Yanmar 6LY3-STC User manual

MARINE
ENGINE
6LY3
series
OPERATION MANUAL
6LY3–STC
6LY3–UTC
P/N: 0ALY3–G00200

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 without notice. Yanmar and are
registered trademarks of Yanmar Co., Ltd. in Japan, the United States and / or other
countries.
All Rights Reserved:
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.
© 2008 Yanmar Marine International
0808
ii 6LY3 LDC Operation Manual
© 2008 Yanmar Marine International

TABLE OF
CONTENTS
Page
Introduction......................................................................1
Record of Ownership......................................................2
Safety...............................................................................3
Safety Precautions.........................................................4
General Information .................................................4
Before You Operate .................................................4
During Operation and Maintenance .............................4
Location of Labels..........................................................8
Product Overview..............................................................9
Yanmar 6LY3 Features and Applications.............................9
New Engine Break-In................................................9
Component Identification...............................................11
Service Side......................................................... 11
Non-Service Side .................................................. 12
Nameplate..................................................................13
Function of Major Components........................................14
Electronic Control System (ECS).....................................15
Display................................................................ 16
DC-DC Converter.........................................................21
Items .................................................................. 21
Outline Drawing .................................................... 22
Fuse Replacement Procedure and Checking the Normal
Operation ............................................................ 22
Before You Operate..........................................................23
Diesel Fuel..................................................................23
Diesel Fuel Specifications ....................................... 23
Filling the Fuel Tank ............................................... 26
Bleeding the Fuel System........................................ 26
Engine Oil...................................................................27
Engine Oil Specifications......................................... 27
Engine Oil Viscosity ............................................... 28
6LY3 LDC Operation Manual iii
© 2008 Yanmar Marine International

Checking Engine Oil............................................... 28
Adding Engine Oil.................................................. 28
Selection of Marine Gear Oil .................................... 28
Engine Coolant............................................................29
Filling Heat Exchanger with Engine Coolant................. 30
Engine Operation.............................................................33
Starting the Engine.......................................................35
Before Starting the Engine....................................... 35
To Start the Engine ................................................ 35
If the Engine Fails to Start........................................ 36
After the Engine has Started .................................... 36
Shifting................................................................ 37
Neutral ................................................................ 37
Ahead................................................................. 37
Astern ................................................................. 37
Cautions During Operation.............................................38
Shutting Down the Engine..............................................40
Normal Shutdown.................................................. 40
Checking the Engine After Operation................................41
Periodic Maintenance.......................................................43
Safety Precautions.......................................................43
Precautions.................................................................45
The Importance of Periodic Maintenance .................... 45
Performing Periodic Maintenance ............................. 45
The Importance of Daily Checks ............................... 45
Keep a Log of Engine Hours and Daily Checks............. 45
Yanmar Replacement Parts ..................................... 45
Tools Required ..................................................... 45
Ask Your Authorized Yanmar Marine Dealer for Help ..... 45
Required EPA Maintenance - USA Only ..................... 45
EPA Installation Requirements - USA Only .................. 46
Tightening Fasteners.............................................. 46
Periodic Maintenance Schedule......................................47
Inspection and Maintenance of EPA Emission-Related
Parts................................................................... 49
Periodic Maintenance Procedures....................................50
Daily Checks ........................................................ 50
After Initial 50 Hours of Operation.............................. 51
Every 50 Hours of Operation .................................... 53
Every 250 Hours of Operation .................................. 57
Every 500 Hours of Operation .................................. 60
Every 1000 Hours of Operation................................. 60
Every 2000 Hours of Operation................................. 61
EPA Requirements.......................................................62
EPA Certification Plates .......................................... 62
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Conditions to Ensure Compliance with EPA Emission
Standards............................................................ 63
Inspection and Maintenance .................................... 63
Troubleshooting..............................................................65
Troubleshooting After Starting.........................................65
Troubleshooting Information........................................... 66
Troubleshooting Chart...................................................67
Long-Term Storage..........................................................69
Before You Place the Engine in Long-Term Storage.............69
Returning the Engine to Service.......................................70
Specifications..................................................................71
Principal Engine Specifications........................................71
Wiring Diagrams.................................................... 73
EPA Warranty USA Only....................................................77
Yanmar Co., Ltd. Limited Emission Control System Warranty
- USA Only..................................................................77
Your Warranty Rights and Obligations: ....................... 78
Warranty Period: ................................................... 78
Warranty Coverage: ............................................... 79
Exclusions: .......................................................... 79
Owner’s Responsibility: .......................................... 79
Customer Assistance: ............................................ 79
Maintenance Log................................................... 80
TABLE OF CONTENTS
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© 2008 Yanmar Marine International

