Yanmar By series User manual

series

SERVICE MANUAL

BY Service Manual

4BY2

6BY2

P/N: 0BBY0-U00200

MARINE

ENGINES

ii BY Service Manual

This Service Manual has been developed for the exclusive use of service and repair professionals such as

Yanmar authorized Distributors and Yanmar authorized Dealers. It is written with these professionals in mind

and may not contain the necessary detail or safety statements that may be required for a non-professional to

perform the service or repair properly and / or safely. Please contact an authorized Yanmar repair or service

professional before working on your Yanmar product.

Disclaimers:

All information, illustrations and specifications in this manual are based on the latest information available at

the time of publishing. The illustrations used in this manual are intended as representative reference views

only. Moreover, because of our continuous product improvement policy, we may modify information,

illustrations, and / or specifications to explain and / or exemplify a product, service, or maintenance

improvement. We reserve the right to make any change at any time.

Yanmar and are registered trademarks of Yanmar Co., Ltd. in Japan, the United States and / or

other countries.

No part of this publication may be reproduced or used in any form by any means - graphic, electronic, or

mechanical, including photocopying, recording, taping, or information storage and retrieval systems - without

the written permission of Yanmar Marine International.

0409

BY Service Manual iii

BY Service Manual TABLE OF

CONTENTS

Page

Safety.................................................................................................... 2-1

Safety Precautions .......................................................................... 2-2

General Service Information .............................................................. 3-1

Safety Precautions .......................................................................... 3-3

Engine Outline Drawings................................................................. 3-4

4BY2 (Inboard) .......................................................................... 3-4

4BY2 (Stern Drive) .................................................................... 3-5

6BY2 (Inboard) .......................................................................... 3-6

6BY2 (Stern Drive) .................................................................... 3-7

Engine Piping Diagrams.................................................................. 3-8

4BY2.......................................................................................... 3-8

6BY2.......................................................................................... 3-9

Location of Nameplates................................................................. 3-11

Engine Nameplates (Typical) .................................................. 3-11

Diesel Fuel .................................................................................... 3-12

Diesel Fuel Specifications ....................................................... 3-12

Bleeding the Fuel System........................................................ 3-14

Engine Oil...................................................................................... 3-14

Engine Oil Specifications......................................................... 3-14

Acceptable Engine Oil ............................................................. 3-16

Recommended Marine Gear or Stern Drive Oil....................... 3-18

Recommended Power Steering Fluid...................................... 3-18

Engine Coolant.............................................................................. 3-19

Engine Coolant Specifications................................................. 3-19

Acceptable Engine Coolant ..................................................... 3-20

Principal Engine Specifications ..................................................... 3-21

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iv BY Service Manual

Tightening Torques for Standard Bolts and Nuts .......................... 3-23

Tightening Fasteners............................................................... 3-23

Hexagon Bolts and Nuts.......................................................... 3-23

Hose Clamps........................................................................... 3-23

Prepare Engine for Long-Term Storage........................................ 3-24

Abbreviations and Symbols........................................................... 3-25

Abbreviations........................................................................... 3-25

Symbols................................................................................... 3-25

Unit Conversions........................................................................... 3-26

Unit Prefixes............................................................................ 3-26

Units of Length ........................................................................ 3-26

Units of Volume....................................................................... 3-26

Units of Mass........................................................................... 3-26

Units of Force.......................................................................... 3-26

Units of Torque........................................................................ 3-26

Units of Pressure..................................................................... 3-26

Units of Power......................................................................... 3-26

Units of Temperature............................................................... 3-26

Periodic Maintenance ......................................................................... 4-1

Safety Precautions .......................................................................... 4-3

Introduction...................................................................................... 4-3

The Importance of Periodic Maintenance.................................. 4-3

Performing Periodic Maintenance ............................................. 4-3

Yanmar Replacement Parts ...................................................... 4-3

Required EPA Maintenance ...................................................... 4-3

