Page 1
40X
E40X
290545
SERVICE MANUAL
66T-28197-5F-11
Page 2
NOTICE
This manual has been prepared by Yamaha 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 Yamaha has a policy of continuously improving its products, models may differ in detail
from the descriptions and illustrations given in this publication. 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.
Important information
Particularly important information is distinguished in this manual by the following notations:
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 outboard motor.
NOTE:
A NOTE provides key information to make procedures easier or clearer.
1
40X, E40X
SERVICE MANUAL
©2003 by Yamaha Motor Co., Ltd.
1st Edition, December 2003
All rights reserved.
Any reprinting or unauthorized use
without the written permission of
Yamaha Motor Co., Ltd.
is expressly prohibited.
Printed in Japan
Page 3
Contents
General information
Specifications
Periodic checks and adjustments
Fuel system
Power unit
GEN
INFO
SPEC
CHK
ADJ
FUEL
POWR
1
2
3
4
5
Lower unit
Bracket unit
Electrical systems
Troubleshooting
Index
LOWR
BRKT
–+
ELEC
TRBL
SHTG
6
7
8
9
Page 4
Page 5
GEN
INFO
General information
How to use this manual.................................................................................1-1
Manual format............................................................................................1-1
Symbols.....................................................................................................1-2
Safety while working......................................................................................1-3
Fire prevention...........................................................................................1-3
Ventilation..................................................................................................1-3
Self-protection ...........................................................................................1-3
Parts, lubricants, and sealants ..................................................................1-3
Good working practices .............................................................................1-4
Disassembly and assembly .......................................................................1-4
1
2
Identification...................................................................................................1-5
Applicable models .....................................................................................1-5
Serial number ............................................................................................1-5
Propeller selection.........................................................................................1-5
Propeller size.............................................................................................1-5
Selection....................................................................................................1-6
Predelivery checks ........................................................................................1-6
Checking the fuel system ..........................................................................1-6
Checking the gear oil level ........................................................................1-6
Checking the battery (WH, W)...................................................................1-6
Checking the outboard motor mounting height..........................................1-7
Checking the remote control cables (remote control model) .....................1-7
Checking the steering system ...................................................................1-8
Checking the gear shift and throttle operation...........................................1-8
Checking the engine start switch and engine stop lanyard switch ............1-9
Checking the cooling water pilot hole ........................................................1-9
Test run .....................................................................................................1-9
Break-in ...................................................................................................1-10
After test run ............................................................................................1-10
3
4
5
6
7
66T5F11
8
9
Page 6
GEN
INFO
General information
How to use this manual
Manual format
The format of this manual has been designed to make service procedures clear and easy to understand. Use the information below as a guide for effective and quality service.
1
Parts are shown and detailed in an exploded diagram and are listed in the components list.
2
Tightening torque specifications are provided in the exploded diagrams and after a numbered
step with tightening instructions.
3
Symbols are used to indicate important aspects of a procedure, such as the grade of lubricant
and lubrication point.
4
The components list consists of part names and part quantities, as well as bolt and screw dimensions.
5
Service points regarding removal, checking, and installation are shown in individual illustrations
to explain the relevant procedure.
NOTE:
For troubleshooting procedures, see Chapter 9, “Troubleshooting.”
1
LOWR
Lower unit
No. Part name Q’ty Remarks
1 Lower unit 1
2 Plastic tie 1
3Hose 1
4 Check screw 1
5 Gasket 2
6 Dowel pin 2
7 Bolt 4 M10 40 mm
8 Drain screw 1
9Grommet 1
10 Bolt 1 M10 45 mm
11 Bolt 1 M8 60 mm
12 Thrust washer 1
13 Propeller 1
14 Washer 1
15 Washer 1
16 Cotter pin 1
17 Propeller nut 1
18 Trim tab 1
6-5
Lower unit
Not reusable
Not reusable
Not reusable
3
4
2
62Y5A11
1
LOWR
Removing the drive shaft
1. Remove the drive shaft assembly and
pinion, and then pull out the forward
gear.
Disassembling the drive shaft
1. Install the pinion nut 1, tighten it finger
tight, and then remove the drive shaft
bearing 2 using a press.
CAUTION:
• Do not press the drive shaft threads
directly.
• Do not reuse the bearing, always
replace it with a new one.
Disassembling the forward gear
1. Remove the taper roller bearing from the
forward gear using a press.
Lower unit
S62Y6850K
Drive shaft holder 4 1: 90890-06518
Pinion nut holder 2: 90890-06505
Socket adapter 2 3: 90890-06507
Bearing inner race attachment 3:
90890-06639
CAUTION:
Do not reuse the bearing, always replace
it with a new one.
Bearing separator 1: 90890-06534
2. Remove the needle bearing from the forward gear.
CAUTION:
Do not reuse the bearing, always replace
it with a new one.
a
Stopper guide plate 2: 90890-06501
Stopper guide stand 3:
90890-06538
Bearing puller 4: 90890-06535
Bearing puller claw 1 5:
90890-06536
S62Y6740K
1-1
5
6-19
62Y5A11
66T5F11
Page 7
Symbols
T
R
.
.
D
242
LT
The symbols below are designed to indicate the content of a chapter.
How to use this manual
General information
GEN
INFO
Specifications
SPEC
Periodic checks and adjustments
CHK
ADJ
Symbols 1 to 6 indicate specific data.
123456
Fuel system
FUEL
Power unit
POWR
Lower unit
LOWR
Bracket unit
BRKT
Electrical systems
ELEC
Troubleshooting
– +
TRBL
SHTG
1
2
3
4
Special tool
1
Specified oil or fluid
2
Specified engine speed
3
Specified tightening torque
4
Symbols 7 to C in an exploded diagram indicate the grade of lubricant and the lubrication point.
7890ABC
A M
E G
Apply 2-stroke outboard motor oil
7
Apply gear oil
8
Apply water resistant grease (Yamaha grease A)
9
Apply molybdenum disulfide grease
0
Symbols D to I in an exploded diagram indicate the type of sealant or locking agent and the application point.
DEFGHI
GM
4
LT
271
Specified measurement
5
Specified electrical value
6
(resistance, voltage, electric current)
C I
Apply corrosion resistant grease
A
(Yamaha grease D)
Apply low temperature resistant grease
B
(Yamaha grease C)
Apply injector grease
C
LT
572
SS
5
6
7
8
9
Apply Gasket Maker
D
Apply Yamabond No. 4
E
Apply LOCTITE 271 (red)
F
66T5F11
Apply LOCTITE 242 (blue)
G
Apply LOCTITE 572
H
Apply silicon sealant
I
1-2
Page 8
GEN
INFO
General information
Safety while working
To prevent an accident or injury and to
ensure quality service, follow the safety procedures provided below.
Fire prevention
Gasoline is highly flammable.
Keep gasoline and all flammable products
away from heat, sparks, and open flames.
Ventilation
Gasoline vapor and exhaust gas are heavier
than air and extremely poisonous. If inhaled
in large quantities they may cause loss of
consciousness and death within a short time.
When test running an engine indoors (e.g., in
a water tank) be sure to do so where adequate ventilation can be maintained.
1
Parts, lubricants, and sealants
Use only genuine Yamaha parts, lubricants,
and sealants or those recommended by
Yamaha, when servicing or repairing the outboard motor.
Under normal conditions, the lubricants mentioned in this manual should not harm or be
hazardous to your skin. However, you should
follow these precautions to minimize any risk
when working with lubricants.
Self-protection
Protect your eyes by wearing safety glasses
or safety goggles during all operations involving drilling and grinding, or when using an air
compressor.
Protect your hands and feet by wearing protective gloves and safety shoes when necessary.
1-3
1. Maintain good standards of personal and
industrial hygiene.
2. Change and wash clothing as soon as
possible if soiled with lubricants.
3. Avoid contact with skin. Do not, for
example, place a soiled rag in your
pocket.
4. Wash hands and any other part of the
body thoroughly with soap and hot water
after contact with a lubricant or lubricant
soiled clothing has been made.
5. To protect your skin, apply a protective
cream to your hands before working on
the outboard motor.
66T5F11
Page 9
Safety while working
6. Keep a supply of clean, lint-free cloths for
wiping up spills, etc.
Good working practices
Special service tools
Use the recommended special service tools
to protect parts from damage. Use the right
tool in the right manner—do not improvise.
Tightening torques
Follow the tightening torque specifications
provided throughout the manual. When tightening nuts, bolts, and screws, tighten the
large sizes first, and tighten fasteners starting
in the center and moving outward.
Non-reusable parts
Always use new gaskets, seals, O-rings, cotter pins, circlips, etc., when installing or
assembling parts.
Disassembly and assembly
1. Use compressed air to remove dust and
dirt during disassembly.
2. Apply engine oil to the contact surfaces
of moving parts before assembly.
3. Install bearings with the manufacture
identification mark in the direction indicated in the installation procedure. In
addition, be sure to lubricate the bearings
liberally.
4. Apply a thin coat of water-resistant
grease to the lip and periphery of an oil
seal before installation.
5. Check that moving parts operate normally after assembly.
1
2
3
4
5
6
7
8
9
66T5F11
1-4
Page 10
GEN
INFO
General information
Identification
Applicable models
This manual covers the following models.
Applicable models
40XWH, 40XW, E40XMH, E40XW
Serial number
The outboard motor serial number is
stamped on a label attached to the port
clamp bracket.
1
Propeller selection
1
The performance of a boat and outboard
motor will be critically affected by the size
and type of propeller you choose. Propellers
greatly affect boat speed, acceleration,
engine life, fuel economy, and even boating
and steering capabilities. An incorrect choice
could adversely affect performance and
could also seriously damage the engine.
Use the following information as a guide for
selecting a propeller that meets the operating
conditions of the boat and the outboard
motor.
Propeller size
The size of the propeller is indicated on a
propeller blade, on the propeller boss end, on
the side of the propeller boss.
Model name
1
Approved model code
2
Transom height
3
Serial number
4
Model name
40XWH
40XW
E40XMH
E40XW
Approved
model code
Starting
serial No.
66TK 1008141–
× -
a
bc
× -
× -
a
bc
S69W1030
S69W1040
1-5
a
bc
S69W1050
66T5F11
Page 11
Identification / Propeller selection / Predelivery checks
Propeller diameter (in inches)
a
Propeller pitch (in inches)
b
Propeller type (propeller mark)
c
Selection
When the engine speed is at the full throttle
operating range (4,500–5,500 r/min), the
ideal propeller for the boat is one that provides maximum performance in relation to
boat speed and fuel consumption.
1
Propeller size (in) Material
10 1/4 × 14 - G
10 1/4 × 15 - G
10 1/4 × 16 - G
10 3/4 × 16 - G
10 3/4 × 17 - G
11 × 15 - G
11 1/8 × 13 - G
11 1/4 × 14 - G
Aluminum
11 3/8 × 12 - G
11 1/2 × 13 - G
11 5/8 × 11 - G
11 3/4 × 10 - G
11 3/4 × 12 - G
12 × 11 - G
12 1/4 × 8 - G
12 1/4 × 9 - G
CAUTION:
Use pre-mixed fuel only.
Fuel and oil mixing ratio is 50:1. For
break-in period, 25:1 mixture shall be
used.
Checking the gear oil level
1. Check the gear oil level.
2
3
4
5
6
Predelivery checks
To make the delivery process smooth and
efficient, the predelivery checks should be
completed as explained below.
Checking the fuel system
1. Check that the fuel hoses are securely
connected and that the fuel tank is full
with fuel.
66T5F11
1
7
S60V1290
Checking the battery (WH, W)
1. Check the capacity, electrolyte level, and
specified gravity of the battery.
