Yanmar 6LPA-STP2 User manual

6LPA
series
6LPA Service Manual
SERVICE MANUAL
6LPA-STP2
6LPA-STZP2
P/N: 0B6LP-G00100
MARINE
ENGINES

26LPA Service Manual
© 2007 Yanmar Marine International
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.
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.
0707

6LPA Service Manual 1
© 2007 Yanmar Marine International
6LPA Service Manual TABLE OF
CONTENTS
Page
Table of
Contents.................................................................................................. iii
Introduction ......................................................................................... 1-1
Safety.................................................................................................... 2-1
General Service Information ............................................................. 3-1
Periodic Maintenance ......................................................................... 4-1
Engine .................................................................................................. 5-1
Fuel System......................................................................................... 6-1
Cooling System................................................................................... 7-1
Lubrication........................................................................................... 8-1
Turbocharger....................................................................................... 9-1
Starter Motor...................................................................................... 10-1
Alternator........................................................................................... 11-1
Troubleshooting................................................................................ 12-1

TABLE OF CONTENTS
26LPA Service Manual
© 2007 Yanmar Marine International
This Page Intentionally Left Blank

6LPA Service Manual 1-1
© 2007 Yanmar Marine International
6LPA Service Manual Section 1
INTRODUCTION
This manual gives specific instructions for the
proper repair of Yanmar 6LPA-STP2/STZP2 series
marine engines.
Please follow the procedures carefully to ensure
quality service.
Yanmar recommends that you read this Service
Manual completely before starting with 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 an
authorized Yanmar marine dealer or distributor for
any questions you have regarding this Service
Manual.

INTRODUCTION
1-2 6LPA Service Manual
Revision History
© 2007 Yanmar Marine International
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.
Jun 2007
Rev. 0 ALL Initial Release YMI

6LPA Service Manual 2-1
© 2007 Yanmar Marine International
6LPA Service Manual Section 2
SAFETY
SAFETY STATEMENTS
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
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.
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.
AThis 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
2-2 6LPA Service Manual
Safety Precautions
© 2007 Yanmar Marine International
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 operation or
performing repairs or maintenance.
The safety messages that follow have DANGER
level hazards. These safety messages describe
a hazardous situation which, if not avoided, will
result in death or serious injury.
NEVER permit anyone to install or
operate the engine without proper
training.
• Read and understand this Service 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.
Crush Hazard
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. These safety
messages describe a hazardous situation
which, if not avoided, could result in death or
serious injury.
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
6LPA Service Manual 2-3
Safety Precautions
12/05
© 2007 Yanmar Marine International
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.
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 you must service the engine while it is operating,
remove all jewelry, tie back long hair and keep your
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. Have
your authorized Yanmar marine dealer or distributor
repair the damage.
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
2-4 6LPA Service Manual
Safety Precautions
© 2007 Yanmar Marine International
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 a engine if either of the engines are
running. In multi-engine configurations the propeller
for an engine that is shut down may rotate if any of
the other engines are running.
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 completed, 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 shut down.
• Keep hands and other body parts away from hot
engine surfaces.
• Handle hot components with heat-resistant
gloves.

SAFETY
6LPA Service Manual 2-5
Safety Precautions
12/05
© 2007 Yanmar Marine International
Sudden Movement 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.
Lifting Hazard
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 you need to transport an engine for repair have a
helper assist you attach it to a hoist and load it on a
truck.
Alcohol and Drug Hazard
NEVER operate the engine while you
are under the influence of alcohol or
drugs or are 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.
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. These safety messages describe
a hazardous situation which, if not avoided,
could result in minor or moderate injury.
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.
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
2-6 6LPA Service Manual
Safety Precautions
© 2007 Yanmar Marine International
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.
NEVER attempt to adjust the low or high idle speed
limit screw. This may impair the safety and
performance of the engine and shorten its life.
Modifications of this type may void the warranty. If
adjustment is ever required, contact your
authorized Yanmar marine dealer or distributor.
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.
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 any indicator illuminates during engine operation,
stop the engine immediately. Determine the cause
and repair the problem before you continue 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.

