Yanmar 2YM15 User manual

YM
series
OPERATION MANUAL
2YM15
3YM20
3YM30
P/N: 0AYMM-G00100
MARINE
ENGINES

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.
© 2007 Yanmar Marine International
0907
ii YM Series Operation Manual
© 2007 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 Safety Decals ........................................ 8
Product Overview ...................................................... 9
Yanmar YM Features and Applications ....................... 9
New Engine Break-In ...................................... 10
Component Identification ........................................ 11
Service Side - 2YM15 ..................................... 11
Non-Service Side - 2YM15 ............................... 11
Service Side - 3YM20 ..................................... 12
Non-Service Side - 3YM20 ............................... 12
Service Side - 3YM30 ..................................... 13
Non-Service Side - 3YM30 ............................... 13
Location of Nameplates .......................................... 14
Function of Major Components ................................ 15
Control Equipment ................................................ 16
Instrument Panel (Optional) .............................. 16
Single-Lever Remote Control Handle .................. 19
Before You Operate .................................................. 21
Diesel Fuel .......................................................... 21
Diesel Fuel Specifications ................................ 21
Filling the Fuel Tank ........................................ 24
Bleeding the Fuel System ................................ 25
YM Series Operation Manual iii
© 2007 Yanmar Marine International

Engine Oil ........................................................... 26
Engine Oil Specifications ................................. 26
Engine Oil Viscosity ........................................ 26
Checking the Engine Oil .................................. 27
Adding Engine Oil .......................................... 27
Marine Gear or Sail Drive Oil ................................... 28
Marine Gear Oil Specifications .......................... 28
Sail Drive Oil Specifications - SD20 .................... 28
Checking Marine Gear Oil ................................ 28
Adding Marine Gear Oil ................................... 29
Checking and Adding Sail Drive Oil .................... 29
Engine Coolant ..................................................... 29
Engine Coolant Specifications ........................... 29
Checking and Adding Coolant ........................... 30
Cranking the Engine .............................................. 32
Daily Checks ....................................................... 33
Visual Checks ............................................... 33
Checking Diesel Fuel, Engine Oil and Engine
Coolant Levels .............................................. 34
Checking and Refilling Marine Gear Oil ............... 34
Checking the Battery Electrolyte Level ................ 34
Checking the Alternator Belt ............................ 34
Checking the Remote Control Handle ................. 34
Checking the Alarm Indicators ........................... 34
Preparing Fuel, Oil and Coolant in Reserve .......... 34
Engine Operation ...................................................... 35
Starting the Engine ................................................ 36
Restarting After Starting Failure ......................... 37
Starting at Low Temperatures ........................... 37
After the Engine Has Started ............................. 38
Remote Control Handle Operation ............................ 39
Acceleration and Deceleration .......................... 39
Shifting the Engine ......................................... 39
Shutting Down the Engine ....................................... 40
Emergency 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
TABLE OF CONTENTS
iv YM Series Operation Manual
© 2007 Yanmar Marine International

Keep a Log of Engine Hours and Daily Checks ..... 45
Yanmar Replacement Parts .............................. 45
Tools Required .............................................. 45
Ask Your Authorized Yanmar Marine Dealer or
Distributor For Help ........................................ 45
Tightening Fasteners ...................................... 46
EPA Maintenance Requirements .............................. 47
EPA Requirements for USA and Other Applicable
Countries ..................................................... 47
Conditions to Ensure Compliance with EPA
Emission Standards ........................................ 47
Inspection and Maintenance ............................. 47
Periodic Maintenance Schedule ............................... 48
Inspection and Maintenance of EPA Emission-
Related Parts ................................................ 51
Periodic Maintenance Procedures ............................ 52
After Initial 50 Hours of Operation ...................... 52
Every 50 Hours of Operation ............................. 56
Every 100 Hours of Operation ........................... 58
Every 150 Hours of Operation ........................... 59
Every 250 Hours of Operation ........................... 59
Every 1000 Hours of Operation ......................... 62
Troubleshooting ....................................................... 65
Troubleshooting After Starting ................................. 65
Troubleshooting Information ............................. 66
Troubleshooting Chart ........................................... 67
Long-Term Storage ................................................... 71
Prepare Engine for Long-Term Storage ...................... 71
Draining the Cooling System ................................... 72
Specifications .......................................................... 75
Principal Engine Specifications ................................ 75
2YM15 Engine Specifications ........................... 75
3YM20 Engine Specifications ........................... 77
3YM30 Engine Specifications ........................... 79
Marine Gear and Sail Drive Specifications ........... 81
System Diagrams ..................................................... 83
Piping Diagrams ................................................... 83
Wiring Diagrams ................................................... 88
Emission System Warranty ........................................ 91
Non-Road Emission System Warranty ....................... 91
TABLE OF CONTENTS
YM Series Operation Manual v
© 2007 Yanmar Marine International