EPA Requirements.......................................................................... 4-3

Conditions to Ensure Compliance with

EPA Emission Standards .......................................................... 4-3

Inspection and Maintenance ..................................................... 4-4

Periodic Maintenance Schedule...................................................... 4-5

Periodic Maintenance Procedures .................................................. 4-9

After Initial 50 Hours of Operation............................................. 4-9

Every 50 Hours of Operation................................................... 4-10

Every 250 Hours of Operation................................................. 4-11

Every 500 Hours of Operation................................................. 4-15

Every 1000 Hours of Operation............................................... 4-17

Every 2000 Hours of Operation............................................... 4-17

Engine .................................................................................................. 5-1

Safety Precautions .......................................................................... 5-3

Introduction...................................................................................... 5-3

Specifications .................................................................................. 5-4

General Information................................................................... 5-4

Test and Adjustment Specifications .......................................... 5-4

Repair Specifications................................................................. 5-5

Special Torque Chart ...................................................................... 5-8

Special Service Tools.................................................................... 5-11

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BY Service Manual v

Measuring Instruments.................................................................. 5-12

Sealants and Compounds............................................................. 5-13

Tests and Adjustments.................................................................. 5-14

Test Compression ................................................................... 5-14

Repair............................................................................................ 5-15

Cylinder Head................................................................................ 5-16

Cylinder Head Components .................................................... 5-16

General Guidelines.................................................................. 5-17

Remove and Install Cylinder Head Cover ............................... 5-17

Remove and Install Glow Plugs............................................... 5-19

Remove Cylinder Head ........................................................... 5-19

Disassemble Cylinder Head .................................................... 5-22

Clean Cylinder Head Components.......................................... 5-24

Pressure Test the Cylinder Head ............................................ 5-24

Inspect Cylinder Head Components........................................ 5-24

Replace Valve Stem Seals...................................................... 5-25

Assemble Cylinder Head......................................................... 5-26

Determine Cylinder Head Gasket Thickness........................... 5-26

Install Cylinder Head ............................................................... 5-27

Pistons and Cylinders.................................................................... 5-31

Remove and Disassemble Piston and Connecting Rod.......... 5-31

Inspect Pistons and Piston Rings............................................ 5-32

Assemble Piston and Connecting Rod.................................... 5-33

Install Piston and Connecting Rod .......................................... 5-34

Flywheel and Flywheel Housing.................................................... 5-37

Remove and Install Flywheel Housing ................................... 5-37

Remove and Install Drive Coupling ......................................... 5-38

Remove Flywheel.................................................................... 5-39

Replace Rear Crankshaft Seal................................................ 5-40

Install Flywheel........................................................................ 5-41

Camshaft and Timing Gear Train.................................................. 5-42

Components ............................................................................ 5-42

Check and Adjust Camshaft Timing ........................................ 5-44

Remove and Install Vibration Damper - 4BY2......................... 5-46

Remove and Install Vibration Damper - 6BY2......................... 5-47

Remove Timing Case Cover ................................................... 5-48

Remove and Install Timing Chain............................................ 5-49

Install Timing Case Cover ....................................................... 5-49

Remove and Install Timing Chain Tensioner........................... 5-50

Remove Camshafts................................................................. 5-51

Install Camshafts..................................................................... 5-54

Cylinder Block and Crankshaft...................................................... 5-56

Components ............................................................................ 5-56

Remove Crankshaft................................................................. 5-58

Measure Oil Clearance............................................................ 5-59

Inspect Crankshaft................................................................... 5-61

Inspect Cylinder Block............................................................. 5-62

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vi BY Service Manual

Install Crankshaft..................................................................... 5-62

Replace Front Crankshaft Seal ............................................... 5-64

Intake Manifold.............................................................................. 5-66

Remove................................................................................... 5-66

Install....................................................................................... 5-67

Exhaust Manifold........................................................................... 5-69