This Page Intentionally Left Blank
TABLE OF CONTENTS
vi 6LY3 LDC Operation Manual
© 2008 Yanmar Marine International

INTRODUCTION
Welcome to the world of Yanmar Marine!
Yanmar Marine offers engines, drive
systems and accessories for all types of
boats, from runabouts to sailboats, and from
cruisers to mega yachts. In marine light duty
commercial boating, the worldwide
reputation of Yanmar Marine is second to
none. We design our engines to respect
nature. This means quieter engines, with
minimal vibrations, cleaner than ever. All of
our engines designed after 1996 meet most
of the present and future emission
regulations, like BSO II, SAV, EPA II, IMO
and RCD.
To help you enjoy your Yanmar 6LY3 engine
for many years to come, please follow these
recommendations:
• Read and understand this Operation
Manual before you operate the machine to
ensure that you follow safe operating
practices and maintenance procedures.
• Keep this Operation Manual in a
convenient place for easy access.
• If this Operation Manual is lost or
damaged, order a new one from your
authorized Yanmar Marine dealer or
distributor.
• Make sure this manual is transferred to
subsequent owners. This manual should
be considered a permanent part of the
engine and remain with it.
• Constant efforts are made to improve the
quality and performance of Yanmar
products, so some details included in this
Operation Manual may differ slightly from
your engine. If you have any questions
about these differences, please contact
your authorized Yanmar Marine dealer or
distributor.
• The specifications and components
(instrument panel, fuel tank, etc.)
described in this manual may differ from
ones installed on your vessel. Please refer
to the manual provided by the
manufacturer of these components.
• Refer to the Yanmar Limited Warranty
Handbook for a complete warranty
description.
6LY3 LDC Operation Manual 1
© 2008 Yanmar Marine International

RECORD OF OWNERSHIP
Take a few moments to record the information you need when you contact Yanmar for
service, parts or literature.
Engine Model:
Engine Serial No.:
Date Purchased:
Dealer:
Dealer Phone:
INTRODUCTION
26LY3 LDC Operation Manual
© 2008 Yanmar Marine International

SAFETY
Yanmar considers safety of great
importance and recommends that anyone
that comes into close contact with its
products, such as those that install, operate,
maintain or service Yanmar products,
exercise care, common sense and comply
with the safety information in this manual
and on the machine’s safety labels. Keep
the labels from becoming dirty or torn and
replace them if they are lost or damaged.
Also, if you need to replace a part that has a
label attached to it, make sure you order the
new part and label at the same time.
!
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.
DANGER
Indicates an hazardous situation which, if
not avoided, will result in death or serious
injury.
WARNING
Indicates a hazardous situation which, if not
avoided, could result in death or serious
injury.
CAUTION
Indicates a hazardous situation which, if not
avoided, could result in minor or moderate
injury.
NOTICE
Indicates a situation which can cause
damage to the engine, personal property
and / or the environment or cause the
equipment to operate improperly.
6LY3 LDC Operation Manual 3
© 2008 Yanmar Marine International

SAFETY PRECAUTIONS
General Information
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 operation
or performing repairs or maintenance.
Before You Operate
DANGER
The safety messages that follow have
WARNING level hazards.
NEVER permit anyone to install or
operate the engine without proper
training.
• Read and understand this Operation
Manual before you operate or service the
engine to ensure that you follow safe
operating practices and maintenance
procedures.
• Safety signs and labels are additional
reminders for safe operating and
maintenance techniques.
• See your authorized Yanmar Marine
dealer or distributor for additional training.
During Operation and
Maintenance
DANGER
The safety message that follows has
DANGER level hazards.
Crush Hazard
NEVER stand under hoisted
engine. If the hoist
mechanism fails, the engine
will fall on you.
SAFETY
46LY3 LDC Operation Manual
© 2008 Yanmar Marine International

