Yamaha 40V User manual

LIT-18616-01-81 290320
SERVICE
MANUAL
40V, 50H
WORLD WIDE
40W, 50W
USA/CANADA

E
A20000-0
NOTICE
This manual has been prepared by the Yamaha Motor Company 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 under-
standing 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.
A10001-0*
40V/50H
SERVICE MANUAL
 1997 Yamaha Motor Corporation, USA
1st Edition, August 1997
All rights reserved.
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.
Printed in U.S.A.
LIT-18616-01-81

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HOW TO USE THIS MANUAL
MANUAL FORMAT
All of the procedures in this manual are organized in a sequential, step-by-step format. The
information has been complied to provide the mechanic with an easy to read, handy refer-
ence that contains comprehensive explanations of all disassembly, repair, assembly, and
inspection operations.
In this revised format, the condition of a faulty component will precede an arrow symbol and
the course of action required will follow the symbol, e.g.,
●
Bearings
Pitting/Damage → Replace.
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.
MODEL INDICATION
Multiple models are shown in this manual. These indications are noted as follows.
THE ILLUSTRATIONS
Some illustrations in this manual may differ from the model you have. This is because a pro-
cedure described may relate to several models, though only one may be illustrated. (The
name of model described will be mentioned in the description).
REFERENCES
These have been kept to a minimum; however, when you are referred to another section of
the manual, you are told the page number to go to.
Model name 40VMH 40VMHD 40VMHO 40VMO 40VWH 40VE 40VEO 40VEHTO 40VET
USA and
CANADA name C40MH 40MH C40ER 40ER P40TH C40TR
Indication 40VMH 40VMHD 40VMHO 40VMO 40VWH 40VE 40VEO 40VEHTO 40VET
Model name 40VETO 50HMHO 50HMHD 50HMO 50HMDO 50HWHD 50HEDO 50HET 50HETO
USA and
CANADA name 40TR 50ER C50TR 50TR
Indication 40VETO 50HMHO 50HMHD 50HMO 50HMDO 50HWHD 50HEDO 50HET 50HETO

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WARNINGS, CAUTIONS AND NOTES
Attention is drawn to the various Warnings, Cautions and Notes which distinguish important
information in this manual in the following ways.
The Safety Alert Symbol means ATTENTION! BECOME ALERT! YOUR SAFETY IS
INVOLVED!
WARNING
Failure to follow WARNING instructions could result in severe injury or death to the machine
operator, a bystander, or a person inspecting or repairing the outboard motor.
CAUTION:
A CAUTION indicates special precautions that must be taken to avoid damage to the out-
board motor.
NOTE:
A NOTE provides key information to make procedures easier or clearer.
SPECIFICATIONS
These are given in bold type at each procedure. It is not necessary to leave the section deal-
ing with the procedure in order to look up the specifications.
It is important to note the differences in specifications of models. When a procedure relates to
more than one model, the main differences in specifications will be shown in a following table.
Model name 40VMH 40VMHD 40VMHO 40VMO 40VWH 40VE 40VEO 40VEHTO 40VET
Starting system Manual Manual Manual Manual Manual
& Electric Electric Electric Electric Electric
Control system Tiller Tiller Tiller Remote Tiller Remote Remote Tiller Remote
Trim/Tilt system Manual tilt Hydro tilt Manual tilt Manual tilt Hydro tilt Manual tilt Manual tilt PTT PTT
Lubrication system Pre-Mixed Pre-Mixed Oil injection Oil injection Pre-Mixed Pre-Mixed Oil injection Oil injection Pre-Mixed
Warning indicator
lamp 1111113——
Enrichment system Choke Choke Choke Choke Prime Start Prime Start Prime Start Prime Start Prime Start
Model name 40VETO 50HMHO 50HMHD 50HMO 50HMDO 50HWHD 50HEDO 50HET 50HETO
Starting system Electric Manual Manual Manual Manual Manual &
Electric Electric Electric Electric
Control system Remote Tiller Tiller Remote Remote Tiller Remote Remote Remote
Trim/Tilt system PTT Manual tilt Hydro tilt Manual tilt Hydro tilt Hydro tilt Hydro tilt PTT PTT
Lubrication system Oil injection Oil injection Pre-Mixed Oil injection Oil injection Pre-Mixed Oil injection Oil injection Oil injection
Warning indicator
lamp 3111113——
Enrichment system Prime Start Choke Choke Choke Choke Prime Start Prime Start Prime Start Prime Start

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HOW TO READ DESCRIPTIONS
1. A disassembly installation job mainly consists of the exploded diagram 1 .
2. The numerical figures represented by the number 2 indicates the order of the job steps.
3. The symbols represented by the number 3 indicates the contents and notes of the job.
For the meanings of the symbols, refer to the next page(s).
4. The REMOVAL AND INSTALLATION CHART 4 is attached to the exploded diagram and
explains the job steps, part names, notes for the jobs, etc.
5. The SERVICE POINTS, other than the exploded diagram, explains in detail the items diffi-
cult to explain in the exploded diagram or REMOVAL AND INSTALLATION CHART, the
Service points requiring the detailed description 5 , etc.