Remove................................................................................... 5-69

Install....................................................................................... 5-69

Fuel System......................................................................................... 6-1

Safety Precautions .......................................................................... 6-3

Introduction...................................................................................... 6-3

Specifications .................................................................................. 6-4

Test and Adjustment Specifications .......................................... 6-4

Special Torque Chart ................................................................ 6-4

Special Service Tools...................................................................... 6-5

Fuel System Components............................................................... 6-6

4BY2 Engines............................................................................ 6-6

6BY2 Engines............................................................................ 6-6

Fuel Flow Diagram .......................................................................... 6-7

Tests and Adjustments.................................................................... 6-9

Measure Fuel Feed Pump Pressure ......................................... 6-9

Test Return Fuel Pressure ...................................................... 6-10

Repair............................................................................................ 6-11

Remove Fuel Injector .............................................................. 6-11

Clean Fuel Injector Cavities .................................................... 6-12

Install Fuel Injector .................................................................. 6-13

Remove and Install High-Pressure Fuel Lines ........................ 6-14

Replace the Fuel Feed Pump.................................................. 6-15

Replace High-Pressure Fuel Pump......................................... 6-15

Replace Fuel Filters ................................................................ 6-19

Remove and Install Fuel Rail .................................................. 6-20

Replace Injector Return Fuel Line........................................... 6-21

Bleed the Fuel System ............................................................ 6-22

Cooling System................................................................................... 7-1

Safety Precautions .......................................................................... 7-3

Introduction...................................................................................... 7-4

Specifications .................................................................................. 7-4

Test and Adjustment Specifications .......................................... 7-4

Repair Specifications................................................................. 7-4

Special Torque Chart ................................................................ 7-4

Special Service Tools...................................................................... 7-5

Measuring Instruments.................................................................... 7-5

Cooling Flow Diagram..................................................................... 7-6

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BY Service Manual vii

Tests and Adjustments.................................................................... 7-7

Pressure Test Cooling System and Filler Cap........................... 7-7

Test Thermostat ........................................................................ 7-8

Repair.............................................................................................. 7-8

Drain and Refill Seawater Cooling System................................ 7-8

Check and Replace Anodes...................................................... 7-9

Drain and Fill Closed Cooling System..................................... 7-10

Disconnect and Connect Quick-Connect Fittings.................... 7-11

Remove and Install Hydraulic Oil Cooler................................. 7-11

Inspect and Clean Hydraulic Oil Cooler................................... 7-12

Remove and Install Charge Air Cooler.................................... 7-12

Disassemble and Assemble Charge Air Cooler ...................... 7-13

Remove and Install Heat Exchanger....................................... 7-13

Disassemble and Assemble Heat Exchanger ......................... 7-14

Remove and Install Coolant Pump.......................................... 7-15

Remove and Install Thermostat............................................... 7-16

Seawater Pump....................................................................... 7-18

Lubrication........................................................................................... 8-1

Safety Precautions .......................................................................... 8-3

Introduction...................................................................................... 8-3

Specifications .................................................................................. 8-4

Test and Adjustment Specifications .......................................... 8-4

Special Torque Chart................................................................. 8-4

Special Service Tools...................................................................... 8-5

Measuring instruments .................................................................... 8-5

Tests and Adjustments.................................................................... 8-6

Engine Oil Flow ......................................................................... 8-6

Check Engine Oil Pressure ....................................................... 8-7

Repair.............................................................................................. 8-8

Engine Lubrication System Components .................................. 8-8

Change Engine Oil and Replace Engine Oil Filter Element ...... 8-9

Remove and Install Oil Cooler................................................... 8-9

Remove and Install Oil Filter Housing ..................................... 8-11

Remove and Install Oil Sump.................................................. 8-11

Oil Pump.................................................................................. 8-12

Turbocharger....................................................................................... 9-1

Safety Precautions .......................................................................... 9-3