Recommended battery capacity:
CCA/EN: 430 A
20HR/IEC: 70 Ah
Electrolyte specified gravity:
1.280 at 20 °C (68 °F)
1-6
8
9
Page 12
GEN
INFO
2. Check that the positive and negative battery leads are securely connected.
Checking the outboard motor
mounting height
1. Check that the anti-cavitation plate is
between the bottom of the boat and a
maximum of 25 mm (1 in) a below it. If
the mounting height is too high, cavitation will occur and propulsion will be
reduced. Also, the engine speed will
increase abnormally and cause the
engine to overheat. If the mounting
height is too low, water resistance will
increase and reduce engine efficiency.
General information
a
S6D51030
NOTE:
The optimum mounting height is affected by
the combination of the boat and the outboard
motor. To determine the optimum mounting
height, test run the outboard motor at different heights.
2. Check that the clamp brackets are
secured with the clamp screws.
Checking the remote control cables
(remote control model)
1. Set the remote control lever to the neutral position and fully close the throttle
lever.
2. Check that the throttle cam 1 is in its
fully closed position and align the center
of the throttle cam roller 2 with the mark
a
on the throttle cam.
3. Check that the shift link lever 3 is in the
neutral position.
N
R
b
3
F
S66T1030
S66T1050
WARNING
The shift/throttle cable joint must be
screwed in a minimum of 8.0 mm (0.31 in)
b
.
1-7
66T5F11
Page 13
Predelivery checks
Checking the steering system
1. Check the steering friction for proper
adjustment.
NOTE:
• To increase the friction, turn the friction
adjusting bolt in direction a.
• To decrease the friction, turn the friction
adjusting bolt in direction b.
2. Check that the steering operates
smoothly.
Checking the gear shift and throttle
operation
1. Check that the gear shift operates
smoothly when the remote control lever
or shift lever is shifted from neutral to forward or reverse.
2. Check that the throttle operates smoothly
when the throttle grip (tiller handle
model) is turned from the fully closed
position to the fully open position a.
Check that the throttle operates smoothly
when the remote control lever (remote
control model) is shifted from forward or
reverse to the fully open positions a.
R
N
F
0 100%
1
2
3
4
S66T1060
S66T1040
3. Check that there is no interference with
wires or hoses when the outboard motor
is steered.
a
S66T1070
a
5
N
F
R
a
S69J1210
6
7
8
9
66T5F11
1-8
Page 14
GEN
INFO
Checking the engine start switch and
engine stop lanyard switch
1. Check that the engine starts when the
engine start switch is turned to START.
2. Check that the engine turns off when the
engine start switch is turned to OFF.
3. Check that the engine turns off when the
engine stop lanyard switch is pushed or
the engine stop lanyard is pulled from the
engine stop lanyard switch.
General information
S60V1070
Checking the cooling water pilot
hole
1. Check that cooling water is discharged
from the cooling water pilot hole.
S66T1080
S66T1090
S66T3050
Test run
1. Start the engine, and then check that the
gear shift operates smoothly.
2. Check the engine idle speed after the
engine has been warmed up.
3. Operate at trolling speed.
4. Run the outboard motor for 1 hour at
3,000 r/min or at half throttle, then for
another hour at 4,000 r/min or at 3/4
throttle.
5. Check that the outboard motor does not
tilt up when shifting into reverse and that
water does not flow in over the transom.
NOTE:
The test run is part of the break-in operation.
1-9
66T5F11
Page 15
Break-in
During the test run, perform the break-in
operation in the following four stages.
1. First 10 minutes a of operation at idle
Predelivery checks
2. Fifty minutes b at 3,000 r/min or less
3. One hour c at 4,000 r/min or less
4. Eight hours d at 5,000 r/min or less with
repeated wide-open-throttle operation for
5 minutes or less
cdaÈb
0
È
Hour
After test run
1. Check for water in the gear oil.
1
210
S60V1120
1
2
3
4
5
2. Check for fuel leakage in the cowling.
3. Flush the cooling water passage with
fresh water using the flushing kit and with
the engine running at idle.
6
7
8
9
66T5F11
1-10
Page 16
GEN
INFO
General information
— MEMO —
1-11
66T5F11
Page 17
SPEC
Specifications
General specifications...................................................................................2-1
Maintenance specification ............................................................................2-3
Power unit..................................................................................................2-3
Lower unit ..................................................................................................2-5
Electrical ....................................................................................................2-5
Dimensions................................................................................................2-7
Tightening torques.........................................................................................2-9
Specified torques.......................................................................................2-9
General torques.......................................................................................2-10
1
2
3
4
5
6
7
8
9
66T5F11
Page 18
SPEC
Specifications
General specifications
Item Unit
40XWH 40XW E40XMH E40XW
Dimension
Overall length mm (in)
1,073 (42.2)
675 (26.6)
Overall width mm (in) 402 (15.8) 362 (14.3) 402 (15.8) 362 (14.3)
Overall height
(S) mm (in) — 1,237 (48.7) —
(L) mm (in)
1,364 (53.7)
(X) mm (in) —
Boat transom height
(S) mm (in) — 381 (15.0) —
(L) mm (in) 508 (20.0) — 508 (20.0)
(X) mm (in) — 635 (25.0) —
Weight
(with aluminum propeller)
(S) kg (lb) —
(L) kg (lb)
78.0 (172.0)
74.6 (164.5) 72.0 (158.8)
(X) kg (lb) —
Performance
Maximum output kW (hp) 29.4 (40) at 5,000 r/min
Full throttle operating range r/min 4,500–5,500
Maximum fuel consumption L (US gal,
20 (5.3, 4.4) at 5,500 r/min
Imp gal)/hr
Engine idle speed r/min 950–1,050
Power unit
Type 2-stroke
Cylinder quantity L2
Total displacement cm
3
(cu. in) 703 (42.9)
Bore × stroke mm (in) 80.0 × 70.0 (3.15 × 2.76)
Compression ratio 6.0
Intake system Reed valve
Scavenging system Loop charge
Control system Tiller
handle
Remote
control
Starting system Manual and electric Manual Manual and
Fuel system Carburetor
Ignition control system CDI
Maximum generator output V, A 12, 6.0 — 12, 6.0
Starting enrichment Choke valve
Spark plug B7HS (NGK), BR7HS (NGK)
Cooling system Water
Exhaust system Propeller boss
Lubrication system Pre-mixed fuel
Model
1,073 (42.2)
675 (26.6)
— 1,364 (53.7)
1,476 (58.1)
—
73.6 (162.3) 76.2 (168.0)
76.7 (169.1)
Tiller
handle
Remote
control
electric
2
—
—
—
2-1
66T5F11
Page 19
General specifications
Item Unit
Fuel and oil
Fuel type Regular gasoline
Engine oil 2-stroke outboard motor oil
Engine oil grade
Fuel and oil mixing ratio 50:1
Gear oil type Hypoid gear oil
Gear oil grade
Gear oil quantity cm
Bracket unit
Tilt angle Degree 8, 12, 16, 20, 24
(at 12° boat transom)
Tilt-up angle Degree 68
Steering angle Degree 45 + 45
Drive unit
Gear shift positions F-N-R
Gear ratio 2.00 (26/13)
Reduction gear type Spiral bevel gear
Clutch type Dog clutch
Propeller shaft type Spline
Propeller direction (rear view) Clockwise
Propeller mark G
Electrical
Battery minimum capacity
CCA/EN A 430 — 430
20HR/IEC Ah 70 — 70
(*1)
Meeting both API and SAE requirements
(*2)
CCA: Cold Cranking Ampere
EN: European Norm (European standard)
IEC: International Electrotechnical Commission
(*1)
API
(*2)
NMMA-certified
SAE
3
Imp oz)
(US oz,
40XWH 40XW E40XMH E40XW
430 (14.54, 15.17)
Model
TC-W3
GL-4
90
1
2
3
4
5
6
7
66T5F11
8
9
2-2
Page 20
SPEC
Specifications
Maintenance specification
Power unit
Item Unit
40XWH 40XW E40XMH E40XW
Power unit
Minimum compression
pressure
(*1)
kPa
(kgf/cm2, psi)
Cylinder heads
Warpage limit
mm (in) 0.1 (0.0039)
(lines indicate straightedge
position)
Cylinders
Bore size mm (in) 80.000–80.020 (3.1496–3.1504)
Bore size limit mm (in) 80.100 (3.1535)
Taper limit mm (in) 0.08 (0.0032)
Out-of-round limit mm (in) 0.05 (0.0020)
Pistons
Piston diameter (D) mm (in) 79.910–79.934 (3.1461–3.1470)
Measuring point (H) mm (in) 10 (0.39)
Piston-to-cylinder clearance mm (in) 0.085–0.090 (0.0033–0.0035)
(Limit) mm (in) 0.14 (0.0055)
Piston pin boss bore mm (in) 19.904–19.915 (0.7836–0.7841)
Oversize piston
1st mm (in) 0.25 (0.010)
2nd mm (in) 0.50 (0.020)
Oversize piston diameter
1st mm (in) 80.160–80.184 (3.1559–3.1568)
2nd mm (in) 80.410–80.434 (3.1657–3.1667)
Piston pins
Outside diameter mm (in) 19.895–19.900 (0.7833–0.7835)
(*1)
Measure conditions:
Ambient temperature 20 °C (68 °F), wide open throttle, with spark plugs removed from all cylinders.
The figures are for reference only.
Model
630 (6.3, 91)
2
2-3
66T5F11
Page 21
Maintenance specification
Item Unit
Piston rings
Top ring
Dimension B mm (in) 1.97–1.99 (0.0776–0.0783)
Dimension T mm (in) 2.40–2.60 (0.0945–0.1024)
End gap mm (in) 0.30–0.50 (0.0118–0.0197)
Side clearance mm (in) 0.04–0.08 (0.0015–0.0031)
Oversize diameter
1st mm (in) 80.250 (3.1594)
2nd mm (in) 80.500 (3.1693)
2nd piston ring
Dimension B mm (in) 1.97–1.99 (0.0776–0.0783)
Dimension T mm (in) 2.40–2.60 (0.0945–0.1024)
End gap mm (in) 0.30–0.50 (0.0118–0.0197)
Side clearance mm (in) 0.03–0.07 (0.0012–0.0028)
Oversize diameter
1st mm (in) 80.250 (3.1594)
2nd mm (in) 80.500 (3.1693)
Connecting rods
Small-end inside diameter mm (in) 24.900–24.912 (0.9803–0.9808)
Big-end side clearance mm (in) 0.200–0.700 (0.0079–0.0276)
Small-end axial play limit mm (in) 2.0 (0.08)
Crankshaft
Crankshaft width A mm (in) 63.90–63.95 (2.5157–2.5177)
Crankshaft width B mm (in) 40.88–41.10 (1.6094–1.6181)
Crankpin diameter mm (in) 26.995–27.000 (1.0628–1.0630)
Runout limit mm (in) 0.03 (0.0012)
40XWH 40XW E40XMH E40XW
Model
1
2
3
4
5
6
Thermostats
Opening temperature °C (°F) 48–52 (118–126)
Fully open temperature °C (°F) 60 (140)
Valve open lower limit mm (in) 3.0 (0.12)
Reed valves
Valve stopper height limit mm (in) 10.2–10.4 (0.40–0.41)
Valve bending limit mm (in) 0.2 (0.008)
66T5F11
7
8
9
2-4
Page 22
SPEC
Specifications
Item Unit
Carburetor
ID mark 66T02 66T12 66T02 66T12
Main jet # 170
Main air jet # 160
Pilot jet # 70
Pilot air jet # 60
Pilot screw turns out 1 3/8–1 7/8
Float height mm (in) 16.5–18.5 (0.65–0.73)
40XWH 40XW E40XMH E40XW
Model
Lower unit
Item Unit
Gear backlash
Pinion-to-forward gear mm (in) 0.19–0.56 (0.0075–0.0220)
Pinion-to-reverse gear mm (in) 0.75–1.13 (0.0295–0.0445)
Pinion shims mm 0.10, 0.12, 0.15, 0.18, 0.30, 0.40, 0.50
Forward gear shims mm 0.10, 0.12, 0.15, 0.18, 0.30, 0.40, 0.50
Reverse gear shims mm 0.10, 0.12, 0.15, 0.18, 0.30, 0.40, 0.50
40XWH 40XW E40XMH E40XW
Model
Electrical
Item Unit
Ignition and ignition control
system
Ignition timing (cylinder #1) Degree
Degree
Spark plug gap mm (in) 0.6–0.7 (0.024–0.028)
Spark plug cap resistance
(with resister type)
Ignition coil resistance
Primary coil (B/W – B)
at 20 °C (68 °F)
Secondary coil
(B/W – spark plug wire)
at 20 °C (68 °F) kΩ 5.4–7.4
CDI unit output peak voltage
(B/O – B, B/W – B)
at cranking (loaded) V 180
at 1,500 r/min (loaded) V 180
at 3,500 r/min (loaded) V 170
kΩ 4.0–6.0
Ω
0.32–0.44
40XWH 40XW E40XMH E40XW
ATDC2 at engine idle speed
BTDC23 at 5,000 r/min
Model
2-5
66T5F11
Page 23
Maintenance specification
Item Unit
Pulser coil output peak voltage
(W/R – W/B)
at cranking (unloaded) V 7.0
at cranking (loaded) V 4.0
at 1,500 r/min (loaded) V 10.0
at 3,500 r/min (loaded) V 17.0
Pulser coil resistance
Starter motor
Type Bendix — Bendix
Brushes
Length limit mm (in) 6.4 (0.25) — 6.4 (0.25)
Armature
Commutator undercut limit mm (in) 0.8 (0.03) — 0.8 (0.03)
Charging system
Fuse A 10
Charge coil output peak
voltage (Positive side: Br –
Negative side: L)
at cranking (unloaded) V 330
at cranking (loaded) V 190
at 1,500 r/min (loaded) V 190
at 3,500 r/min (loaded) V 190
Charge coil resistance (Br – L)
Lighting coil output peak
voltage
Lighting coil resistance
Rectifier output peak voltage
(*1)
The figures are for reference only.