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A50001-1-4
SYMBOLS
Symbols 1 to 9 are designed as thumb-
tabs to indicate the content of a chapter.
1 General Information
2 Specifications
3 Periodic Inspection and Adjustment
4 Fuel System
5 Power Unit
6 Lower Unit
7 Bracket Unit
8 Electrical System
9 Trouble-analysis
Symbols 0 to F indicate specific data:
0 Special tool
A Specified liquid
B Specified grease
C Specified engine speed
D Specified torque
E Specified measurement
F Specified electrical value
[Resistance ( Ω ), Voltage (V), Electric current
(A)]
Symbol G to J in an exploded diagram
indicate grade of lubricant and location of
lubrication point:
G Apply Yamaha 2-stroke outboard motor oil
H Apply Yamaha gear-case lubricant
I Apply molybdenum disulfide oil
J Apply water resistant grease (Yamaha
grease A, Yamaha marine grease)
Symbols K to N in an exploded diagram
indicate grade of sealing or locking agent,
and location of application point:
K Apply Gasket maker

L Apply LOCTITE

No. 271 (Red LOCTITE)
MApply LOCTITENo. 242 (Blue LOCTITE)
NApply LOCTITENo. 572
NOTE:
In this manual, the above symbols may not
be used in every case.
12
34
56
78
90
AB
CD
EF
GH
IJ
KL
MN
GEN
INFO SPEC
INSP
ADJ FUEL
POWR
LOWR
BRKT –+
ELEC
TRBL
ANLS
T
R
.
.
EG
MA
GM
271
LT
242
LT
572
LT

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INDEX
GENERAL INFORMATION
1
SPECIFICATIONS
2
SPEC
PERIODIC INSPECTION AND
ADJUSTMENT
3
FUEL SYSTEM
4
FUEL
POWER UNIT
5
POWR
LOWER UNIT
6
LOWER
BRACKET UNIT
7
BRKT
ELECTRICAL SYSTEM
8
ELEC
TROUBLE-ANALYSIS
9
GEN
INFO
INSP
ADJ
–+
TRBL
ANLS
A30000-0

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1
2
3
4
5
6
7
8
9
GEN
INFO
CHAPTER 1
GENERAL INFORMATION
IDENTIFICATION ............................................................................................. 1-1
SERIAL NUMBER ..................................................................................... 1-1
STARTING SERIAL NUMBERS ............................................................... 1-1
SAFETY WHILE WORKING ............................................................................ 1-2
FIRE PREVENTION ................................................................................... 1-2
VENTILATION........................................................................................... 1-2
SELF-PROTECTION.................................................................................. 1-2
OILS, GREASES AND SEALING FLUIDS................................................ 1-2
GOOD WORKING PRACTICES ................................................................ 1-3
DISASSEMBLY AND ASSEMBLY ........................................................... 1-4
SPECIAL TOOLS ............................................................................................. 1-5
MEASURING ............................................................................................ 1-6
REMOVAL AND INSTALLATION ............................................................ 1-8

1-1
GEN
INFO
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IDENTIFICATION
A60000-1*
IDENTIFICATION
SERIAL NUMBER
The serial number of the outboard motor is
stamped on a plate attached to the port side
of the clamp bracket.
NOTE:
As an antitheft measure, a special label on
which the outboard motor serial number is
stamped is bonded to the portside of the
clamp bracket. The label is specially treated
so that peeling it off causes cracks across
the serial number.
1 Model name
2 Approved model No.
3 Transom height
4 Serial number
STARTING SERIAL NUMBERS
The starting serial number blocks are as fol-
lows:
Model Approved
model
code
Starting
serial No.
Model Approved
model
code
Starting
serial No.
World-
wide
USA,
CANADA
World-
wide
USA,
CANADA
40VMH C40MH
6H4
S: 010262 ~ 50HMHO —
6H5
S: 190662 ~
L: 310801 ~ 50HMHD — L: 310380 ~
40VMHD — L: 560290 ~ 50HMO — S: 260189 ~
40VMHO 40MH S: 191877 ~ 50HMDO — L: 560258 ~
L: 491566 ~ 50HWHD — L: 850194 ~
40VMO — S: 290284 ~ 50HEDO 50ER S: 090431 ~
L: 860312 ~ L: 521079 ~
40VWH — L: 510116 ~ 50HET C50TR L: 900101 ~
40VE C40ER S: 060285 ~
50HETO 50TR
S: 210142 ~
L: 360173 ~ L: 444058 ~
40VEO 40ER
S: 110760 ~ X: 750216 ~
L: 842362 ~
X: 740146 ~
40VEHTO P40TH L: 430386 ~
40VET C40TR L: 921505 ~
40VETO 40TR
S: 880367 ~
L: 544974 ~
X: 900196 ~