Introduction...................................................................................... 9-3

Specifications .................................................................................. 9-3

Test and Adjustment Specifications .......................................... 9-3

Special Torque Chart................................................................. 9-3

Special Service Tools...................................................................... 9-4

Sealants and compounds................................................................ 9-4

Tests and Adjustments.................................................................... 9-5

Measure Charge Pressure ........................................................ 9-5

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viii BY Service Manual

Repair.............................................................................................. 9-6

Remove Turbocharger ............................................................. 9-6

Install Turbocharger ................................................................. 9-6

Starter Motor...................................................................................... 10-1

Safety Precautions ........................................................................ 10-3

Introduction.................................................................................... 10-3

Starter Motor Specifications .......................................................... 10-3

General Specifications ............................................................ 10-3

Special Torque Chart .............................................................. 10-3

Starter Motor Troubleshooting....................................................... 10-4

Remove and Install Starter Motor.................................................. 10-5

Alternator........................................................................................... 11-1

Safety Precautions ........................................................................ 11-3

Introduction.................................................................................... 11-4

Specifications ................................................................................ 11-4

General Specifications ............................................................ 11-4

Special Torque Chart .............................................................. 11-4

Repair............................................................................................ 11-5

Replace Alternator Belt ........................................................... 11-5

Remove and Install Alternator................................................. 11-5

Remove and Install Alternator Belt Tensioner......................... 11-6

Electrical and ECU ............................................................................ 12-1

Safety Precautions ........................................................................ 12-3

Introduction.................................................................................... 12-3

Specifications ................................................................................ 12-3

Special Torque Chart .............................................................. 12-3

Function Description - Engine Management System .................... 12-4

Component Locations ............................................................. 12-4

Electrical Panel Connector (X1) Connections ......................... 12-8

Engine Control Unit (ECU) Assignments............................... 12-10

Component Tests........................................................................ 12-12

Relays ................................................................................... 12-12

Oil Pressure Sensor .............................................................. 12-14

Fuel Injector........................................................................... 12-14

Engine Coolant Temperature Sensor.................................... 12-15

High-Pressure Fuel Regulator............................................... 12-15

Water-in-Fuel Sensor ............................................................ 12-16

Crankshaft Speed Sensor ..................................................... 12-16

Glow Plug / Control Unit........................................................ 12-17

Fuel Temperature Sensor ..................................................... 12-18

Fuel Volume Regulator.......................................................... 12-18

Charge Air Temperature Sensor ........................................... 12-19

Charge Air Pressure Sensor ................................................. 12-19

High-Pressure Fuel Rail Pressure Sensor ............................ 12-20

Camshaft Speed Sensor ....................................................... 12-20

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BY Service Manual ix

Throttle Position Sensor ........................................................ 12-21

Repair.......................................................................................... 12-22

Replace Engine Control Unit (ECU) ...................................... 12-22

Replace Coolant Temperature Sensor.................................. 12-22

Replace Charge Air Pressure Sensor ................................... 12-23

Replace Charge Air Temperature Sensor ............................. 12-23

Replace Crankshaft Sensor................................................... 12-24

Replace Camshaft Sensor..................................................... 12-24

Replace High-Pressure Fuel Regulator................................. 12-25

Replace High-Pressure Fuel Rail Pressure Sensor .............. 12-26

Replace Fuel Temperature Sensor ....................................... 12-26

Replace Fuel Volume Regulator............................................ 12-27

Replace Oil Pressure Sensor ................................................ 12-27

Troubleshooting................................................................................ 13-1

Safety Precautions ........................................................................ 13-3

Introduction.................................................................................... 13-3

Engine Faults and Torque Limitations........................................... 13-3

Torque Limitation for Failed Sensors Mode............................. 13-3

Torque Limitation for Smoke Limitation Mode......................... 13-3

Torque Limitation for Overheat Protection Mode..................... 13-5

Troubleshooting Chart................................................................... 13-6