WARNING
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 flames and any other form of ignition
out of the area.
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.
NEVER use diesel fuel as a cleaning agent.
Store any containers containing fuel in a
well-ventilated area, away from any
combustibles or sources of ignition.
Fire Hazard
Undersized wiring systems
can cause an electrical fire.
Store any equipment in a designated area
away from moving parts.
NEVER use the engine compartment for
storage.
Sever Hazard
Rotating parts can cause
severe injury or death.
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.
Alcohol and Drug Hazard
NEVER operate the engine
while under the influence of
alcohol or drugs or feeling ill.
Exposure Hazard
ALWAYS wear personal
protective equipment
including appropriate
clothing, gloves, work shoes,
eye and hearing protection as
required by the task at hand.
Entanglement Hazard
NEVER leave the key in the
key switch when you are
servicing the engine.
Someone may accidentally
start the engine and not
realize you are servicing it.
NEVER operate the engine while wearing a
headset to listen to music or radio because
it will be difficult to hear the warning signals.
SAFETY
6LY3 LDC Operation Manual 5
© 2008 Yanmar Marine International

WARNING
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. Have your authorized Yanmar
Marine dealer or distributor repair the
damage.
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.
Sudden Movement Hazard
ALWAYS stop the engine before beginning
service.
Exhaust Hazard
NEVER block windows, vents
or other means of ventilation if
the engine is operating in an
enclosed area. All internal
combustion engines create
carbon monoxide gas during operation and
special precautions are required to avoid
carbon monoxide poisoning.
CAUTION
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.
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 you
handle Long Life engine
coolant. If contact with the
eyes or skin should occur,
flush eyes and wash immediately with clean
water.
SAFETY
66LY3 LDC Operation Manual
© 2008 Yanmar Marine International

NOTICE
The safety messages that follow have
NOTICE level hazards.
It is important to perform daily checks as
listed in the Operation Manual. Periodic
maintenance prevents unexpected
downtime, reduces the number of accidents
due to poor engine performance and helps
extend the life of the engine.
See your authorized Yanmar Marine dealer
or distributor if you need to operate the
engine at high altitudes. At high altitudes the
engine will lose power, run rough and
produce exhaust gases that exceed the
design specifications.
ALWAYS be environmentally
responsible.
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 ground water or waterways.
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.
If you have an installation with two or three
engines and only one engine is operating,
the water pickup (thru-hull) of the non-
running engine(s) should be closed. This will
prevent water from being forced past the
seawater pump and eventually finding its
way into the engine. The result of water
entering the engine could cause seizure or
other serious problems.
If you have an installation with two or three
engines, and only one engine is operating,
please note that if the propeller shaft thru-
hull (stuffing box) is lubricated by engine
water pressure and the engines are
interconnected, care must be taken that
water from the running engine does not
enter the exhaust of the non-running
engine(s). This water could cause seizure of
the non-running engine(s). See your
authorized Yanmar Marine dealer or
distributor for a complete explanation of this
condition.
If you have an installation with two or three
engines, and only one engine is operating,
it is important to limit the amount of throttle
applied to the running engine. If you observe
black smoke or movement of the throttle
does not increase engine rpm, you are
overloading the engine that is running.
Immediately throttle back to approximately
2/3 throttle or to a setting where the engine
performs normally. Failure to do so may
cause the running engine to overheat or
cause excess carbon buildup which may
shorten the engine’s life.
SAFETY
6LY3 LDC Operation Manual 7
© 2008 Yanmar Marine International

LOCATION OF LABELS
Figure 1 shows the location of regulatory
and safety labels on Yanmar 6LY3 series
engines. Please replace if damaged or lost.
0002079
(5)
(1) (2)
(1)
(4)
(3)
Figure 1
1–Part Number: 128296-07300
2–Part Number: 120324-07240
3–Part Number: 128296-07260
4–Part Number: 128296-07350
5–Part Number: 119578-07890
128296-07300
120324-07240
128296-07260
128296-07350
119578-07890
DO NOT STEP
ON COVERS.
POSSIBILITY
OF A FALL
SAFETY
86LY3 LDC Operation Manual
© 2008 Yanmar Marine International