Yanmar Co., Ltd. Limited Emission Control
System Warranty - USA Only ............................ 91
Maintenance Log ........................................... 94
TABLE OF CONTENTS
vi YM Series Operation Manual
© 2007 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 leisure
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 meet
applicable regulations, including emissions,
at the time of manufacture.
To help you enjoy your Yanmar YM series
engine for many years to come, please
follow these recommendations:
• Read and understand this Operation
Manual before you operate the engine 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.
YM Series Operation Manual 1
© 2007 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
2YM Series Operation Manual
© 2007 Yanmar Marine International

SAFETY
Yanmar considers safety of great
importance and recommends that anyone
who comes in close contact with its
products, such as those who install,
operate, maintain or service Yanmar
products, exercise care, common sense
and comply with the safety information in
this manual and on the engine’s safety
decals. Keep the decals 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 decal attached to it, make
sure you order the new part and decal 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 a 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.
YM Series Operation Manual 3
© 2007 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 decals 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 a hoisted
engine. If the hoist mechanism
fails, the engine will fall on you.
Fire Hazard
Ensure that appropriate fire
detection and extinguishing
equipment are installed and
checked periodically for
proper operation.
SAFETY
4YM Series Operation Manual
© 2007 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.
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.
Sever Hazard
NEVER wear jewelry,
unbuttoned cuffs, ties or
loose-fitting clothing and
ALWAYS tie back long hair
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 if you are
feeling ill.
Exposure Hazard
ALWAYS wear personal
protective equipment
including appropriate
clothing, gloves, work shoes,
eye and hearing protection as
required for the task at hand.
Sudden Movement Hazard
ALWAYS stop the engine before beginning
service.
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.
Stop the engine before you begin to service
it.
SAFETY
YM Series Operation Manual 5
© 2007 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.
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 engine 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
6YM Series Operation Manual
© 2007 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 seacock of the non-running engine(s)
should be closed. This will prevent water
from being forced past the seawater pump
and entering the engine. The result of water
entering the engine could cause engine
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
two-thirds 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
YM Series Operation Manual 7
© 2007 Yanmar Marine International

LOCATION OF SAFETY DECALS
Figure 1 shows the location of safety decals on Yanmar YM series marine engines.
YM Engines
196630-12980
(1)
(2)
(3)
0004780
WARNING
DANGER
Figure 1
1 – Part Number: 128377–07260
2 – Part Number: 128377–07350
3 – Part Number: 196630–12980
SAFETY
8YM Series Operation Manual
© 2007 Yanmar Marine International

PRODUCT OVERVIEW
YANMAR YM FEATURES
AND APPLICATIONS
The YM series are four-stroke direct
injection diesel engines equipped with liquid
coolant systems.
The 2YM15 is a 2-cylinder engine and is
naturally aspirated.
The 3YM20 is a 3-cylinder engine and is
naturally aspirated.
The 3YM30 is a 3-cylinder engine and is
naturally aspirated.
These engines are equipped with a marine
gear or sail drive unit.
These engines are designed for pleasure
craft use.
It is recommended that new vessels be
propped so the engines can operate at
100 - 200 rpm above the Maximum Rated
Power Output rpm (3700 - 3800) to allow for
some added weight and hull resistance. The
engine must be able to reach the Maximum
Rated Power rpm (3600) under full load at
all times.
Failure to do so can lead to reduced vessel
performance, increased smoke levels and
can cause permanent damage to your
engine, which is not covered by warranty.
The engine must be installed correctly with
coolant lines, exhaust gas lines 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, always observe the instructions
and cautions given in the operation manuals
supplied by the shipyard and equipment
manufacturers.
The YM series engines are designed to be
operated at maximum throttle (3600 rpm) for
less than 5% of total engine time (30 minutes
out of every 10 hours) and cruising speed
(3400 rpm or less) for less than 90% of total
engine time (9 hours out of every 10 hours).
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.
YM Series Operation Manual 9
© 2007 Yanmar Marine International

New Engine Break-In
As with all reciprocating engines, the way
the engine is operated during its first 50
hours of operation plays a 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 allow
the sliding parts, such as piston rings, to
break in properly and to stabilize engine
combustion.
During the break-in period, the engine
coolant temperature gauge should be
monitored. The temperature should be
between 71˚ and 87˚C (160˚ and 190˚F).
During the first 10 hours of operation, the
engine should be operated at maximum rpm
minus 400 to 500 rpm (approximately 60 to
70% of load) most of the time. This will
ensure the sliding parts break in properly.
NOTICE: During this period, avoid
operating at maximum engine speed
and load to avoid damaging or scoring
sliding parts.
NOTICE: NEVER 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 diesel fuel
consumption may increase. Low idle speed
does not allow break-in of sliding parts.
If operating the engine at low speed and light
load, you must race the engine to clean the
carbon from the cylinders and the 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
operated at maximum speed minus 400 rpm
most of the time (approximately 70% load),
with a 10 minute run at maximum minus 200
rpm (approximately 80% load) every
30 minutes and a 4 to 5 minute period of
operation at WOT (wide open throttle) once
every 30 minutes. During this period, be sure
not to operate the engine at low speed and
light load for more than 30 minutes. If
operating engine at low speed and light load
is necessary, race the engine after low idle
operation.
To complete engine break-in, perform After
Initial 50 Hours maintenance procedures.
See After Initial 50 Hours of Operation on
page 52.
PRODUCT OVERVIEW
10 YM Series Operation Manual
© 2007 Yanmar Marine International