(*1)
(G – G)
at cranking (unloaded) V 6.0 — 6.0
at 1,500 r/min (unloaded) V 16.0 — 16.0
at 3,500 r/min (unloaded) V 33.0 — 33.0
at 1,500 r/min (unloaded) V 14.0 — 14.0
at 3,500 r/min (unloaded) V 32.0 — 32.0
(*1)
(W/R – W/B)
(*1)
(G – G)
(R – B)
Ω
311.4–380.6
Ω
684–836
Ω
0.31–0.37 — 0.31–0.37
40XWH 40XW E40XMH E40XW
Model
1
2
3
4
5
6
7
8
66T5F11
9
2-6
Page 24
SPEC
Specifications
Dimensions
Exterior
* Tiller handle model only
mm (in)
45˚
221 (8.7)*
702 (27.6)
592 (23.3)* 369 (14.5)
159 (6.3)
523 (20.6)*
397 (15.6)
294 (11.6)*
118 (4.7)
190 (7.5)*
182 (7.2)
S: 826 (32.5)
L: 940 (37.0)
X:1,043 (41.1)
553 (21.8)
65 (2.6)
2-7
S: 424 (16.7)
X: 1,007 (39.7)
S: 767 (30.2)
L: 893 (35.2)
S: 25 (1.0)
L: 24 (0.9)
X: 24 (0.9)
L: 550 (21.7)
X: 664 (26.1)
175 (6.9) 471 (18.5)
43 (1.7)
38 (1.5)*
S: 65 (2.6)
L: 91 (3.6)
X: 91 (3.6)
S: 3 (0.1)
L: 8 (0.3)
X:16 (0.6)
12
˚
˚
4
522 (20.6)
64
˚
S: 626 (24.7)
L: 697 (27.4)
X: 761 (30.0)
S66T2010
66T5F11
Page 25
Clamp bracket
Maintenance specification
1
2
3
4
5
6
7
8
66T5F11
9
2-8
Page 26
SPEC
Specifications
Tightening torques
2
Specified torques
Part to be tightened Thread size
Fuel system
Intake silencer screw M6 2 0.2 1.5
Power unit
Power unit mounting bolt M8 21 2.1 15.5
Engine start button nut M16 5 0.5 3.7
Starter rope guide bolt M6 8 0.8 5.9
Manual starter roller bolt M6 3 0.3 2.2
Sheave drum bolt M6 5 0.5 3.7
Flywheel magnet nut M20 157 15.7 115.8
Starter motor bolt M8 21 2.1 15.5
Starter motor terminal nut M8 7 0.7 5.2
Starter relay terminal nut M6 4 0.4 3.0
Ignition coil bolt M6 8 0.8 5.9
Rectifier screw M5 3 0.3 2.2
Intake manifold bolt
1st
2nd 12 1.2 8.9
M6
Reed valve screw M5 2 0.2 1.5
Cylinder head bolt
Cylinder head cover bolt
Exhaust cover bolt
1st
2nd 30 3.0 22.1
1st
2nd 12 1.2 8.9
1st
2nd 12 1.2 8.9
M8
M6
M6
Spark plug — 25 2.5 18.4
Crankcase bolt
1st
2nd 40 4.0 29.5
M10
Lower unit
Gear oil drain screw — 90.96.6
Gear oil check screw — 90.96.6
Lower case mounting bolt M10 40 4.0 29.5
Cooling water inlet cover screw M5 4 0.4 3.0
Propeller nut M16 40 4.0 29.5
Propeller shaft housing bolt M8 16 1.6 11.8
Pinion nut M12 74 7.4 54.6
Tightening torques
N·mkgf·mft·lb
60.64.4
15 1.5 11.1
60.64.4
60.64.4
20 2.0 14.8
2-9
66T5F11
Page 27
Tightening torques
Part to be tightened Thread size
Bracket unit
Tiller handle bracket nut M10 10 1.0 7.4
Self-locking nut M10 41 4.1 30.2
Engine stop lanyard switch nut — 20.21.5
Battery lead holder screw M6 2 0.2 1.5
Throttle grip screw M5 3 0.3 2.2
Neutral switch nut — 70.75.2
Upper mounting nut M8 24 2.4 17.7
Upper mount bolt M8 27 2.7 20.0
Mount housing nut M10 54 5.4 39.8
Steering friction adjusting bolt M8 4 0.4 3.0
Upper case bolt M8 21 2.1 15.5
Exhaust manifold bolt M8 21 2.1 15.5
Self-locking nut M22 45 4.5 33.2
Tilt stopper plate nut M8 24 2.4 17.7
Grease nipple — 30.32.2
Clamp bracket nut M8 18 1.8 13.3
Tilt lever screw M5 4 0.4 3.0
Tightening torques
N·mkgf·mft·lb
1
2
3
4
General torques
This chart specifies tightening torques for
standard fasteners with a standard ISO
thread pitch. Tightening torque specifications
for special components or assemblies are
provided in applicable sections of this manual. To avoid warpage, tighten multi-fastener
assemblies in a crisscross fashion and progressive stages until the specified torque is
reached. Unless otherwise specified, torque
specifications require clean, dry threads.
Components should be at room temperature.
General torque
Nut (A) Bolt (B)
8 mm M5 5 0.5 3.6
10 mm M6 8 0.8 5.8
12 mm M8 18 1.8 13
14 mm M10 36 3.6 25
17 mm M12 43 4.3 31
specifications
N·mkgf·mft·lb
5
6
7
8
9
66T5F11
2-10
Page 28
SPEC
Specifications
— MEMO —
2-11
66T5F11
Page 29
CHK
ADJ
Periodic checks and adjustments
Special service tools .....................................................................................3-1
Maintenance interval chart............................................................................3-2
Top cowling ....................................................................................................3-3
Checking the top cowling...........................................................................3-3
Fuel system ....................................................................................................3-3
Checking the fuel joint and fuel hoses (fuel joint-to-carburetor) ................3-3
Checking the fuel filter ...............................................................................3-3
Power unit.......................................................................................................3-3
Checking the spark plugs ..........................................................................3-3
Checking the thermostat............................................................................3-4
Adjusting the start-in-gear protection.........................................................3-4
Checking the cooling water passage.........................................................3-5
Control system...............................................................................................3-5
Adjusting the ignition timing.......................................................................3-5
Adjusting the throttle cables (MH, WH) .....................................................3-6
Adjusting the throttle cable (W) .................................................................3-7
Checking the gear shift operation (MH, WH).............................................3-8
Checking the gear shift operation (W) .......................................................3-8
Checking the engine idle speed ................................................................3-9
Checking the ignition timing.....................................................................3-10
1
2
3
4
5
Bracket..........................................................................................................3-10
Checking the tilt operation .......................................................................3-10
Lower unit.....................................................................................................3-11
Checking the gear oil level ......................................................................3-11
Changing the gear oil ..............................................................................3-11
Checking the lower unit for air leakage ...................................................3-12
Checking the propeller.............................................................................3-12
General..........................................................................................................3-12
Checking the anodes...............................................................................3-12
Checking the battery................................................................................3-12
Lubricating the outboard motor................................................................3-13
6
7
8
9
66T5F11
Page 30
CHK
ADJ
Periodic checks and adjustments
Special service tools
Timing light
90890-03141
Digital tachometer
90890-06760
3
Leakage tester
90890-06840
3-1
66T5F11
Page 31
Special service tools / Maintenance interval chart
Maintenance interval chart
Use the following chart as a guideline for general maintenance.
Adjust the maintenance intervals according to the operating conditions of the outboard motor.
Item Remarks
Anodes (external) Check/replace
Anodes (internal) Check/replace
Battery Check/charge
Cooling water passages Clean
Top cowling Check
Fuel filter
(can be disassembled)
Fuel system Check
Fuel tank
(Yamaha portable tank)
Gear oil Change
Lubrication points Lubricate
Engine idle speed
(carburetor models)
Propeller and cotter pin Check/replace
Shift link/shift cable Check/adjust
Thermostat Check
Throttle link/throttle cable/
throttle pick-up timing
Water pump Check
Spark plugs Clean/adjust/
Check/replace
Check/clean
Check/adjust
Check/adjust
replace
Initial Every
10 hours
(1 month)
50 hours
(3 months)
100 hours
(6 months)
200 hours
(1 year)
Refer to
page
3
1
2
3
4
5
6
NOTE:
When operating in salt water, turbid or muddy water, the engine should be flushed with clean water
after each use.
66T5F11
3-2
7
8
9
Page 32
CHK
ADJ
Periodic checks and adjustments
Top cowling
Checking the top cowling
1. Check the fitting by pushing the cowling
with both hands.
S66T3010
2. Check the water separator drain holes for
obstructions. Clean if necessary.
3
Checking the fuel filter
1. Check the fuel filter element 1 for dirt
and residue and check the fuel filter cup
2
for foreign substances and cracks.
Clean the cup with straight gasoline and
replace the element if necessary.
NOTE:
Be sure not to spill any fuel when removing
the fuel filter cup.
Fuel system
Checking the fuel joint and fuel
hoses (fuel joint-to-carburetor)
1. Check the fuel hose connections and fuel
joints for leaks. Replace if necessary.
Also, check the fuel filter 1, fuel pump
2
, and carburetor 3 for leaks or deterio-
ration. Replace if necessary.
1
3
Power unit
3
Checking the spark plugs
1. Disconnect the spark plug caps, and then
remove the spark plugs.
2. Clean the electrodes 1 with a spark plug
3
cleaner or wire brush. Replace the spark
plug if necessary.
3. Check the electrodes for erosion and
excessive carbon or other deposits, and
the gasket for damage. Replace the
spark plug if necessary.
3-3
2
S66T3030
4. Check the spark plug gap a. Adjust if out
of specification.
