors and supervised at all times when any
outdoor powerhead is being used nearby.

• Never assume children will remain where you last saw them. Be
alert and turn the powerhead off if children enter the area.

• Children should never be allowed to operate the powerhead, even
under adult supervision.

Fire and Burn Hazard

Gasoline is extremely flammable, and gasoline vapor can explode.
Use extreme care when handling gasoline. Keep gasoline out of
reach of children.

• Store fuel in containers specifically designed for this purpose.

• Refuel outdoors only, and do not smoke while refueling or
handling fuel.

• Add fuel before starting the engine. Never remove the cap of the
fuel tank or add gasoline while the engine is running or when the
engine is hot.

• If gasoline is spilled, do not attempt to start the engine but move
the powerhead away from the area of spillage and avoid creating
any source of ignition until gasoline vapors have dissipated.

• Tighten the fuel tank and container cap securely.

• When you start the engine after refueling, be sure to start the
engine at least 10 feet (3 meter) away from the refueling spot.

• Never store the powerhead with gasoline in the tank inside a
building where fumes may reach an open flame, spark or high
temperature source.

• Allow the engine to cool before storing in any enclosure.

• To reduce a fire hazard, keep the powerhead, especially the
engine, muffler, and gasoline storage area, free of grass, leaves,
or excessive grease.

• If the fuel tank has to be drained, this should be done outdoors,
with a cold engine.

3

SAFETY LABEL LOCATION

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.

Per California Public Resources Code 4442.6

THROTTLE TRIGGER
INTERLOCK

ENGINE SWITCH

LOOP HANDLE

MAIN PIPE

SET PIN KNOB

JOINT KNOB

PROTECTOR

HANGER

THROTTLE TRIGGER

SPARK PLUG

SPARK PLUG CAP
(inside the top cover)

TOP COVER

AIR CLEANER

PRIMING PUMP

CHOKE LEVER

FUEL RETURN TUBE
(TRANSPARENT TUBE)

FUEL TUBE (BLACK TUBE)

FUEL TANK CAP

STARTER GRIP

ENGINE OIL FILLER CAP

MUFFLER

These labels warn you of potential hazards that can cause serious
injury. Read them carefully.
If a label comes off or becomes hard to read, contact your Honda
servicing dealer for replacement.

COMPONENT & CONTROL LOCATIONS

* The following Honda approved attachments can be used with the

powerhead. Consult your servicing dealer.

• Trimmer/Brush

• Edger
∙∙∙etc.

4

CONTROLS

OFF ON

ENGINE SWITCH

OFF

ON

PRIMING PUMP

CHOKE LEVER

OPEN

CLOSED

OPEN

CLOSED

STARTER GRIP

THROTTLE TRIGGER
INTERLOCK

FAST

SLOW

THROTTLE TRIGGER

Starter Grip

Engine Switch

The engine switch enables and disables the ignition system.
The engine switch must be in the ON position for the engine to run.
Moving the engine switch to the OFF position stops the engine.

Priming Pump

Pressing the priming pump feeds the gasoline from the fuel tank to
the carburetor. This procedure is necessary for starting the engine
(see page 10).

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

Throttle Trigger

The throttle trigger controls engine speed.
Pulling and releasing the throttle trigger shown below makes the
engine run faster or slower.

The throttle trigger interlock must be depressed before the throttle
trigger can be activated.

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.

By pulling the throttle trigger gradually, the engine speed increases
gradually.
Pull the throttle trigger more to accelerate the engine speed.
By releasing the throttle trigger, the engine speed decreases.

Throttle Trigger Interlock:

The throttle trigger interlock makes the throttle trigger operable.
The throttle trigger cannot be pulled unless the throttle trigger
interlock has been pushed beforehand.

5

Joint

JOINT

QUICK-RELEASE LATCH TAB

CARRYING
HARNESS

QUICK-RELEASE LATCH

BEFORE OPERATION CHECKS

The joint is to attach a Honda approved attachment to the
powerhead.
Refer to Pages 7–8 for how to attach and detach the attachments.

Carrying Harness Quick-Release Latch

The quick-release latch tab is provided to detach the powerhead
from your body in an emergency.
Pull up the quick-release latch tab, and the powerhead is detached
from the carrying harness.

IS YOUR POWERHEAD READY TO GO?

For your safety, to ensure compliance with environmental
regulations, and to maximize the service life of your equipment, it is
very important to take a few moments before you operate the
powerhead 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 powerhead.

Improperly maintaining this powerhead, or failing to
correct a problem before operation, could cause a
malfunction.

Some malfunctions can seriously hurt or kill you.

