4BY2_6BY2_SM.book

BY series SERVICE MANUAL BY Service Manual 4BY2 6BY2 P/N: 0BBY0-U00200 MARINE ENGINES

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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. © 2009 Yanmar Marine International 0409 ii BY Service Manual © 2009 Yanmar Marine International

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Table of Contents

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 BY Service Manual iii © 2009 Yanmar Marine International

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Table of Contents

TABLE OF CONTENTS 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 iv BY Service Manual © 2009 Yanmar Marine International

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