66T5F11
Page 33
Specified spark plug:
B7HS (NGK), BR7HS (NGK)
Spark plug gap a:
0.6–0.7 mm (0.024–0.028 in)
5. Install the spark plugs, tighten them finger tight, then to the specified torque
using a spark plug wrench.
Top cowling / Fuel system / Power unit
1
S69J5E40
2
4. Check the thermostat valve opening at
the specified water temperatures.
Replace if out of specification.
3
Spark plug:
T
.
R
.
25 N·m (2.5 kgf·m, 18.4 ft·lb)
Checking the thermostat
1. Remove the cover 1 and thermostat 2.
2
1
2. Suspend the thermostat in a container of
water.
3. Place a thermometer in the water and
slowly heat the water.
S66T3040
Water
temperature
48–52 °C
(118–126 °F)
above
60 °C (140 °F)
5. Install the thermostat and cover, and
then tighten the cover bolts.
Adjusting the start-in-gear
protection
1. Set the gear shift to the neutral position.
Valve lift a
0.05 mm
(0.0020 in)
(valve begins to lift)
more than
3.0 mm (0.12 in)
4
5
6
7
8
66T5F11
9
3-4
Page 34
CHK
ADJ
Periodic checks and adjustments
2. Loosen the lock nut 1, and then adjust
the start-in-gear protection adjusting nut
2
until the point a on the wire connector
aligned with the mark b on the manual
starter case.
Checking the cooling water passage
1. Check the cooling water inlet cover
and cooling water inlet for clogs. Clean if
necessary.
1
1
Control system
Adjusting the ignition timing
1. Make sure that the engine is stopped
before adjusting the ignition timing.
2. Loosen the throttle cables or remove the
remote control cable.
3. Turn the flywheel magnet clockwise so
that ATDC 2° line a aligns with the mark
b
on the manual starter case.
4. Loosen the locknut 1.
5. Turn the throttle control lever 2 so that
the full-retard screw 3 contacts the stopper 4.
6. Adjust the full-retard screw 3 so that the
timing indicator c aligns with the mark
d
on the flywheel magnet.
7. Tighten the locknut 1.
3
1
S66T3230
2. Place the lower unit in water, and then
start the engine.
3. Check for water flow at the cooling water
pilot hole. If there is no water flow, check
the cooling water passage inside the outboard motor.
8. Adjust the throttle cables or remote control cable.
3-5
S66T3050
66T5F11
Page 35
9. Shift the remote control lever or shift
lever to forward or reverse, and then
check that the stopper 5 on the throttle
control lever contacts the stopper 6 on
the throttle cable bracket when the throttle is fully open.
10. Start the engine and warm it up for 5 minutes.
11. Check the ignition timing with a timing
light and, if necessary, repeat steps 1–
10.
Power unit / Control system
1
2
6. Turn the throttle grip to the fully closed
position.
7. Loosen the locknut 5.
3
8. Contact the full-retard screw 7 to the
stopper 8, and then turn the adjusting
nut 6 in or out until the specified throttle
cable free play is obtained.
4
9. Tighten the locknut 5.
Ignition timing at engine idle speed:
ATDC 2°
Adjusting the throttle cables
(MH, WH)
NOTE:
Before adjusting the throttle cables, the throttle stop screw should be properly adjusted.
1. Loosen the locknut 1.
2. Loosen the throttle-cam-roller adjusting
screw (left-hand threads) 2.
3. Turn the throttle grip to the fully open
position.
4. Adjust the throttle cable adjusting nut
until the center of the throttle cam roller
4
aligns with the mark a on the throttle
cam.
3
5
6
Throttle cable free play:
1 mm (0.04 in)
7
8
9
5. Tighten the locknut.
66T5F11
3-6
Page 36
CHK
ADJ
10. Align the center of the throttle cam roller
4
with the mark b on the throttle cam,
and then tighten the throttle-cam-roller
adjusting screw 1.
11. Check that the center of the throttle cam
roller 4 aligns with the mark a on the
throttle cam when the throttle grip is
turned to the fully open position.
12. Check that the full-retard screw 7 contacts the stopper 8 and that the center of
the throttle cam roller 4 is aligned with
the mark b on the throttle cam when the
throttle grip is turned to the fully closed
position.
Periodic checks and adjustments
5. Adjust the position of the throttle cable
joint until its hole is aligned with the set
pin on the throttle control lever.
13. If necessary, repeat steps 1–12.
Adjusting the throttle cable (W)
NOTE:
Before adjusting the throttle cable, the throttle stop screw should be properly adjusted.
1. Loosen the locknut 1, remove the clip
2
, and then disconnect the throttle cable
joint 3.
2. Set the remote control lever to the neutral position.
3. Loosen the throttle-cam-roller adjusting
screw (left-hand threads) 4.
4. Check that the full-retard screw 5 contacts the stopper 6 and that the center of
the throttle cam roller 7 is aligned with
the mark a on the throttle cam.
b
S66T1050
WARNING
The throttle cable joint must be screwed
in a minimum of 8.0 mm (0.31 in) b.
6. Connect the cable joint, install the clip,
and then tighten the locknut.
7. Align the center of the throttle cam roller
7
with the mark a on the throttle cam,
and then tighten the throttle-cam-roller
adjusting screw 4.
3-7
66T5F11
Page 37
8. Check that the stopper 8 on the throttle
control lever contacts the stopper 9 on
the throttle cable bracket and that the
center of the throttle cam roller 7 is
aligned with the mark c on the throttle
cam when the remote control lever is
fully open position.
Control system
1
S66T3290
2. Set the gear shift to the neutral position.
3. Check that the neutral switch lever 2 on
the shift lever assembly is pushing the
neutral switch 3. (WH)
N
1
2
3
9. Check that the full-retard screw 5 contacts the stopper 6 and that the center of
the throttle cam roller 7 is aligned with
the mark a on the throttle cam when the
remote control lever is fully closed position.
10. If necessary, repeat steps 1–9.
Checking the gear shift operation
(MH, WH)
1. Check that the gear shift operates
smoothly when shifting it from neutral to
forward or reverse. Adjust the adjusting
nut 1 if necessary.
R
N
F
R
F
Checking the gear shift operation
(W)
1. Check that the gear shift operates
smoothly when shifting it from neutral to
forward or reverse. Adjust the shift cable
length if necessary.
2. Set the gear shift to the neutral position.
3
2
S66T3260
4
5
6
7
8
66T5F11
S66T3250
9
3-8
Page 38
CHK
ADJ
3. Loosen the locknut 1, remove the clip
2
, and then disconnect the shift cable
joint 3.
4. Set the shift lever 4 to the neutral position.
Periodic checks and adjustments
N
R
F
6
23
R
N
F
1
4
S66T3220
5. Adjust the position of the shift cable joint
until its hole is aligned with the set pin.
a
S6D53190
5
S66T3270
Checking the engine idle speed
1. Start the engine and warm it up for 5 minutes.
2. Attach the special service tool to spark
plug wire #1 1, and then check the
engine idle speed. Adjust if out of specification.
1
S66T3060
WARNING
The shift cable joint must be screwed in a
minimum of 8.0 mm (0.31 in) a.
6. Connect the cable joint, install the clip,
and then tighten the locknut.
7. Check the gear shift for smooth operation
and, if necessary, repeat steps 2–6.
8. Check that the neutral switch lever on the
shift lever assembly 5 is pushing the
neutral switch 6. (if equipped)
Digital tachometer: 90890-06760
Engine idle speed: 950–1,050 r/min
3. Turn the throttle stop screw 2 in direction a or b until the specified engine
idle speed is obtained.
3-9
66T5F11
Page 39
Control system / Bracket
NOTE:
• To increase the idle speed, turn the throttle
stop screw in direction a.
• To decrease the idle speed, turn the throttle
stop screw in direction b.
4. If the specified engine idle speed cannot
be obtained, adjust the throttle cable(s).
Checking the ignition timing
1. Start the engine and warm it up for 5 min-
utes.
2. Attach the special service tool to spark
plug wire #1 1, and then check the
engine idle speed.
4. Check that the ATDC 2° line a on the
flywheel magnet is aligned with the mark
b
on the manual starter case. Adjust if
out of specification.
a
b
S66T3100
Ignition timing at engine idle speed:
ATDC 2°
Bracket
Checking the tilt operation
1. Fully tilt the outboard motor up and down
a few times and check the entire tilt
range for smooth operation.
1
2
3
3
4
1
S66T3060
Digital tachometer: 90890-06760
Engine idle speed: 950–1,050 r/min
3. Attach the special service tool to spark
plug wire #1 1.
1
S66T3090
5
6
7
8
S66T3300
9
66T5F11
Timing light: 90890-03141
3-10
Page 40
CHK
ADJ
Periodic checks and adjustments
Lower unit
Checking the gear oil level
1. Fully tilt the outboard motor down.
2. Remove the check screw 1, and then
check the gear oil level in the lower case.
1
S60V3320
NOTE:
If the oil is at the correct level, the oil should
overflow out of the check hole when the
check screw is removed.
3. If necessary, add sufficient gear oil of the
recommended type until it overflows out
of the check hole.
3
3. Check the oil for metal and discoloration,
and its viscosity. Check the internal parts
of the lower case if necessary.
4. Insert a gear oil tube or gear oil pump
into the drain hole and slowly fill the gear
oil until oil flows out of the check hole and
no air bubbles are visible.
Recommended gear oil:
Hypoid gear oil
API: GL-4
SAE: 90
4. Install the check screw.
Changing the gear oil
1. Tilt the outboard motor up slightly.
2. Place a drain pan under the drain screw
1
, remove the drain screw, then the
check screw 2 and let the oil drain completely.
Recommended gear oil:
Hypoid gear oil
API: GL-4
SAE: 90
Oil quantity:
430 cm
3
(14.54 US oz, 15.17 Imp oz)
5. Install the check screw and quickly install
the drain screw.
3-11
66T5F11
Page 41
Lower unit / General
Checking the lower unit for air
leakage
1. Remove the check screw 1, and then
install the special service tool.
Leakage tester: 90890-06840
2. Apply the specified pressure to check
that the pressure is maintained in the
lower unit for at least 10 seconds.
CAUTION:
Do not over pressurize the lower unit, otherwise the oil seals can be damaged.
NOTE:
Cover the check hole with a rag when removing the special service tool from the lower
unit.
General
Checking the anodes
1. Check the anodes and trim tab for
scales, grease, or oil. Clean if necessary.
CAUTION:
Do not oil, grease, or paint the anodes or
the trim tab, otherwise they will be ineffective.
2. Replace the anodes or trim tab if excessively eroded.
Checking the battery
1. Check the battery electrolyte level. If the
level is at or below the minimum level
mark a, add distilled water until the level
is between the maximum and minimum
level marks.
3
1
2
3
4
5
6
Lower unit holding pressure:
100 kPa (1.0 kgf/cm
3. If pressure drops below specification,
check the drive shaft and propeller shaft
oil seals for damage.
Checking the propeller
1. Check the propeller blades and splines
for cracks, damage, or wear. Replace if
necessary.
66T5F11
2
, 14 psi)
a
7
S69J3620
8
9
3-12
Page 42
CHK
ADJ
Periodic checks and adjustments
2. Check the specific gravity of the electrolyte. Fully charge the battery if below
specification.
WARNING
Battery electrolyte is dangerous; it contains sulfuric acid which is poisonous and
highly caustic.
Always follow these preventive measures:
• Avoid bodily contact with electrolyte as
it can cause severe burns or permanent
eye injury.
• Wear protective eye gear when handling
or working near batteries.
Antidote (EXTERNAL):
• SKIN – Wash with water.
• EYES – Flush with water for 15 minutes
and get immediate medical attention.
Antidote (INTERNAL):
• Drink large quantities of water or milk
followed with milk of magnesia, beaten
egg, or vegetable oil. Get immediate
medical attention.
Batteries generate explosive, hydrogen
gas. Always follow these preventive measures:
• Charge batteries in a well-ventilated
area.