PRODUCT OVERVIEW
YANMAR 6LY3 FEATURES
AND APPLICATIONS
The engine is equipped with a marine gear.
The marine gear output shaft connects with
the propeller shaft. In order to obtain full
performance from your engine, it is
imperative that you check the size and
structure of the hull and use a propeller of
the appropriate size. As new boats are used,
owners add additional equipment and
completely fill the fuel and water tanks,
adding to the overall displacement (weight)
of the vessel. Extra canvas enclosures,
bottom paint and bottom fouling can add
additional hull resistance. It is
recommended that a new vessel be
propped so the engine operates at 95% load
at 3300 rpm. Failure to do so can lead to
reduced vessel performance, lead to
increased smoke levels and cause
permanent damage to your engine.
The engine must be installed correctly with
the seawater or cooling water piping,
exhaust gas piping and electrical wiring. Any
auxiliary equipment attached to the engine
should be easy to use and accessible for
service. To handle the drive equipment,
propulsion systems (including the propeller)
and other onboard equipment, be sure to
observe the instructions and cautions given
in the operation manuals supplied by the
shipyard and equipment manufacturers.
The laws of some countries may require hull
and engine inspections, depending on the
use, size and cruising area of the boat. The
installation, fitting and surveying of this
engine all require specialized knowledge
and engineering skills. See Yanmar’s local
subsidiary in your region or your authorized
Yanmar Marine dealer or distributor.
This engine is designed for light duty
commercial applications. The engine is
designed to be operated at maximum
throttle (3300 rpm) for less than 5% of its
total operation time (30 minutes out of every
10 hours). The engine should be operated
at cruising speed (3200 rpm) for less than
90% of its total operation time (9 hours out
of every 10 hours).
New Engine Break-In
As with all reciprocating engines, the way
your engine is operated during its first 50
hours of operation plays a very significant
role in determining how long it will last and
how well the engine will perform over its
lifetime.
A new Yanmar diesel engine must be
operated at suitable speeds and power
settings during the break-in period to make
the sliding parts, such as piston rings, break
in properly and to stabilize engine
combustion.
During the break-in period, the engine
coolant temperature gauge should be
monitored; temperature should be between
71 and 87C (160 and 190F).
6LY3 LDC Operation Manual 9
© 2008 Yanmar Marine International

During the first 10 hours of operation, the
engine should be run at maximum rpm
minus 400 - 500 rpm (approximately
60 - 70% of load) most of the time. This will
ensure the sliding parts break in properly.
During this period, avoid operating at
maximum engine speed and load to avoid
damaging or scoring sliding parts.
NOTICE: Do not operate at WOT (wide open
throttle) for more than a minute at a time
during the first 10 hours of operation.
Do not operate the engine at low idle or at
low speed and light load for more than
30 minutes at a time. Since unburned fuel
and engine oil will adhere to the piston rings
when operating at low speeds for long
periods, this will interfere with proper
movement of the rings and the lube oil
consumption may increase. Low idle speed
does not allow break-in of sliding parts.
If operating engine at low speed and light
load, you must race the engine to clean the
carbon from the cylinders and fuel injection
valve.
Perform this procedure in open waters:
• With the clutch in NEUTRAL, accelerate
from the low speed position to the high
speed position briefly.
• Repeat this process five times.
Once past the initial 10 hours until 50 hours,
the engine should be used over its full
operating range, with special emphasis on
running at relatively high power settings.
This is not the time for an extended cruise at
idle or low speed. The boat should be run at
maximum speed minus 400 rpm most of the
time (approximately 70% load), with a 10
minute run at maximum minus 200 - 300 rpm
(approximately 80% load) every 30 minutes
and a 4 - 5 minute period of operation at
WOT (wide open throttle) once each 30
minutes. During this period, be sure not to
operate your engine at low speed and light
load for more than 30 minutes. If operating
engine at low speed and light load by
necessity, just after the low idle operation,
be sure to race the engine.
To complete engine break-in, perform After
Initial 50 Hours maintenance procedures.
See Periodic Maintenance Schedule on
page 47.
PRODUCT OVERVIEW
10 6LY3 LDC Operation Manual
© 2008 Yanmar Marine International