Starting Trouble....................................................................... 13-6

Exhaust Color.......................................................................... 13-6

Vibration - Drive Disengaged................................................... 13-7

Vibration - Drive Engaged ....................................................... 13-7

Engine Knocks......................................................................... 13-8

Low Power Output................................................................... 13-8

Engine Overheat...................................................................... 13-8

Engine Runs Cold.................................................................... 13-9

Coolant Loss............................................................................ 13-9

Helm Panel Display ................................................................. 13-9

Trouble Codes............................................................................. 13-10

Working Procedure................................................................ 13-10

Diagnostic Trouble Codes ..................................................... 13-10

After Troubleshooting or Repair .................................................. 13-14

TABLE OF CONTENTS

xBY Service Manual

This Page Intentionally Left Blank

BY Service Manual 1-1

BY Service Manual Section 1

INTRODUCTION

This manual gives specific instructions for the

proper repair of Yanmar BY2 series marine

engines.

Please follow the procedures carefully to ensure

quality service.

Yanmar recommends that you read this Service

Manual completely before starting repairs.

Along with standard tools, Yanmar recommends the

use of special tools necessary to perform repairs

correctly.

Yanmar products are continuously undergoing

improvement. This Service Manual has been

checked carefully in order to avoid errors. However

Yanmar is not liable for any misrepresentations,

errors of description or omissions. Contact the

regional headquarters for any questions you have

regarding this Service Manual.

INTRODUCTION Revision History

1-2 BY Service Manual

REVISION HISTORY

This manual is a living document. Periodic manual

revisions are published to document product

improvements and changes. This practice ensures

the manual has the most current information.

As manual revisions become necessary, individual

pages are prepared and sent to those who need

the information. If a page, or number of pages

should be replaced, the replacement information is

sent along with a revised Revision Control Table.

Discard the older, obsolete information.

At times, the revision involves inserting additional

pages in one or more sections. Replace the

Revision Control Table and insert the new pages.

This method of revision control represents the most

cost-effective solution to providing current, updated

information as needed.

Revision Control Table

Revision Date

Revision Number

New Page Numbers

Involved Remarks Initiating

Dept.

APR 2009 All Initial release YMI

BY Service Manual 2-1

BY Service Manual Section 2

SAFETY

Yanmar is concerned for your safety and the

condition of your marine engine. Safety statements

are one of the primary ways to call your attention to

the potential hazards associated with Yanmar

Marine engines. Follow the precautions listed

throughout the manual before operation, during

operation and during periodic maintenance

procedures for your safety, the safety of others and

to protect the performance of your marine engine.

Keep the decals from becoming dirty or torn and

replace them if they are lost or damaged. Also, if a

part needs to be replaced that has a decal attached

to it, make sure to order the new part and decal at

the same time.

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.

Indicates a situation which can cause damage to

the engine, personal property and / or the

environment or cause the equipment to operate

improperly.

This safety alert symbol appears

with most safety statements. It

means attention, become alert,

your safety is involved! Please read

and abide by the message that

follows the safety alert symbol.

SAFETY Safety Precautions

2-2 BY Service Manual

SAFETY PRECAUTIONS

There is no substitute for common sense and

careful practices. Improper practices or

carelessness can cause burns, cuts, mutilation,

asphyxiation, other bodily injury or death. This

information contains general safety precautions

and guidelines that must be followed to reduce risk

to personal safety. Special safety precautions are

listed in specific procedures. Read and understand

all of the safety precautions before operating or

performing repairs or maintenance.

The safety messages that follow

have DANGER level hazards.

NEVER permit anyone to install or

operate the engine without proper

training.

• Read and understand this Service Manual before

operating or servicing the engine to ensure that

safe operating practices and maintenance

procedures are followed.

• Safety signs and decals are additional reminders

for safe operating and maintenance techniques.

• Contact your Yanmar RHQ for additional training.