• Keep batteries away from fire, sparks or
open flames (e.g., welding equipment,
lighted cigarettes).
• DO NOT SMOKE when charging or han-
dling batteries.
KEEP BATTERIES AND ELECTROLYTE
OUT OF REACH OF CHILDREN.
Lubricating the outboard motor
1. Apply water resistant grease to the areas
shown.
AA
S66T3200
AA
S66T3210
È
A
NOTE:
• Batteries vary per manufacturer. The procedures mentioned in this manual may not
always apply, therefore, consult the instruction manual of the battery.
• Disconnect the negative battery lead first,
then the positive battery lead.
Electrolyte specific gravity:
1.280 at 20 °C (68 °F)
3-13
S6D53290
66T5F11
Page 43
È
Tiller handle model
È
NOTE:
Apply grease to the grease nipples until it
flows from the bushings a.
2. Apply low temperature resistant grease
to the area shown.
General
1
2
3
3. Apply corrosion resistant grease to the
area shown.
4
5
6
7
8
66T5F11
9
3-14
Page 44
CHK
ADJ
Periodic checks and adjustments
— MEMO —
3-15
66T5F11
Page 45
FUEL
Fuel system
Special service tools .....................................................................................4-1
Hose routing...................................................................................................4-2
Fuel line ..........................................................................................................4-3
Fuel pump.......................................................................................................4-5
Checking the fuel pump.............................................................................4-6
Disassembling the fuel pump ....................................................................4-6
Assembling the fuel pump .........................................................................4-7
Checking the fuel joint ...............................................................................4-7
Carburetor.......................................................................................................4-8
Disassembling the carburetor..................................................................4-10
Checking the carburetor ..........................................................................4-10
Assembling the carburetor.......................................................................4-11
Adjusting the throttle stop screw..............................................................4-11
1
2
3
4
5
6
7
8
9
66T5F11
Page 46
FUEL
Fuel system
Special service tools
Vacuum/pressure pump gauge set
90890-06756
4
4-1
66T5F11
Page 47
Special service tools / Hose routing
Hose routing
1
4
1
2
3
4
3
4
1
Fuel hose (fuel joint-to-fuel filter)
1
Fuel hose (fuel filter-to-fuel pump)
2
Fuel hose (fuel pump-to-carburetor)
3
Pilot water hose
4
3
2
5
4
6
7
S66T4010
8
66T5F11
9
4-2
Page 48
FUEL
Fuel system
Fuel line
4
No. Part name Q’ty Remarks
1 Clamp 6
2 Fuel hose 1
3Bolt 1 M6 × 30 mm
4 Fuel joint 1
5Grommet 1
6 Fuel hose 1
7 Fuel hose 1
8Bolt 2 M6 × 40 mm
9 Fuel pump 1
10 Gasket 1
11 Nut 1
12 Bolt 1 M6 × 14 mm
13 Bracket 1
14 Fuel filter assembly 1
15 Fuel filter element 1
16 O-ring 1
17 Cup 1
Not reusable
Not reusable
4-3
66T5F11
Page 49
Fuel line
4
1
2
3
No. Part name Q’ty Remarks
18 Screw 2 ø6 × 40 mm
19 Collar 2
20 Intake silencer 1
21 O-ring 1
22 Bolt 2 M8 × 100 mm
23 Carburetor 1
24 O-ring 1
25 Solenoid coil 1 W model
26 Bracket 1 W model
27 Grommet 1 W model
28 Spring 1 W model
29 O-ring 1
30 Hook 1 W model
31 Screw 4 W model
32 Bolt 3 M6 × 25 mm / W model
33 Grommet 3 W model
34 Collar 3 W model
Not reusable
Not reusable
Not reusable
W model
4
5
6
7
8
9
66T5F11
4-4
Page 50
FUEL
Fuel system
Fuel pump
4
No. Part name Q’ty Remarks
1Screw 3 ø5 × 30 mm
2 Cover 1
3 Diaphragm 1
4Gasket 1
5 Fuel pump body assembly 1
6Gasket 2
7 Diaphragm 1
8 Cover 1
Not reusable
Not reusable
4-5
66T5F11
Page 51
Fuel pump
Checking the fuel pump
1. Place a drain pan under the fuel hose
connections, and then disconnect the
fuel hoses from the fuel pump.
2. Connect the special service tool to the
fuel pump inlet.
3. Cover the fuel pump outlet with a finger,
and then apply the specified positive
pressure. Check that there is no air leakage.
6. Apply the specified positive pressure and
check that there is no air leakage. Disassemble the fuel pump if necessary.
NOTE:
Assemble the fuel pump valves to the fuel
pump body, and moisten the inside of the fuel
pump with gasoline to ensure a good seal.
Specified pressure:
50 kPa (0.5 kgf/cm
2
, 7.3 psi)
1
2
3
4
Vacuum/pressure pump gauge set:
90890-06756
Specified pressure:
50 kPa (0.5 kgf/cm
4. Apply the specified negative pressure
and check that there is no air leakage.
Specified pressure:
30 kPa (0.3 kgf/cm
5. Connect the special service tool to the
fuel pump outlet.
2
, 7.3 psi)
2
, 4.4 psi)
Disassembling the fuel pump
1. Disassemble the fuel pump.
2. Check the diaphragms for tears or damage. Replace if necessary.
3. Check the valves for bends or damage.
Replace if necessary. Also, check the
fuel pump body for damage. Replace if
necessary.
4. Clean the fuel pump body.
5
6
7
8
9
66T5F11
4-6
Page 52
FUEL
Fuel system
Assembling the fuel pump
NOTE:
Clean the parts and soak the valves and the
diaphragms in gasoline before assembly to
obtain prompt operation of the fuel pump
when starting the engine.
1. Install the valves 1 onto the fuel pump
body.
2. Install new gaskets 2, the diaphragms
3
, and covers 4.
Checking the fuel joint
1. Visually check the fuel joint for cracks or
damage.
2. Connect the special service tool at the
outlet of fuel joint.
3. Apply the specified pressure to check
that the pressure is maintained for 10
seconds. Replace the fuel joint if necessary.
Vacuum/pressure pump gauge set:
90890-06756
NOTE:
Make sure that the gaskets and diaphragms
are kept in place through the assembly process.
Fuel joint holding pressure:
50 kPa (0.5 kgf/cm
2
, 7.3 psi)
4-7
66T5F11
Page 53
Fuel pump / Carburetor
Carburetor
4
1
2
3
4
No. Part name Q’ty Remarks
1Screw 4 ø4 × 10 mm
2 Cover 1
3Gasket 1
4 Throttle stop screw 1
5Spring 1
6 Pilot screw 1
7Spring 1
8Screw 1 ø5 × 10 mm
9 Washer 1
10 Screw 4 ø5 × 25 mm
11 Float chamber 1
12 O-ring 1
13 Drain screw 1
14 Gasket 1
15 Carburetor body 1
16 Gasket 1
17 Carburetor body 1
Not reusable
Not reusable
Not reusable
5
6
7
8
9
66T5F11
4-8
Page 54
FUEL
Fuel system
4
No. Part name Q’ty Remarks
18 Pilot jet 1
19 Plug 1
20 Main jet 1
21 Washer 1
22 Float pin 1
23 Float 1
24 Needle valve 1
4-9
66T5F11
Page 55
Disassembling the carburetor
1. Remove the pilot screw.
NOTE:
Before disassembling the carburetor, make
sure to note the number of times the pilot
screw is turned out from the seated position
to its set position.
2. Remove the float chamber, float pin 1,
float 2, and needle valve 3.
Carburetor
CAUTION:
• Direct the compressed air downward,
otherwise cleaning solvent may be
blown into your eyes or small parts of
the carburetor may be blown off.
• Do not use steel wire for cleaning the
jets, otherwise the jet diameters may be
enlarged, which may seriously affect
performance.
3. Check the main jet, pilot jet, and main
nozzle for dirt or residue. Clean if necessary.
4. Check the pilot screw and needle valve
for bends or wear. Replace if necessary.
1
2
3
NOTE:
Remove the float pin 1 in the direction of the
arrow a shown.
3. Remove the jets and other components.
Checking the carburetor
1. Check the air and fuel passages and jets,
for dirt and foreign matter. Clean the carburetor body with a petroleum based solvent if necessary.
2. Blow compressed air into all passages
and jets.
S6D54200
5. Check the float for deterioration. Replace
if necessary.
4
5
6
7
8
66T5F11
9
4-10
Page 56
FUEL
Fuel system
6. Measure the float height a. Replace the
float and needle valve as a set, if out of
specification.
NOTE:
• The float should be resting on the needle
valve 1, but not compressing it.
• Take measurements at the float position
shown opposite its pivoted side.
Float height a:
16.5–18.5 mm (0.65–0.73 in)
Assembling the carburetor
1. Install the main jet 1, pilot jet 2, and
plug 3 to the carburetor body as shown.
NOTE:
• Install the float pin 6 in the direction of the
arrow a shown.
• Place the needle valve in the valve seat
when installing the float to the carburetor
body.
3. Install the pilot screw, turn it in until it is
lightly seated, then out the specified
number of turns.
NOTE:
• Adjust the throttle cable whenever the carburetor has been disassembled or the
engine idle speed has been adjusted.
• For adjustment procedures, see Chapter 3.
2. Install the needle valve 4, float 5, and
float pin 6, as shown, and then the
check the float for smooth operation.
Pilot screw setting:
1 3/8–1 7/8 turns out
4. Install the carburetor assembly.
Adjusting the throttle stop screw
1. Start the engine and warm it up for 5 minutes.
2. Turn the throttle stop screw 1 in direction a or b until the specified engine
idle speed is obtained.
4-11
66T5F11
Page 57
Carburetor
1
NOTE:
• To increase the idle speed, turn the throttle
stop screw in direction a.
• To decrease the idle speed, turn the throttle
stop screw in direction b.
Engine idle speed: 950–1,050 r/min
3. If the specified engine idle speed cannot
be obtained, adjust the throttle cable(s).
2
3
4
5
6
66T5F11
7
8
9
4-12
Page 58
FUEL
Fuel system
— MEMO —
4-13
66T5F11
Page 59
POWR
Power unit
Special service tools .....................................................................................5-1
Power unit.......................................................................................................5-4
Checking the compression pressure .........................................................5-4
Disassembling the manual starter ........................................................... 5-13
Checking the spiral spring .......................................................................5-13
Checking the drive pawl ..........................................................................5-13
Measuring the starter rope ......................................................................5-14
Assembling the manual starter ................................................................5-14
Removing the power unit.........................................................................5-15
Removing the flywheel magnet ...............................................................5-16
Removing the electrical components.......................................................5-17
Removing the throttle cam assembly ......................................................5-18
Disassembling the base assembly ..........................................................5-18
Assembling the base assembly ...............................................................5-18
Reed valves ..................................................................................................5-19
Removing the reed valve assembly.........................................................5-20
Checking the reed valve ..........................................................................5-20
Cylinder head ...............................................................................................5-21
Removing the cylinder head ....................................................................5-22
Checking the cylinder head .....................................................................5-22
Removing the exhaust cover ...................................................................5-22
Checking the exhaust cover .................................................................... 5-22
1
2
3
4
5
Crankcase.....................................................................................................5-23
Removing the crankcase and oil seal housing ........................................5-26
Removing the crankshaft assembly.........................................................5-26
Checking the cylinder bore ......................................................................5-26
Disassembling the oil seal housing .........................................................5-27
Checking the oil seal housing..................................................................5-27
Assembling the oil seal housing ..............................................................5-27
Disassembling the piston.........................................................................5-27
Checking the piston diameter ..................................................................5-27
Checking the piston clearance ................................................................5-28
Checking the piston rings ........................................................................5-28
Checking the piston ring side clearance..................................................5-28
Checking the piston pin boss bore ..........................................................5-29
Checking the piston pin ...........................................................................5-29
Disassembling the crankshaft..................................................................5-29
Checking the crankpin .............................................................................5-31
Assembling the crankshaft ......................................................................5-31
Checking the crankshaft ..........................................................................5-34
Installing the crankshaft bearings ............................................................5-35
Assembling the piston .............................................................................5-35
Assembling the power unit ......................................................................5-36
Installing the power unit...........................................................................5-38
6
7
8
9
66T5F11
Page 60
POWR
Power unit
Special service tools
Compression gauge
90890-03160
Flywheel holder
90890-06522
5
Driver rod LS
90890-06606
Bearing separator
90890-06534
Flywheel puller
90890-06521
Needle bearing attachment
90890-06613, 90890-06654, 90890-06655
Driver rod L3
90890-06652
Plate C
90890-02402
Pressure pin C
90890-02403
Support
90890-02394
5-1
66T5F11
Page 61
Special service tools
1
Pressure pin B
90890-02390
Spacer C
90890-02404
Bushing-9 (D30)
90890-02363
Bolt
90890-02353
2
C
3
Washer
90890-02354
4
5
Height ring-640 (H19)
90890-06590
Body
90890-02352
Flange
90890-02351
Bushing-12 (D35)
90890-02366
Pressure plate
90890-02384
6
7
8
9
66T5F11
5-2
Page 62
POWR
Press body
90890-02385
Bearing pressure C
90890-02393
Power unit
Small end bearing installer
90890-06527
5-3
66T5F11
Page 63
Special service tools / Power unit
Power unit
Checking the compression pressure
1. Start the engine, warm it up for 5 min-
utes, and then turn it off.