6LPA Service Manual 3-1
© 2007 Yanmar Marine International
6LPA Service Manual Section 3
GENERAL SERVICE
INFORMATION
Page
Safety Precautions.......................................................................... 3-3
Location of Safety Decals................................................................ 3-3
Component Identification................................................................. 3-4
Engine Piping Diagrams.................................................................. 3-6
6LPA-STP2................................................................................ 3-6
6LPA-STZP2 ............................................................................. 3-8
External Views............................................................................... 3-10
6LPA-STP2.............................................................................. 3-10
Engine Sender and Switch Locations............................................ 3-12
Instrument Panel (Optional) .......................................................... 3-13
B-Type Panel (119773-91131)................................................ 3-13
C-Type Panel (119773-91162)................................................ 3-13
D-Type Panel (119773-91192)................................................ 3-13
Performance Curve Charts............................................................ 3-14
Front Power Take-Off (PTO) Output............................................. 3-16
Front PTO Diagram................................................................. 3-16
Location of Nameplate .................................................................. 3-18
Engine Nameplate (Typical).................................................... 3-18
Diesel Fuel .................................................................................... 3-18
Diesel Fuel Specifications ....................................................... 3-18
Handling Diesel Fuel ............................................................... 3-19
Diesel Fuel Lines..................................................................... 3-19
Fuel Tank................................................................................. 3-20
Filling the Fuel Tank................................................................ 3-20
Bleeding the Fuel System........................................................ 3-21

GENERAL SERVICE INFORMATION
3-2 6LPA Service Manual
© 2007 Yanmar Marine International
Engine Oil....................................................................................... 3-22
Engine Oil Specifications ......................................................... 3-22
Checking the Engine Oil........................................................... 3-23
Adding Engine Oil..................................................................... 3-23
Marine Drive Oil ............................................................................. 3-23
Mercruiser® Bravo Stern Drive Oil Specifications.................... 3-23
Checking and Adding Marine Drive Oil .................................... 3-23
Checking and Adding Power Steering Oil
(6LPA-STZP2 Models)............................................................. 3-24
Engine Coolant............................................................................... 3-24
Engine Coolant Specifications.................................................. 3-24
Checking and Adding Engine Coolant...................................... 3-25
Draining the Freshwater and Seawater Cooling System.......... 3-26
Principal Engine Specifications...................................................... 3-27
Marine Gear (Optional)............................................................. 3-28
Special Torque Chart..................................................................... 3-29
Tightening Torques for Standard Bolts and Nuts........................... 3-30
Tightening Fasteners................................................................ 3-30
Abbreviations and Symbols............................................................ 3-31
Abbreviations............................................................................ 3-31
Symbols.................................................................................... 3-31
Unit Conversions............................................................................ 3-32
Unit Prefixes............................................................................. 3-32
Units of Length......................................................................... 3-32
Units of Volume........................................................................ 3-32
Units of Mass............................................................................ 3-32
Units of Force........................................................................... 3-32
Units of Torque......................................................................... 3-32
Units of Pressure...................................................................... 3-32
Units of Power.......................................................................... 3-32
Units of Temperature................................................................ 3-32
Special Service Tools..................................................................... 3-33
Equipment (Locally Available).................................................. 3-42
Measuring Instruments................................................................... 3-44
Special Service Materials (Locally Available)................................. 3-46
Special Service Materials Reference (Locally Available)......... 3-47
Wiring Diagrams............................................................................. 3-48
B-Type Instrument Panel.......................................................... 3-48
C/D-Type x B-Type Instrument Panel ...................................... 3-49
C/D-Type x C-Type Instrument Panel...................................... 3-50

GENERAL SERVICE INFORMATION
6LPA Service Manual 3-3
Safety Precautions
12/05
© 2007 Yanmar Marine International
SAFETY PRECAUTIONS
Before you service the engine, read the following safety information and review the Safety Section on
page 2-1.
LOCATION OF SAFETY DECALS
Figure 3-1 shows the location of safety decals on Yanmar 6LPA-STP2/STZP2 series marine engines.
Figure 3-1
Figure 3-1
1 –Part Number: 120324-07240
2 –Part Number: 128296-07260
3 –Part Number: 119773-07280
4 –Part Number: 128296–07300
5 –Part Number: 128296–07360
Note: shows an overhead view of the engine.
NEVER pour the
engine oil across
the full line.
119773-07280
DANGER
FULL
LOW
(1) (2) (3) (4)
(5)
0004813