1-2
GEN
INFO
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SAFETY WHILE WORKING
SAFETY WHILE WORKING
The procedures given in this manual are
those recommended by Yamaha to be fol-
lowed by Yamaha dealers and their
mechanics.
FIRE PREVENTION
Gasoline (petrol) is highly flammable.
Petroleum vapor is explosive if ignited.
Do not smoke while handling, and keep it
away from heat, sparks, and open flames.
VENTILATION
Petroleum vapor is heavier than air and is
deadly if inhaled in large quantities. Engine
exhaust gases are harmful to breathe.
When test-running an engine indoors,
maintain good ventilation.
SELF-PROTECTION
Protect your eyes with suitable safety
glasses or safety goggles when using com-
pressed air, when grinding or when doing
any operation which may cause particles to
fly off. Protect hands and feet by wearing
safety gloves or protective shoes if appro-
priate to the work you are doing.
OILS, GREASES AND SEALING
FLUIDS
Use only genuine Yamaha oils, greases and
sealing fluids or those recommended by
Yamaha.

1-3
GEN
INFO
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SAFETY WHILE WORKING
Under normal conditions of use, there
should be no hazards from the use of the
lubricants mentioned in this manual, but
safety is all-important, and by adopting
good safety practices, any risk is mini-
mized.
A summary of the most important precau-
tions is as follows:
1. While working, maintain good stan-
dards of personal and industrial
hygiene.
2. Clothing which has become contami-
nated with lubricants should be
changed as soon as practicable, and
laundered before further use.
3. Avoid skin contact with lubricants; do
not, for example, place a soiled wiping-
rag in one’s pocket.
4. Hands and any other part of the body
which have been in contact with lubri-
cants or lubricant-contaminated cloth-
ing, should be thoroughly washed with
hot water and soap as soon as practica-
ble.
5. To protect the skin, the application of a
suitable barrier cream to the hands
before working is recommended.
6. A supply of clean lint-free cloths should
be available for wiping purposes.
GOOD WORKING PRACTICES
1. The right tools
Use the special tools that are advised to
protect parts from damage. Use the
right tool in the right manner — don’t
improvise.
2. Tightening torque
Follow the torque tightening instruc-
tions. When tightening bolts, nuts and
screws, tighten the large sizes first, and
tighten inner-positioned fixings before
outer-positioned ones.

1-4
GEN
INFO
E
SAFETY WHILE WORKING
3. Non-reusable items
Always use new gaskets, packings, O-
rings, split-pins and circlips etc. on
reassembly.
DISASSEMBLY AND ASSEMBLY
1. Clean parts with compressed-air on dis-
assembling them.
2. Oil the contact surfaces of moving parts
on assembly.
3. After assembly, check that moving
parts operate normally.
4. Install bearings with the manufacturer’s
markings on the side exposed to view,
and liberally oil the bearings.
5. When installing oil seals, apply a light
coating of water-resistant grease to the
outside diameter.

1-5
GEN
INFO
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SPECIAL TOOLS
A80000-0*
SPECIAL TOOLS
The use of correct special tools recommended by Yamaha will aid the work and enable accu-
rate assembly and tune-up. Improvisations and use of improper tools can cause damage to
the equipment.
NOTE:
●
For U.S.A. and Canada, use part number starting with “YB-”, “YU-” or “YW-”.
●
For others, use part number starting with “90890-”.