2. Remove the clip from the engine stop
lanyard switch.
3. Remove the spark plug caps and all
spark plugs, and then install the special
service tools into a spark plug hole.
S66T5110
5
5. If the compression pressure is below
specification and the compression pressure for each cylinder is unbalanced, add
a small amount of engine oil to the cylinders, and then check the compression
pressure again.
NOTE:
• If the compression pressure increases,
check the pistons and piston rings for wear.
Replace if necessary.
• If the compression pressure does not
increase, check the cylinder head gasket,
and cylinder head. Replace if necessary.
1
2
3
4
CAUTION:
Before removing the spark plugs, blow
compressed air in the spark plug well to
clear out any dirt or dust that may fall into
the cylinder.
Compression gauge: 90890-03160
4. Fully open the throttle, and then crank
the engine until the reading on the compression gauge stabilizes.
NOTE:
Do not pull the choke knob when checking
the compression pressure.
Minimum compression pressure
(reference data):
630 kPa (6.3 kgf/cm
2
, 91 psi)
5
6
7
8
66T5F11
9
5-4
Page 64
POWR
Power unit
No. Part name Q’ty Remarks
1 Power unit 1
2 Manual starter 1
3 Collar 3
4Grommet 6
5Bolt 1 M8 × 25 mm
6Bolt 2 M8 × 35 mm
7Gasket 1
8Bolt 2 M6 × 16 mm
9 Dowel 2
10 Apron 1
11 Bolt 2 M6 × 16 mm
12 Bolt 6 M8 × 80 mm
13 Bolt 2 M8 × 30 mm
Not reusable
5-5
66T5F11
Page 65
Power unit
5
1
2
3
No. Part name Q’ty Remarks
1 Flywheel magnet 1
2 Base assembly 1
3Bolt 4 M6 × 40 mm
4Link rod 1
5 Oil seal 1
6O-ring 1
7 Woodruff key 1
8Bolt 3 M6 × 40 mm
9 Starter pulley 1
10 Nut 1
11 Washer 1
12 Corrugated tube 1 WH and W models
13 Cover 1
14 Bolt 1 M6 × 16 mm
15 Bolt 1 M6 × 25 mm
16 Retainer 1
17 Pulser coil assembly 1
Not reusable
Not reusable
4
5
6
7
8
9
66T5F11
5-6
Page 66
POWR
Power unit
5
No. Part name Q’ty Remarks
18 Charge coil 2
19 Lighting coil 1
20 Screw 6 M6 × 25 mm
21 Screw 5 M4 × 6 mm
5-7
66T5F11
Page 67
Power unit
5
1
2
3
No. Part name Q’ty Remarks
1 Starter motor 1
2 Starter relay 1
3 Holder 1
4Bracket 1
5Bracket 1
6Bolt 1 M6 × 16 mm
7Cap 2
8Nut 1
9 Spring washer 1
10 Starter motor lead 1
11 Bolt 1 M8 × 75 mm
12 Nut 1
13 Bolt 2 M8 × 50 mm
All components are for WH and W models only.
4
5
6
7
8
9
66T5F11
5-8
Page 68
POWR
Power unit
5
T
.
R
.
T
.
R
.
3 N
8 N
m (0.3 kgf
·
15
8
m (0.8 kgf
·
m, 2.2 ft
·
m, 5.9 ft
·
1
10
Ib)
·
·
Ib)
2
13
12
11
14
9
3
7
5
4
T
.
R
.
8 N
m (0.8 kgf
·
m, 5.9 ft
·
Ib)
·
15
6
8
No. Part name Q’ty Remarks
1Screw 1 ø5 × 30 mm / WH and W models
2 Rectifier 1 WH and W models
3 Nut 1 WH and W models
4Grommet 3
5 Collar 3
6 Ignition coil #1 1
7Bolt 1 M6 × 12 mm
8Bolt 4 M6 × 25 mm
9 CDI unit 1
10 Bolt 2 M6 × 25 mm
11 Bolt 3 M6 × 30 mm
12 Bolt 1 M6 × 16 mm
13 Ignition coil #2 1
14 Bracket 1
15 Spark plug cap 2
S66T5050
5-9
66T5F11
Page 69
Power unit
5
1
2
3
No. Part name Q’ty Remarks
1Bolt 1 M8 × 45 mm
2 Washer 1
3 Collar 1
4 Throttle control lever 1
5Spring 1
6 Throttle cam 1
7Bolt 1 M6 × 14 mm
8Bracket 1
9Screw 1
10 Spring 1
11 Nut 1
12 Cap 1
4
5
6
7
8
66T5F11
9
5-10
Page 70
POWR
Power unit
5
No. Part name Q’ty Remarks
1 Manual starter case 1
2Spiral spring 1
3 E-clip 1
4 Sheave drum 1
5 Drive pawl 1
6Spring 1
7Drive plate 1
8Bolt 1 M6 × 16 mm
9Spring 1
10 Spring 1
11 Bolt 2 M6 × 35 mm
12 Collar 2
13 Bolt 1 M6 × 25 mm
14 Washer 1
15 Collar 1
16 Roller 1
17 Engine start button assembly 1 WH model
5-11
66T5F11
Page 71
Power unit
5
1
2
3
No. Part name Q’ty Remarks
18 Grommet 1 MH and W models
19 Cover 1
20 Manual starter handle 1
21 Damper 1
22 Starter rope 1
23 Starter rope guide 1
24 Start-in-gear protection cable 1
25 Stopper 1
26 Spring 1
27 Spring 1
28 Holder 1 WH and W models
4
5
6
7
8
66T5F11
9
5-12
Page 72
POWR
Power unit
Disassembling the manual starter
1. Turn the sheave drum 1 clockwise until
the spiral spring is free.
NOTE:
• Turn the sheave drum so that the notch on
the outer surface of the sheave drum faces
toward the manual starter handle.
• Pass the starter rope 2 through the notch
a
.
2. Remove the drive plate 3 and spring 4.
WARNING
The spiral spring can pop out. Cover the
spiral spring with cloths, then pull out the
sheave drum.
4. Remove the spiral spring 6 from the
manual starter case.
WARNING
The spiral spring can pop out. To remove
the spring, cover it with cloths.
WARNING
The sheave drum can pop out. Hold the
sheave drum with your hand, then pull it
out.
NOTE:
Insert a flathead screwdriver into the hole
in the sheave drum and push down on the
spiral spring so that it releases from the
sheave drum.
3. Remove the sheave drum 5.
b
5. Remove the starter rope 7.
6. Remove the drive pawl 8 and springs
from the sheave drum.
9
7
9
8
S66T5200
Checking the spiral spring
1. Check the spiral spring for cracks, bends,
or damage. Replace if necessary.
Checking the drive pawl
1. Check the drive pawl for cracks or damage. Replace if necessary.
5-13
66T5F11
Page 73
Measuring the starter rope
1. Measure the starter rope length. Replace
if the length is below specification.
Power unit
Starter rope length:
1,750 mm (68.9 in)
Assembling the manual starter
1. Install the starter rope 1 to the sheave
drum 2.
2. Install the drive pawl and springs.
3. Install the manual starter handle 3.
b
S66T5220
NOTE:
After winding the starter rope around the
sheave drum, install the starter rope in the
notch b.
5. Install the spiral spring 4 into the starter
case.
d
c
1
2
3
4
5
NOTE:
• Tie a knot at the end of the starter rope as
shown in the illustration.
• Be sure to leave 7–12 mm (0.28–0.47 in) at
the end a of the starter rope.
4. Wind the starter rope twice around the
sheave drum in the direction of the arrow
shown in the illustration.
4
S66T5230
NOTE:
Install the outer end c of the spiral spring
onto the pin d of the starter case.
6. Install the sheave drum into the manual
starter case 5.
5
AA
S66T5240
NOTE:
Install the sheave drum, then set the spiral
spring by turning the sheave drum.
6
7
8
9
66T5F11
5-14
Page 74
POWR
Power unit
7. Install the spring 6 and drive plate 7.
8. Turn the sheave drum 3 times in the
direction of the arrow shown, and then
remove the starter rope from the notch
e
.
10. Pull the manual starter handle completely, then measure the starter rope
length. Adjust if the starter rope length is
out of specification.
f
S66T5270
Starter rope length f:
1,400–1,600 mm (55.1–63.0 in)
Removing the power unit
NOTE:
It is recommended to loosen the flywheel
magnet nut before removing the power unit to
improve working efficiency.
NOTE:
Hold the stopper 8 while turning the sheave
drum as shown.
9. Pull the manual starter handle several
times to check that the sheave drum
turns smoothly and to check the starter
rope for slack. Repeat steps 4–8 if necessary.
S66T5260
1. Disconnect the engine starter button connectors 1 (WH model).
2. Disconnect the start-in-gear protection
cable 2, and then remove the manual
starter 3.
3. Remove the intake silencer.
5-15
66T5F11
Page 75
Power unit
4. Disconnect the choke link rod 4.
4
S66T5130
5. Disconnect the remote control cables
(remote control model) or throttle cables
(tiller handle model).
6. Disconnect the battery leads and neutral
switch connectors (WH and W models).
7. Remove the cover, and then disconnect
the engine stop lanyard switch leads
(MH and WH models).
5
Removing the flywheel magnet
1. Remove the starter pulley, and then
loosen the flywheel magnet nut.
S66T5920
CAUTION:
Apply force in the direction of the arrows
shown, to prevent the flywheel holder
from slipping off easily.
Flywheel holder: 90890-06522
1
2
3
4
8. Disconnect the fuel hose and pilot water
hose.
9. Remove the apron 6, and then remove
the power unit by removing the bolts.
5
6
7
8
9
66T5F11
5-16
Page 76
POWR
Power unit
2. Remove the flywheel magnet.
3. Disconnect the starter motor lead from
the starter motor (WH and W models).
4. Disconnect the starter relay leads.
S60V5470
CAUTION:
To prevent damage to the engine or tools,
screw in the flywheel puller set bolts
evenly and completely so that the flywheel puller plate is parallel to the flywheel magnet.
NOTE:
Apply force to the crankshaft end until the flywheel magnet comes off the tapered portion
of the crankshaft.
Flywheel puller: 90890-06521
3. Remove the Woodruff key.
Removing the electrical components
1. Disconnect the pulser coil and charge
coil coupler 1, and disconnect the lighting coil connectors 2 (WH and W models).