COMPONENT
IDENTIFICATION
Service Side - 2YM15
Figure 1 and Figure 2 illustrate a typical
version of a 2YM15 engine. Your engine
may have different equipment from that
illustrated.
(1) (2) (3)
(4)
(5)
(6)
(7)
(8)
(9) 0004781
Figure 1
1 – Intake Silencer (Air Cleaner)
2 – Intake Manifold
3 – Fuel Filter
4 – Fuel Injection Pump
5 – Engine Oil Dipstick
6 – Engine Oil Filler Cap
7 – Fuel Feed Pump
8 – Engine Oil Filter
9 – Marine Gear
Non-Service Side - 2YM15
(1)
(2) (4)
(5)
(7)
(6)
(8)
(3)
0004782
Figure 2
1 – Seawater Pump
2 – Coolant Filler Cap
3 – Engine Nameplate (On Rocker Arm
Cover)
4 – Coolant Tank / Heat Exchanger
5 – Exhaust Manifold
6 – Starter Motor
7 – Shift Lever
8 – Alternator
PRODUCT OVERVIEW
YM Series Operation Manual 11
© 2007 Yanmar Marine International

Service Side - 3YM20
Figure 3 and Figure 4 illustrate a typical
version of a 3YM20 engine. Your engine
may have different equipment from that
illustrated.
(1) (2) (3)
(4)
(5)
(6)
(7)
(8)
(9) 0004783
Figure 3
1 – Intake Silencer (Air Cleaner)
2 – Intake Manifold
3 – Fuel Filter
4 – Fuel Injection Pump
5 – Engine Oil Dipstick
6 – Engine Oil Filler Cap
7 – Fuel Feed Pump
8 – Engine Oil Filter
9 – Marine Gear
Non-Service Side - 3YM20
(1)
(2) (3)
(4)
(5)
(6)
(7)
(8)
0004784
Figure 4
1 – Seawater Pump
2 – Coolant Filler Cap
3 – Engine Nameplate (On Rocker Arm
Cover)
4 – Coolant Tank / Heat Exchanger
5 – Exhaust Manifold
6 – Starter Motor
7 – Shift Lever
8 – Alternator
PRODUCT OVERVIEW
12 YM Series Operation Manual
© 2007 Yanmar Marine International

Service Side - 3YM30
Figure 5 and Figure 6 illustrate a typical
version of a 3YM30 engine. Your engine
may have different equipment from that
illustrated.
(1) (2)
(4)
(5)
(6)
(7)
(8)
(9)
(3)
0004785
Figure 5
1 – Intake Silencer (Air Cleaner)
2 – Intake Manifold
3 – Fuel Filter
4 – Fuel Injection Pump
5 – Engine Oil Dipstick
6 – Engine Oil Filler Cap
7 – Fuel Feed Pump
8 – Engine Oil Filter
9 – Marine Gear
Non-Service Side - 3YM30
(1)
(2) (3)
(4)
(5)
(6)
(7)
(8) 0004786
Figure 6
1 – Seawater Pump
2 – Coolant Filler Cap
3 – Engine Nameplate (On Rocker Arm
Cover)
4 – Coolant Tank / Heat Exchanger
5 – Exhaust Manifold
6 – Starter Motor
7 – Shift Lever
8 – Alternator
PRODUCT OVERVIEW
YM Series Operation Manual 13
© 2007 Yanmar Marine International

LOCATION OF
NAMEPLATES
The nameplate of the Yanmar YM series
engine is shown in Figure 7. Check the
engine's model, output, rpm and serial
number on the nameplate. Replace it if it is
damaged or lost.
The engine nameplate is attached to the
engine rocker arm cover.
0005472
Figure 7
The marine gear nameplate (Figure 8) is
attached to the marine gear. Check the
marine gear's model, gear ratio, oil used, oil
quantity and serial number
MODE L KM
GEAR R ATIO
OI L SAE 20 /30 HD
OI L QT Y. LTR.
NO.
0004529
Figure 8
PRODUCT OVERVIEW
14 YM Series Operation Manual
© 2007 Yanmar Marine International