1-6
GEN
INFO
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SPECIAL TOOLS
MEASURING
Tool name
Tool No.
Use for:
USA and
Canada a
Except for
USA and
Canada b
1 Tachometer YU-08036-A 90890-06760 Idle speed
2 Dynamic spark tester YM-34487 90890-06754 Ignition system
3 C.D.I. tester YU-91022-B N.A. Ignition system
4 Mity Vac YB-35956 90890-06756 Fuel joint
5 Pressure tester YB-35956 90890-06762 Lower case
6 Dial indicator YU-03097 90890-01252 Backlash
7 Backlash indicator YB-06265 90890-06706 Backlash
8 Magnetic flexible stand YU-34481 90890-06705 Backlash
9 Backlash adjusting plate YB-07003 N.A. Backlash
10 Thickness gauge YU-26900-9 N.A. Shimming
11 Pinion height gauge N.A. 90890-06702 Pinion shimming
12 Digital caliper N.A. 90890-06704 Pinion
shimming
Forward
shimming
13 Gauge block YB-34432-9 N.A. Pinion shimming
14 Adapter plate YB-34432-10 N.A. Pinion shimming
15 Gauge base YB-34432-11 N.A. Pinion shimming
16 Clamp YB-34432-17 N.A. Pinion shimming
17 Shimming plate N.A. 90890-06701 Forward shimming
18 Base plate YB-34446-1 N.A. Forward shimming
19 Compression spring YB-34446-3 N.A. Forward shimming
20 Press plate YB-34446-4 N.A. Forward shimming
21 Gauge pin YB-34446-7 N.A. Forward shimming
22 Digital multimeter YU-34899-A 90890-06752 Electrical
23 Pocket tester YU-03112 90890-03112 Electrical
24 Spins test harness YB-06757 90890-06757 Peak voltage measurement

1-7
GEN
INFO
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SPECIAL TOOLS

1-8
GEN
INFO
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SPECIAL TOOLS
REMOVAL AND INSTALLATION
Tool name
Tool No.
Use for:
USA and
Canada a
Except for
USA and
Canada b
1Small end bearing
needle installer YB-06106 90890-06526 Small end
2 Bearing separator YB-06219 90890-06534 Crank shaft
bearing
Reverse gear
bearing
Forward
gear inner
bearing
3 Flywheel holder YB-06139 90890-06522 Flywheel
4 Flywheel puller YB-06117 90890-06521 Flywheel
5 Stopper guide plate N.A. 90890-06501 Propeller
shaft housing
Reverse gear
bearing
Drive shaft
outer bearing
6 Bearing housing puller YB-06234 90890-06503 Propeller shaft housing
7 Center bolt N.A. 90890-06504 Propeller shaft housing
8 Universal puller YB-06117 N.A. Propeller shaft housing
9 Oil seal installer YB-06168 N.A. Propeller shaft oil seal
10 Needle bearing remover YB-06112 90890-06614 Propeller shaft
needle bearing
11 Needle bearing installer YB-06111 90890-06614 Propeller shaft
needle bearing
12 Bearing outer race puller
clow N.A. 90890-06535 Reverse gear bearing
13 Stopper guide stand N.A. 90890-06538 Reverse gear
bearing
Forward
gear outer
bearing
14 Slide hammer set YB-06096 N.A. Reverse gear
bearing
Drive shaft
outer bearing
Forward
gear outer
bearing
15 Pinion nut wrench N.A. 90890-06505 Pinion nut
16 Socket adapter N.A. 90890-06506 Pinion nut
17 Drive shaft holder YB-06079 90890-06517 Pinion nut
18 Needle bearing attach-
ment YB-06063 90890-06614 Drive shaft needle bearing
19 Drive shaft needle bear-
ing depth stop YB-34473 N.A. Drive shaft needle bearing
20 Bearing installer YB-06167 90890-06628 Drive shaft oil seal
21 Bearing installer YB-06110 90890-06627 Drive shaft outer bearing
22 Bearing installer YB-06270-A 90890-06640 Forward gear inner bearing

1-9
GEN
INFO
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SPECIAL TOOLS

1-10
GEN
INFO
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SPECIAL TOOLS
Tool name
Tool No.
Use for:
USA and
Canada a
Except for
USA and
Canada b
23 Bearing outer race puller N.A. 90890-06523 Forward gear outer bearing
24 Bearing outer race puller
clow N.A. 90890-06532 Forward gear outer bearing
25 Bearing installer YB-41446 90890-06626 Forward gear outer bearing
26 Shift rod wrench YB-06052 N.A. Shift rod
27 Tilt cylinder wrench YB-06175-2B 90890-06544 PTT
28 Bearing depth plate N.A. 90890-06603
Propeller
shaft needle
bearing
Drive shaft
needle bear-
ing
29 Driver rod - SL N.A. 90890-06602 Drive shaft needle bearing
30 Driver rod - SS N.A. 90890-06604 Propeller shaft
needle bearing
31 Driver rod - L YB-06071 90890-06605 Bearing and oil seal
32 Driver rod - S N.A. 90890-06606 Bearing and oil seal
33 Driver rod - M10 N.A. 90890-06652 Bearing and oil seal