5. Remove the starter motor 4 and starter
relay 5 (WH and W models).
5
4
S66T5390
2. Remove the base assembly 3.
5-17
66T5F11
Page 77
Power unit
6. Remove the spark plug caps 6 from the
spark plugs.
7. Disconnect the thermoswitch connectors
7
and ground lead 8, and then remove
the CDI unit assembly 9.
Removing the throttle cam assembly
1. Remove the throttle cam assembly.
Assembling the base assembly
1. Apply grease to a new oil seal, then
install it into the coil assembly.
2
1
S66T5690
Needle bearing attachment 1:
90890-06654
Driver rod L3 2: 90890-06652
2. Install the new O-ring.
1
2
3
4
Disassembling the base assembly
1. Remove the O-ring and oil seal.
5
6
7
8
9
66T5F11
5-18
Page 78
POWR
Power unit
Reed valves
5
No. Part name Q’ty Remarks
1 Intake manifold 1
2 Reed valve assembly 1
3 Clamp 2
4Hose 1
5Bolt 8 M6 × 35 mm
6Hose 1
5-19
66T5F11
Page 79
Removing the reed valve assembly
1. Disconnect the hoses 1.
2. Remove the intake manifold bolts 2, and
then remove the intake manifold and
reed valve assembly.
2
1
1
S66T5280
Checking the reed valve
1. Check the reed valves for bends a.
Replace if above specification.
Reed valves
Valve stopper height b:
10.2–10.4 mm (0.40–0.41 in)
1
2
3
4
Valve bend limit a:
0.2 mm (0.008 in)
2. Measure the valve stopper height b.
Replace if out of specification.
5
6
7
8
9
66T5F11
5-20
Page 80
POWR
Power unit
Cylinder head
5
No. Part name Q’ty Remarks
1Gasket 1
Not reusable
2 Cylinder head 1
3 Thermoswitch 1
4Bolt 11 M8 × 70 mm
5Gasket 1
Not reusable
6 Cover 1
7Bolt 4 M6 × 35 mm
8 Thermostat 1
9 Spark plug 2
10 Cylinder head cover 1
11 Bolt 4 M6 × 25 mm
12 Gasket 1
Not reusable
13 Bolt 9 M6 × 25 mm
14 Exhaust cover 1
15 Gasket 1
Not reusable
16 Pilot water hose 1
5-21
66T5F11
Page 81
Removing the cylinder head
1. Remove the spark plugs, thermostat
cover, and thermostat.
2. Remove the cylinder head cover bolts 1.
3. Remove the cylinder head bolts in the
sequence shown.
Cylinder head
Cylinder head warpage limit:
0.1 mm (0.004 in)
Removing the exhaust cover
1. Remove the exhaust cover bolts in the
sequence shown.
1
2
3
CAUTION:
Do not scratch or damage the mating surfaces of the cylinder head and cylinder
block.
Checking the cylinder head
1. Eliminate carbon deposits from the combustion chambers and check for deterioration or corrosion.
2. Check the cylinder head warpage using a
straightedge 1 and thickness gauge
in four directions as shown. Replace if
above specification.
2
S66T5310
Checking the exhaust cover
1. Check the exhaust cover for distortion or
corrosion. Replace if necessary.
4
5
6
7
8
66T5F11
9
5-22
Page 82
POWR
Power unit
Crankcase
5
No. Part name Q’ty Remarks
1 Crankshaft assembly 1
2 Anode 1
3Screw 1
4 Cylinder block 1
5 Anode 1
6Screw 1 ø6 × 20 mm
7 Oil seal 2
8 Oil seal 2
9O-ring 1
10 Oil seal housing 1
11 Bolt 1 M6 × 20 mm
12 Spacer 1
13 Crankcase 1
14 Bolt 10 M10 × 55 mm
15 Bolt 4 M6 × 30 mm
16 Bracket 1
17 Bracket 1
Not reusable
Not reusable
Not reusable
5-23
66T5F11
Page 83
Crankcase
5
1
2
3
No. Part name Q’ty Remarks
18 Hose 1
19 Dowel 2
20 Bolt 2 M8 × 20 mm
21 Engine hanger 1
4
5
6
7
8
66T5F11
9
5-24
Page 84
POWR
Power unit
5
No. Part name Q’ty Remarks
1Crank 3 1
2 Washer 4
3 Roller bearing 2
4 Connecting rod 2
5 Needle bearing 56
6 Clip 4
Not reusable
7Piston 2
8 Piston pin 2
9 Piston ring assembly 2
10 Crankpin 2
11 Crank 4 1
12 Ball bearing 1
Not reusable
13 Labyrinth ring 1
14 Roller bearing 1
15 Crank 2 1
16 Crank 1 1
17 Ball bearing 1
Not reusable
5-25
66T5F11
Page 85
Crankcase
Removing the crankcase and oil seal
housing
1. Remove the crankcase bolts in the
sequence shown.
S66T5350
2. Remove the bolt 1, then the oil seal
housing 2.
Checking the cylinder bore
1. Measure the cylinder bore (D1–D6) at
measuring points a, b, and c, and in
direction d (D
to the crankshaft, and direction e (D
, D6), which is at a right angle to the
D
4
crankshaft.
a
: 20 mm (0.79 in) from the cylinder block sur-
face
b
: 5 mm (0.20 in) above the exhaust port upper
edge
c
: 5 mm (0.20 in) below the scavenging port
lower edge
, D3, D5), which is parallel
1
,
2
1
2
3
4
2
1
Removing the crankshaft assembly
1. Remove the crankshaft assembly.
S66T5360
Cylinder bore (D1–D6):
80.000–80.020 mm
(3.1496–3.1504 in)
2. Calculate the taper limit. Replace or
rebore the cylinder block if above specification.
Taper limit:
D
D
3. Calculate the out-of-round limit. Replace
or rebore the cylinder block if above
specification.
Out-of-round limit:
D
D
(direction d)
1–D5
(direction e)
2–D6
0.08 mm (0.0031 in)
(measuring point a)
2–D1
(measuring point c)
6–D5
0.05 mm (0.0020 in)
5
6
7
8
9
66T5F11
5-26
Page 86
POWR
Power unit
Disassembling the oil seal housing
1. Remove the O-ring and oil seals.
Checking the oil seal housing
1. Check the oil seal housing for cracks,
damage, or corrosion. Replace if necessary.
Assembling the oil seal housing
1. Apply grease to new oil seals, then install
them into the oil seal housing.
2
Needle bearing attachment
90890-06655
Driver rod LS 4: 90890-06606
3. Install the new O-ring.
3:
Disassembling the piston
1. Remove the clips with pliers, and then
remove the piston pin.
2. Separate the piston from the connecting
rod.
1
S66T5430
Needle bearing attachment 1:
90890-06613
Driver rod L3 2: 90890-06652
2. Apply grease to new oil seals, then install
them into the oil seal housing.
4
3
3. Remove the bearing and washers at the
connecting rod small end.
4. Remove the top ring and 2nd piston ring.
Checking the piston diameter
1. Measure the piston outside diameter at
the specified measuring point. Replace if
out of specification.
5-27
S66T5440
66T5F11
Page 87
Piston diameter:
79.910–79.934 mm
(3.1461–3.1470 in)
Measuring point a:
10 mm (0.39 in) up from the bottom
of the piston skirt
Oversize piston diameter:
1st:
80.160–80.184 mm
(3.1559–3.1568 in)
2nd:
80.410–80.434 mm
(3.1657–3.1667 in)
Crankcase
2. Level the piston rings 1 in a cylinder with
a piston crown.
3. Check the piston ring end gap c at the
specified measuring point. Replace if out
of specification.
d
1
1
1
2
Checking the piston clearance
1. Calculate the piston clearance using the
piston outside diameter and the cylinder
bore specifications. Replace the piston
and piston rings as a set or the cylinder
block or all parts, or rebore the cylinder if
out of specification.
Piston clearance:
0.085–0.090 mm
(0.0033–0.0035 in)
Checking the piston rings
1. Check the piston ring dimensions of B
and T. Replace if out of specification.
a
B
T
b
c
S66T5470
Piston ring end gap c:
Top ring and 2nd piston ring:
0.30–0.50 mm
(0.0118–0.0197 in)
Measuring point d: 20 mm (0.8 in)
Checking the piston ring side
clearance
1. Measure the piston ring side clearance.
Replace the piston and piston rings as a
set if out of specification.
3
4
5
6
7
66T5F11
B
T
Piston ring dimensions:
Top ring a and 2nd piston ring b:
B: 1.97–1.99 mm
(0.0776–0.0783 in)
T: 2.40–2.60 mm
(0.0945–0.1024 in)
S66T5460
Piston ring side clearance:
Top ring:
0.04–0.08 mm
(0.0015–0.0031 in)
2nd piston ring:
0.03–0.07 mm
(0.0012–0.0028 in)
8
S66T5480
9
5-28
Page 88
POWR
Power unit
Checking the piston pin boss bore
1. Measure the piston pin boss bore.
Replace the piston if out of specification.
S60V5870
Piston pin boss bore:
19.904–19.915 mm
(0.7836–0.7841 in)
Checking the piston pin
1. Measure the piston pin diameter.
Replace if out of specification.
Bearing separator: 90890-06534
Piston pin diameter:
19.895–19.900 mm
(0.7833–0.7835 in)
Disassembling the crankshaft
1. Remove the upper and lower bearings.
2. Insert the plate C 1 between crank 1
and crank 2 3. Place pressure pin C
2
4
in the end of the crankpin 5.
2
4
3
1
5
S66T5510
NOTE:
Remove the bearing before starting this procedures.
5-29
Plate C 1: 90890-02402
Pressure pin C 4: 90890-02403
3. Remove the crankpin by applying pressure to pressure pin C 4 using a press.
66T5F11
Page 89
Crankcase
9
CAUTION:
• Apply pressure to pressure pin C
slowly.
• Hold pressure pin C in line with the
press screw spindle.
NOTE:
• When forcing out the crankpin, use care so
that the crank does not fall.
• To remove crank 4, follow the same procedure.
4. Remove the washers, roller bearing and
connecting rod.
5. Insert the support 6 between cranks 2
and 3 7 with crank 3 on top. Place pressure pin B 8 on the shaft, and force it out
using a press.
0
S66T5540
7. Remove the crankpin between cranks 2
and 3 by applying pressure to pressure
pin C using a press.
NOTE:
Pressure pin C should be pressed down
straight.
Plate C 1: 90890-02402
Pressure pin C 4: 90890-02403
1
2
3
4
5
6
Support 6: 90890-02394
Pressure pin B 8: 90890-02390
6. Remove the roller bearing 9 from the
inner race 0.
66T5F11
8. Use the bearing separator to slightly
move the inner race off the shaft, and
then remove the inner race.
S66T5560
NOTE:
Use care not to scratch the shaft.
5-30
7
8
9
Page 90
POWR
Power unit
Checking the crankpin
1. Measure the crankpin diameter. Replace
if out of specification.
Crankpin diameter:
26.995–27.000 mm
(1.0628–1.0630 in)
Assembling the crankshaft
CAUTION:
• When reassembling the crankshaft,
wash all component parts in clean kerosene (do not use gasoline).
• Do not reuse bearings, always replace
them with new ones.
CAUTION:
• Take care so that the crankpin is set
squarely into the crank web.
• Do not apply force in excess of 5 tons.
NOTE:
Follow the same procedure for both crank 2
and crank 4 to install the crankpins using a
press.
3. Insert the bushing 3 into the body 4.
1. Insert spacer C 1 into the crankpin hole
of crank 2 (or crank 4).
Spacer C 1: 90890-02404
Support 2: 90890-02394
2. Apply engine oil to the crankpin and
insert it into the crankpin hole by tapping
it with a copper hammer, and then install
the crankpin using a press.