Crush Hazard

When attaching an engine to a repair

stand, be sure to use a stand of

adequate capacity to safely support

the engine to be repaired, and that it

is securely attached to the engine.

NEVER stand under a hoisted engine. If the hoist

mechanism fails, the engine will fall on you.

ALWAYS secure the engine solidly to prevent the

engine from falling during maintenance.

The safety messages that follow have

WARNING level hazards.

Explosion Hazard

While the engine is running or the

battery is charging, hydrogen gas is

being produced and can be easily

ignited. Keep the area around the

battery well-ventilated and keep sparks,

open flame and any other form of ignition out of the

area.

ALWAYS turn off the battery switch (if equipped) or

disconnect the negative (-) battery cable before

servicing the equipment.

Fire and Explosion Hazard

Diesel fuel is flammable and explosive under

certain conditions.

NEVER use a shop rag to catch the fuel.

Wipe up all spills immediately.

NEVER refuel with the engine running.

Store any containers containing fuel in a

well-ventilated area, away from any combustibles or

sources of ignition.

SAFETY

Safety Precautions

12/05

BY Service Manual 2-3

Fire Hazard

Have appropriate safety equipment

available. Have all fire extinguishers

checked periodically for proper operation

and / or readiness.

ALWAYS read and follow safety-related precautions

found on containers of hazardous substances like

parts cleaners, primers, sealants and sealant

removers.

Undersized wiring systems can cause an electrical

fire.

Coolant may be flammable under certain

conditions. NEVER allow coolant to come into

contact with hot surfaces or insulation material.

Entanglement Hazard

NEVER leave the key in the key switch

when servicing the engine. Attach a

“Do Not Operate” tag near the key

switch while performing maintenance

on the equipment.

ALWAYS stop the engine before beginning service.

If the engine must be serviced while it is operating,

remove all jewelry, tie back long hair and keep

hands, other body parts and clothing away from

moving / rotating parts.

Piercing Hazard

Avoid skin contact with high-pressure

diesel fuel spray caused by a fuel system

leak such as a broken fuel injection line.

High-pressure fuel can penetrate your

skin and result in serious injury. If you

are exposed to high-pressure fuel spray, obtain

prompt medical treatment.

NEVER check for a fuel leak with your hands.

ALWAYS use a piece of wood or cardboard.

Flying Object Hazard

ALWAYS wear eye protection when

servicing the engine or when using

compressed air or high-pressure water.

Dust, flying debris, compressed air,

pressurized water or steam may injure

your eyes.

Coolant Hazard

Wear eye protection and rubber gloves

when handling Long Life Coolant (LLC).

If contact with the eyes or skin should

occur, flush eyes and wash immediately with clean

water.

SAFETY Safety Precautions

2-4 BY Service Manual

Sever Hazard

NEVER wear jewelry, unbuttoned cuffs,

ties or loose-fitting clothing and

ALWAYS tie long hair back when

working near moving / rotating parts

such as the flywheel or PTO shaft. Keep hands,

feet and tools away from all moving parts.

The propeller may rotate during towing or if the

engine is running at idle speed. NEVER service the

engine while being towed or when the engine is

running.

If the vessel has more than one engine, NEVER

service an engine if either of the engines is running.

In multi-engine configurations the propeller for an

engine that is shut down may rotate if any of the

other engines are running.

NEVER operate the engine without the guards in

place.

NEVER operate the engine while wearing a

headset to listen to music or radio because it will be

difficult to hear the warning signals.

Electrical Hazard

Make welding repairs safely.

• ALWAYS turn off the battery switch (if

equipped) or disconnect the negative (-)

battery cable and the leads to the

alternator when welding on the

equipment.

• Remove the multi-pin connector to the engine

control unit. Connect the weld clamp to the

component to be welded and as close as possible

to the welding point.

• NEVER connect the weld clamp to the engine or

in a manner which would allow current to pass

through a mounting bracket.