GENERAL SERVICE INFORMATION
3-4 6LPA Service Manual
Component Identification
© 2007 Yanmar Marine International
COMPONENT IDENTIFICATION
Figure 3-2Service Side (Left side as viewed from propeller)
Figure 3-2
1 –Fuel Cooler
2 –Fuel Filter
3 –Power Steering Oil Cooler (6LPA-STZP2
Series Only)
4 –Engine Oil Filter
5 –Intercooler
6 –Mixing Elbow
7 –Engine Oil Cooler (2)
8–Starter
9 –Engine Oil Cooler (1)
10–Fuel Injection Pump
11–Seawater Pump
12–SternDrive
Note: 6LPA-STZP2 Series with stern drive shown
(1)
(2) (3)(4)
(5) (6)
(12)
(11) (10) (9) (8)(7)
0004884

GENERAL SERVICE INFORMATION
6LPA Service Manual 3-5
Component Identification
12/05
© 2007 Yanmar Marine International
Figure 3-3Non-Service Side
Figure 3-3
1 –Turbocharger
2 –Engine Nameplate (on rocker arm cover)
3 –Freshwater Coolant Tank
4 –Power Steering Oil Tank (6LPA-STZP2
Series Only)
5 –Freshwater Filler Cap
6 –Engine Oil Filler Cap
7 –Power Steering Oil Pump (6LPA-STZP2
Series Only)
8–Alternator
9 –Engine Oil Dipstick
10–Freshwater Cooler
11–V-Belt
Note: 6LPA-STZP2 Series with stern drive shown
(1) (2) (3)(4) (5)
(6)
(7)
(8)
(9)
(10)
(11)
0004885

GENERAL SERVICE INFORMATION
3-6 6LPA Service Manual
Engine Piping Diagrams
© 2007 Yanmar Marine International
ENGINE PIPING DIAGRAMS
6LPA-STP2
Figure 3-4
Figure 3-4
-
-
-
(8)
(6)
(5)
(4)
(3)(2)(1)
(9)
(12) (11)
(14)
(13)
(16)
(15)
(18)
(21)
(23)
(25)
(17)
(10)
(19)
(20)
(22)
(24)
(26)
(7)
0004891

GENERAL SERVICE INFORMATION
6LPA Service Manual 3-7
Engine Piping Diagrams
12/05
© 2007 Yanmar Marine International
1 –Freshwater Cooler
2 –Exhaust Manifold
3 –Mixing Elbow
4 –Seawater Outlet
5 –Turbocharger
6 –Fuel Injection Valves
7 –Engine Oil Cooler
8 –Intercooler
9 –Engine Oil Filter
10–Fuel Injection Pump
11–Seawater Inlet
12–Cooling Seawater Pump
13–Fuel Return Pipe (To Fuel Tank)
14–Diesel Fuel Cooler
15–Diesel Fuel Inlet (From Fuel Tank)
16–Diesel Fuel Filter
17–Water Temperature Sender (Optional)
18–Water Temperature Switch
19–Water Outlet to Heater
20–Engine Oil Cooler (Freshwater Cooling
Relief Valves)
21–Safety Valve
22–Cooling Freshwater Pump
23–Engine Oil Pump
24–Engine Oil Inlet Filter
25–Water Inlet From Heater
26–Thermostat

GENERAL SERVICE INFORMATION
3-8 6LPA Service Manual
Engine Piping Diagrams
© 2007 Yanmar Marine International
6LPA-STZP2
Figure 3-5
Figure 3-5
-
-
-
(11)
(9)
(8)
(7)
(6)
(5)
(4)(3)
(1) (2)
(12)
(16) (15)
(18)
(17)
(20)
(19)
(22)
(25)
(27)
(29)
(21)
(14)
(23)
(24)
(26)
(28)
(30)
(13)
(10)
0004892