Bushing-9 (D30) 3: 90890-02363
Body 4: 90890-02352
Flange 5: 90890-02351
5-31
66T5F11
Page 91
Crankcase
4. Place the height ring 6 in the body.
NOTE:
Align the slot in the height ring with the slot in
the body.
Height ring-640 (H19) 6:
90890-06590
5. Set the spacer on the crank 2 (or crank
4).
NOTE:
• Take care so that spacer C 1 does not fall
out of the crank, turn the crank over so that
the crankpin is on top, and then insert the
crank into the special service tool.
• The model number a on the connecting
rod should face up.
8. Install the bushing 7 on the pressure
plate 8.
1
2
3
4
1
1
S66T5910
Spacer C 1: 90890-02404
6. Set crank 2 (or crank 4) on the special
service tool.
7. Mount the washers, roller bearing, and
connecting rod on the crankpin.
1
NOTE:
When installing crank 3 to the pressure plate,
do not use the bushing 7.
Bushing-12 (D35) 7: 90890-02366
Pressure plate 8: 90890-02384
9. Install crank 1 (or crank 3) to the pressure plate.
5
6
7
8
E
66T5F11
9
a
S66T5750
5-32
Page 92
POWR
Power unit
10. Align the crankpin hole in crank 1 (or
crank 3) with the crankpin fitted to crank
2 (or crank 4) and place the pressure
plate in the body.
NOTE:
Apply engine oil to the crankpin.
11. Insert the press body 9, and install
crank 1 (or crank 3) onto the crankpin
using a press.
NOTE:
If any of the measurements are out of specification, reassemble the crankshaft.
Crankshaft width b:
63.90–63.95 mm
(2.5157–2.5177 in)
13. Install the inner race 0 onto crank 2 by
using a press and the bushing 3. Carefully press the inner race onto the shaft.
B
3
0
A
CAUTION:
Do not apply force in excess of 5 tons.
Press body 9: 90890-02385
12. Measure the width b of the assembled
crankshaft using calipers. Measurements
should be made at positions c to g.
5-33
S66T5700
Plate C A: 90890-02402
Bushing-9 (D30) 3: 90890-02363
Bearing pressure C B: 90890-02393
66T5F11
Page 93
14. Install the roller bearing C onto crank 2.
C
Crankcase
h
E
S66T5810
NOTE:
Make sure the pin h side of the bearing
faces crank 2.
15. Insert plate C 0 between crank 1 and
crank 2, and install the labyrinth ring on
crank 3, before connecting crankshaft
assemblies 3 and 4.
16. Insert plate C 0 between crank 3 and
crank 4, then place them onto the crankshaft assemblies 1 and 2.
CAUTION:
Do not apply force in excess of 7 tons.
Press body 9: 90890-02385
Checking the crankshaft
1. Measure the crankshaft widths a and b.
Repair or disassemble the crankshaft if
out of specification.
2. Measure the connecting rod small end
axial play. Replace the bearing and connecting rod if above specification.
1
2
3
4
5
NOTE:
Align the alignment marks i on cranks 2 and
3.
Plate C 0: 90890-02402
17. Place the press body 9 on plate C and
install crank 2 into crank 3 using a press.
Crankshaft width a:
63.90–63.95 mm
(2.5157–2.5177 in)
Crankshaft width b:
40.88–41.10 mm
(1.6094–1.6181 in)
Connecting rod small end axial play
limit:
2.0 mm (0.079 in)
6
7
8
9
66T5F11
5-34
Page 94
POWR
Power unit
3. Measure the crankshaft runout. Repair or
disassemble the crankshaft if above
specification.
Crankshaft runout limit c:
0.03 mm (0.0012 in)
2. Slowly turn the crankshaft and connecting rods. If it does not turn smoothly, disassemble the crankshaft and adjust or
replace any parts as necessary.
Assembling the piston
1. Install the 2nd piston ring 1 and top ring
2
onto the pistons.
Installing the crankshaft bearings
1. Install the upper and lower bearings
using the bearing pressure C 1 and a
press.
NOTE:
• Install the upper bearing so that the manu-
facture identification mark a faces the flywheel magnet side.
• Install the lower bearing so that the dowel
b
faces the flywheel magnet side.
NOTE:
Install the piston rings with the recess for the
locating pin facing up toward the piston
crown.
2. Install the needle bearings 3, washers
4
, piston pin 5, and new clips 6.
5-35
Bearing pressure C 1:
90890-02393
66T5F11
Page 95
Crankcase
1
NOTE:
• Make sure that the piston and piston pin
bearings are installed in their original combination.
• Use the small end bearing installer 7 to
install the needle bearings.
• Make sure that the up mark on the piston
crown faces the flywheel magnet side.
Small end bearing installer 7:
90890-06527
2
NOTE:
• Apply engine oil to the pistons, piston rings
and bearings before installation.
• Align the dowels of the bearings with the
holes 1 on the cylinder block.
• Align the spacer 2 and rings 3 with the
grooves in the cylinder block.
2. Install the oil seal housing 4 and bolt 5,
and then tighten the bolt finger tight.
4
LT
LT
572
3
5
S66T5580
S66T5590
2
3
4
5
6
Assembling the power unit
1. Install the crankshaft assembly into the
cylinder block.
66T5F11
3. Apply sealant to the mating surface of
the crankcase.
GM
S66T5600
NOTE:
Do not get any sealant on the crankshaft
journals.
5-36
7
8
9
Page 96
POWR
T
R
.
.
T
R
.
.
Power unit
4. Install the crankcase onto the cylinder
block, and then tighten the crankcase
bolts to the specified torques in two
stages and in the sequence shown.
S66T5610
NOTE:
Apply engine oil to the crankcase bolts before
installation.
NOTE:
Apply LOCTITE 572 to the exhaust cover
bolts before installation.
Exhaust cover bolt:
1st: 6 N·m (0.6 kgf·m, 4.4 ft·lb)
2nd: 12 N·m (1.2 kgf·m, 8.9 ft·lb)
7. Install a new cylinder head gasket, the
cylinder head, thermoswitch, a new cylinder head cover gasket, and cylinder head
cover, and then tighten the cylinder head
bolts to the specified torques in two
stages and in the sequence shown.
8. Install the cylinder head cover bolts 6,
and then tighten the bolts to the specified
torques in two stages.
Crankcase bolt:
T
.
R
.
1st: 20 N·m (2.0 kgf·m, 14.8 ft·lb)
2nd: 40 N·m (4.0 kgf·m, 29.5 ft·lb)
5. Tighten the oil seal housing bolt.
6. Install a new gasket and the exhaust
cover, and then tighten the bolts to the
specified torques in two stages and in the
sequence shown.
NOTE:
Apply LOCTITE 572 to the cylinder head
bolts and the cylinder head cover bolts before
installation.
Cylinder head bolt:
1st: 15 N·m (1.5 kgf·m, 11.1 ft·lb)
2nd: 30 N·m (3.0 kgf·m, 22.1 ft·lb)
Cylinder head cover bolt 6:
1st: 6 N·m (0.6 kgf·m, 4.4 ft·lb)
2nd: 12 N·m (1.2 kgf·m, 8.9 ft·lb)
S66T5620
9. Install the thermostat, a new gasket and
thermostat cover.
5-37
66T5F11
Page 97
10. Install the spark plugs, tighten them fin-
T
R
.
.
ger tight, then to the specified torque with
a spark plug wrench.
Spark plug:
T
.
R
.
25 N·m (2.5 kgf·m, 18.4 ft·lb)
11. Install the reed valve assembly and the
intake manifold assembly, and then
tighten the intake manifold bolts 7 to the
specified torques in two stages.
12. Connect the hoses 8.
Crankcase
1
2
NOTE:
Apply LOCTITE 572 to the power unit mounting bolts before installation.
7
8
8
S66T5640
Intake manifold bolt 7:
T
.
R
.
1st: 6 N·m (0.6 kgf·m, 4.4 ft·lb)
2nd: 12 N·m (1.2 kgf·m, 8.9 ft·lb)
13. Install the throttle cam assembly, and the
electrical components to the power unit.
Installing the power unit
1. Clean the power unit mating surface, and
install the dowels 1 and a new gasket
2
.
Power unit mounting bolt 4:
21 N·m (2.1 kgf·m, 15.5 ft·lb)
4. Connect the fuel hose and pilot water
hose.
5. Connect the engine stop lanyard switch
leads 6 (MH and WH models).
6. Connect the battery leads and neutral
switch connectors (WH and W models).
7. Install the Woodruff key and flywheel
magnet.
3
4
5
6
7
2. Install the power unit 3, and then tighten
the power unit mounting bolts 4 to the
specified torque.
3. Install the apron 5.
66T5F11
5-38
8
9
Page 98
POWR
Power unit
8. Tighten the flywheel magnet nut to the
specified torque.
CAUTION:
Apply force in the direction of the arrows
shown, to prevent the flywheel holder
from slipping off easily.
NOTE:
Apply engine oil to the flywheel magnet nut
before installation.
13. Install all removed parts.
Flywheel holder: 90890-06522
Flywheel magnet nut:
T
.
R
.
157 N·m (15.7 kgf·m, 115.8 ft·lb)
9. Install the starter pulley.
10. Connect the remote control cables
(remote control model) or the throttle
cables (tiller handle model), and then
adjust their length. For adjustment procedures, see Chapter 3.
11. Install the manual starter 7 and start-in
gear protection cable 8, and then adjust
it length. For adjustment procedures, see
Chapter 3.
12. Connect the engine start button connectors 9 (WH model).
5-39
66T5F11
Page 99
LOWR
Lower unit
Special service tools .....................................................................................6-1
Lower unit.......................................................................................................6-4
Removing the lower unit ............................................................................6-8
Removing the water pump and shift rod.................................................... 6-8
Checking the water pump and shift rod.....................................................6-8
Propeller shaft housing.................................................................................6-9
Removing the propeller shaft housing assembly.....................................6-10
Disassembling the propeller shaft assembly ...........................................6-10
Disassembling the propeller shaft housing.............................................. 6-10
Checking the propeller shaft housing ......................................................6-11
Checking the propeller shaft....................................................................6-11
Assembling the propeller shaft assembly ................................................6-11
Assembling the propeller shaft housing...................................................6-11
Drive shaft and lower case..........................................................................6-13
Removing the drive shaft.........................................................................6-14
Disassembling the drive shaft..................................................................6-14
Disassembling the forward gear ..............................................................6-14
Disassembling the oil seal housing .........................................................6-14
Disassembling the lower case .................................................................6-15
Checking the pinion and forward gear..................................................... 6-15
Checking the bearings.............................................................................6-15
Checking the drive shaft ..........................................................................6-15
Checking the lower case .........................................................................6-15
Assembling the oil seal housing ..............................................................6-16
Assembling the lower case......................................................................6-16
Assembling the forward gear...................................................................6-17
Assembling the drive shaft ......................................................................6-17
Installing the pinion..................................................................................6-17
Installing the oil seal housing...................................................................6-17
Installing the propeller shaft housing.......................................................6-18
Installing the water pump and shift rod....................................................6-18
Installing the lower unit ............................................................................6-19
1
2
3
4
5
6
7
66T5F11
Shimming......................................................................................................6-22
Shimming.................................................................................................6-23
Selecting the pinion shims.......................................................................6-23
Selecting the forward gear shims ............................................................6-24
Selecting the reverse gear shims ............................................................6-25
Backlash .......................................................................................................6-26
Measuring the forward and reverse gear backlash .................................6-26
8
9
Page 100
LOWR
Lower unit
Special service tools
Stopper guide plate
90890-06501
Bearing separator
90890-06534
6
Driver rod L3
90890-06652
Ball bearing attachment
90890-06637
Stopper guide stand
90890-06538
Bearing puller assembly
90890-06535
Needle bearing attachment
90890-06608, 90890-06614
Driver rod LS
90890-06606
Bearing inner race attachment
90890-06639, 90890-06641, 90890-06644
Drive shaft holder 3
90890-06517
6-1
66T5F11
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