Always perform a pre-operation inspection before
each operation and correct any problems.

Before beginning your pre-operation checks, be sure the powerhead
is level and the engine switch is in the OFF position.

Always check the following items before you start the engine:

Check the General Condition of the Powerhead

1. Before each use, look around and underneath the engine for
signs of oil or gasoline leaks.

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

3. Look for signs of damage.

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

Adjustment of the Carrying Harness

Failure to wear the carrying harness while using the
powerhead could result in instability.

Injuries may occur due to instability.

Be sure to wear the carrying harness before using the
powerhead.

1. Wear the carrying harness so that the hip pad is on the right
side of your body.

• Make sure the harness does not twist.

• If the carrying harness is for both shoulders, firmly secure the

carrying harness latch on the front of your body until it clicks.
To unlock the carrying harness latch, pull the harness to the
right and to the left while pressing the latch.

6

2. Adjust the length of the harness as shown in the figures below.

For both shoulders

(UMC435)

For single shoulders

(UMC425)

CARRYING
HARNESS

CARRYING
HARNESS

HIP PAD

CARRYING
HARNESS
LATCH

HIP PAD

To make it shorter To make it longer

1

2

2

1

(UMC435) (UMC425)

Roll the end of the
harness and fasten it.
(There is one applicable
point on the back side of
your body)

Roll the end of the
harness and fasten it.

QUICK-RELEASE
LATCH TAB

HOOK

QUICK-RELEASE
LATCH

HIP PAD

LATCH TONGUE

SLOT

JOINT HOLDER SET PIN KNOB (Back side of the portion where

the attachment is connected)

KEY

PROJECTION

JOINT KNOB

ATTACHMENT

JOINT HOLDER

GROOVE

LOOSEN

LOCK

1

2

3

3. Insert the latch tongue in the slot of the quick-release latch to
reattach the powerhead to the carrying harness.

If the latch is not released, have your device inspected and repaired
by your servicing dealer.

Attachment Installation/Removal

Check the joint area:

1. Check to see if the set pin knob moves smoothly.

3. Roll the end of the harness toward your body and fasten it.

Check the Quick-Release Latch

1. Put on the carrying harness.

2. Check that the latch is released as soon as the quick-release
latch tab is pulled upwards while holding the hip pad with your
left hand.

2. Check to see if the joint knob tightens and loosens smoothly,
and if there is any damage.

3. Make sure there is no debris in the groove and inside the joint
holder.

Installation:

Running this engine without an attachment in place
could cause an unsafe condition.

Moving parts could cause severe injury.

Do not run the engine without an attachment properly
secured.

1. Turn the set pin knob to the lock position and loosen the joint
knob.

2. Align the “ ” mark on the attachment with the joint projection
which also aligns the key of the attachment with the joint
groove.

7

3. Insert the attachment until the set pin knob clicks. Confirm the

JOINT HOLDER

ATTACHMENT

SET PIN KNOB

JOINT HOLDER

ATTACHMENT

JOINT KNOB

TIGHTEN

4

5

SET PIN KNOB

UNLOCK

JOINT KNOB

LOOSEN

1

2

MAIN PIPE

ATTACHMENT

POWERHEAD SIDE

SET PIN KNOB

LOCK

“ ” mark on the attachment is at the joint holder end.

4. Pull the attachment and joint holder to the arrow direction to
check that the attachment will not come loose.

5. Tighten the joint knob.

3. Hold the main pipe on the powerhead side and detach the
attachment.

4. Turn the set pin knob to the lock position.

Check the Engine

When you place the powerhead with the recoil starter facing
down, be careful not to damage the recoil starter. Recoil starter
or the engine might get damaged from the impact.

Removal:

Be sure to turn the engine switch to the OFF position.
The attachment will continue to move briefly after the
engine has stopped or the throttle trigger is released.

A moving attachment can cause injury.

Maintain proper control of the powerhead until the
attachment has completely stopped moving.

1. Loosen the joint knob.

2. Pull the set pin knob up and twist 90 degrees to the unlock
position.

1. Check the fuel level (see page 13). Starting with a full tank will
help to eliminate or reduce operating interruptions for refueling.

2. Check the engine oil level (see page 13). Running the engine
with a low oil level can cause engine damage.

3. Check the air filter element (see page 15). A dirty air filter
element will restrict air flow to the carburetor, reducing engine
and powerhead performance. A damaged air filter element will
allow dust to enter and damage the engine.

4. Check the throttle cable free play (see page 15). Operate the
throttle system several times and check if it the free play (i.e.
throttle lever does not move while operating the throttle
trigger).

8