• When welding is complete, reconnect the leads to

the alternator and engine control unit prior to

reconnecting the batteries.

ALWAYS keep the electrical connectors and

terminals clean. Check the electrical harnesses for

cracks, abrasions and damaged or corroded

connectors.

NEVER turn off the battery switch (if equipped) or

short the battery cables during operation. Damage

to the electrical system will result.

Exhaust Hazard

All internal combustion engines create

carbon monoxide gas during operation

and special precautions are required to

avoid carbon monoxide poisoning.

• NEVER block windows, vents or other means of

ventilation if the engine is operating in an

enclosed area.

• ALWAYS ensure that all connections are

tightened to specifications after repair is made to

the exhaust system.

Burn Hazard

Some of the engine surfaces become

very hot during operation and shortly

after shutdown.

• Keep hands and other body parts away from hot

engine surfaces.

• Handle hot components with heat-resistant

gloves.

Sudden Movement Hazard

To prevent accidental equipment movement,

NEVER start the engine in gear.

Shift the marine gear into the NEUTRAL position

any time the engine is at idle.

SAFETY

Safety Precautions

12/05

BY Service Manual 2-5

Lifting Hazard

The engine lifting eyes are engineered to lift the

weight of the marine engine only. ALWAYS use the

engine lifting eyes when lifting the engine.

Additional equipment is necessary to lift the marine

engine and marine gear together. ALWAYS use

lifting equipment with sufficient capacity to lift the

marine engine.

If transport is needed for engine repair, have a

helper assist in attaching it to a hoist and loading it

onto a truck.

Alcohol and Drug Hazard

NEVER operate the engine while under

the influence of alcohol, drugs or when

ill.

Exposure Hazard

ALWAYS wear personal protective

equipment including appropriate

clothing, gloves, work shoes and eye

and hearing protection as required by

the task at hand.

Tool Hazard

ALWAYS remove any tools or shop rags used

during maintenance from the area before operation.

The safety messages that follow have CAUTION

level hazards.

Poor Lighting Hazard

Ensure that the work area is adequately

illuminated. ALWAYS install wire cages on portable

safety lamps.

Tool Hazard

ALWAYS use tools appropriate for the task at hand

and use the correct size tool for loosening or

tightening machine parts.

SAFETY Safety Precautions

2-6 BY Service Manual

The safety messages that follow have NOTICE

level hazards.

Any part which is found defective as a result of

inspection or any part whose measured value does

not satisfy the standard or limit must be replaced.

ALWAYS tighten components to the specified

torque. Loose parts can cause equipment damage

or cause it to operate improperly.

Only use replacement parts specified. Other

replacement parts may affect warranty coverage.

NEVER attempt to modify the engine design or

safety features such as defeating the engine speed

limit control or the diesel fuel injection quantity

control.

Modifications may impair the engine’s safety and

performance characteristics and shorten the

engine’s life. Any alterations to this engine may void

its warranty. Be sure to use Yanmar genuine

replacement parts.

Follow the guidelines of the EPA or

other governmental agencies for the

proper disposal of hazardous materials

such as engine oil, diesel fuel and

engine coolant. Consult the local

authorities or reclamation facility.

NEVER dispose of hazardous materials by

dumping them into a sewer, on the ground or into

groundwater or waterways.

If any indicator illuminates during engine operation,

stop the engine immediately. Determine the cause

and repair the problem before continuing to operate

the engine.

Make sure the engine is installed on a level surface.

If a Yanmar Marine engine is installed at an angle

that exceeds the specifications stated in the

Yanmar Marine Installation Manuals, engine oil may

enter the combustion chamber causing excessive

engine speed, white exhaust smoke and serious

engine damage. This applies to engines that run

continuously or those that run for short periods of

time.

BY Service Manual 3-1

BY Service Manual Section 3

GENERAL SERVICE

INFORMATION