COMPONENT IDENTIFICATION
Service Side
(1) (3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
0002020
(2)
Figure 1
1 – Oil Fill Cap
2–Coolant Fill Cap
3–Electronic Control Unit Cover
Plate
4–Fuel Injection Pump
5–Lube Oil Cooler
6–Lube Oil Filter
7–Inter-Cooler
8–Flywheel
9–Air Intake Silencer
10–Turbocharger
PRODUCT OVERVIEW
6LY3 LDC Operation Manual 11
© 2008 Yanmar Marine International

Non-Service Side
0002021
(4)
(1)
(3)
(5)
(2)
(6)
(7)
(8)
Figure 2
1 – Coolant Tank (Exhaust Manifold)
2–Dipstick
3–Freshwater Cooler
4–Seawater Pump
5–Alternator
6–V-Belt
7–Fuel Filter
8–Freshwater Pump
PRODUCT OVERVIEW
12 6LY3 LDC Operation Manual
© 2008 Yanmar Marine International

NAMEPLATE
The engine nameplate and its typical
location is shown in Figure 3. Replace if
damaged or lost. Check the engine model,
output, rpm and serial number on the
nameplate.
0006472
/
Gear Model
ENG.No.
/
Model
min-1
min-1
min-1
Continuous power kW
Speed of prop,shaf t
Fuel stop power kW
Figure 3
PRODUCT OVERVIEW
6LY3 LDC Operation Manual 13
© 2008 Yanmar Marine International

FUNCTION OF MAJOR COMPONENTS
Name of Component Function
Fuel Filter
Removes dirt and water from the fuel. Drain the filter periodically. The filter element
should be replaced periodically. See Replace the Fuel Filter Element on page
51.
Fuel Feed Pump Pumps fuel from tank to the fuel injection pump. Equipped with built-in centrifugal
vane.
Engine Oil Fill Port The fill port used to add engine lubricating oil.
Lubricating Oil Filter (at
full-flow and bypass
sides)
Filters fine metal fragments and carbon from the lubricating oil. Filtered lube oil is
distributed to the engine’s moving parts.
Cooling Water System
There are two cooling systems: freshwater and seawater. The engine’s combus-
tion heat is cooled by the fresh water / coolant in a closed circuit. The fresh water
is cooled by seawater using heat exchanger. The seawater also cools the lube oil
of engine / marine gear and also intake air through coolers in an open circuit.
Freshwater Cooler The freshwater cooler is a heat exchanger to cool the fresh water by using sea-
water.
Freshwater Pump The centrifugal water pump circulates fresh cooling water inside the engine. The
fresh water pump is driven by V-belt.
Seawater Pump The rubber impeller type pump raises seawater for cooling. Never operate it with-
out seawater, as this will damage the impeller.
Freshwater / Coolant Fill
Cap
The fill cap on the coolant tank covers the water supply port. The cap has a pres-
sure regulating valve. When the cooling water temperature rises, the pressure
rises inside the freshwater system.
Coolant Recovery Tank
The pressure regulating valve releases vapor and hot water overflow to the coolant
recovery tank. When the engine stops and the cooling water cools, the pressure
in the cooling water tank also drops very low. The fill cap valve then opens to send
water back from the coolant recovery tank. This minimizes cooling water con-
sumption. Freshwater / coolant level can easily be checked and refilled in this tank.
Oil Cooler This heat exchanger cools high temperature lube oil with seawater.
Turbocharger
The pressurized intake air feeding device: the exhaust gas turbine is rotated by
the exhaust gas, and the power is used to rotate the blower. This pressurizes the
intake air for sending to the cylinder.
Inter-Cooler This heat exchanger cools the pressurized intake air from the turbocharger with
seawater.
Anti-Corrosion Zinc
Anode
The metal area of the seawater cooling system is prone to electrical corrosion. The
anti-corrosion zinc anode is installed in the oil cooler, aftercooler, etc. to prevent
this. The anti-corrosion zinc anode is itself reduced over time by electrical corro-
sion, so it must be replaced at fixed intervals before it is completely consumed in
order to ensure that the metal area of the seawater cooling system remains fully
protected.
Nameplates Nameplates are provided on the engine and the marine gear and include the mod-
el, serial number and other data.
Starter Starter motor for the engine. Powered by the battery.
Alternator Driven by V-belt and generates electricity and charges the battery.
PRODUCT OVERVIEW
14 6LY3 LDC Operation Manual
© 2008 Yanmar Marine International