50G, 60F, 70B,
This manual has been prepared by the Yamaha Motor Company Ltd. primarily for use by
Yamaha dealers and their trained mechanics when performing maintenance procedures and
repairs to Yamaha equipment. It has been written to suit the needs of persons who have a
basic understanding of the mechanical and electrical concepts and procedures inherent in the
work, for without such knowledge attempted repairs or service to the equipment could render
it unsafe or unfit for use.
Because the Yamaha Motor Company Ltd. has a policy of continuously improving its prod-
ucts, models may differ in detail from the descriptions and illustrations given in this publica-
tion. Use only the latest edition of this manual. Authorized Yamaha dealers are notified
periodically of modifications and significant changes in specifications and procedures, and
these are incorporated in successive editions of this manual.
50G, 60F, 70B, 75C, 90A
1999 Yamaha Motor Co., Ltd.
1st Edition, February 1999
No part of this publication may be
reproduced or transmitted in any form or by
any means including photocopying and
recording without the written permission of
the copyright holder. Such written
permission must also be obtained before
any part of this publication is stored in a
retrieval system of any nature.
HOW TO USE THIS MANUAL
This manual provides the mechanic with descriptions of the operations of disassembly,
repair, assembly, adjustment and inspection, each of which is presented in a sequential, step-
To assist you to find your way about this manual, the Section Title and Major Heading is
given at the head of every page.
An Index to contents is provided on the first page of each section.
Multiple models are shown in this manual. These indications are noted as follows.
Some illustrations in this manual may differ from the model you have. T