Yamaha F90D Service Manual
F90D
SERVICE MANUAL
6D8-28197-1G-11LIT-18616-02-86
*LIT186160286*
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
1
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.
F90D
SERVICE MANUAL
©2004 by Yamaha Motor Corporation, USA
1st Edition, June 2004
All rights reserved.
Any reprinting or unauthorized use
without the written permission of
Yamaha Motor Corporation, USA
is expressly prohibited.
Printed in USA
LIT-18616-02-86
Contents
General information
1
GEN
INFO
Specifications
2
SPEC
Periodic checks and adjustments
3
CHK
ADJ
Fuel system
4
FUEL
Power unit
5
POWR
Lower unit
6
LOWR
Bracket unit
7
BRKT
Electrical systems
8
ELEC
Troubleshooting
9
TRBL
SHTG
Index
–+
6D81G11
GEN
INFO
1
2
3
4
5
6
7
8
9
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
Identification...................................................................................................1-5
Applicable model .......................................................................................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 engine oil level.....................................................................1-6
Checking the gear oil level ........................................................................1-7
Checking the battery..................................................................................1-7
Checking the outboard motor mounting height..........................................1-7
Checking the remote control cables ..........................................................1-7
Checking the steering system ...................................................................1-8
Checking the gear shift and throttle operation...........................................1-8
Checking the power trim and tilt system....................................................1-8
Checking the engine start switch and engine stop lanyard switch ............1-8
Checking the cooling water pilot hole ........................................................1-9
Test run .....................................................................................................1-9
Break-in .....................................................................................................1-9
After test run ..............................................................................................1-9
GEN
INFO
General information
1-1
6D81G11
How to use this manual
1
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.”
LOWR
Lower unit
6-5
62Y5A11
Lower unit
No. Part name Q’ty Remarks
1 Lower unit 1
2 Plastic tie 1
Not reusable
3Hose 1
4 Check screw 1
5 Gasket 2
Not reusable
6 Dowel pin 2
7 Bolt 4 M10
40 mm
8 Drain screw 1
9Grommet 1
10 Bolt 1 M
10 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
Not reusable
17 Propeller nut 1
18 Trim tab 1
LOWR
Lower unit
6-19
62Y5A11
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
a
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.
CAUTION:
Do not reuse the bearing, always replace
it with a new one.
2. Remove the needle bearing from the forward gear.
CAUTION:
Do not reuse the bearing, always replace
it with a new one.
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
S62Y6850K
Bearing separator 1: 90890-06534
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
5
4
3
2
1
6D81G11
1-2
1
2
3
4
5
6
7
8
9
Symbols
The symbols below are designed to indicate the content of a chapter.
General information
Specifications
Periodic checks and adjustments
Fuel system
Power unit
Lower unit
Bracket unit
Electrical systems
Troubleshooting
GEN
INFO
SPEC
CHK
ADJ
FUEL
POWR
LOWR
BRKT
ELEC
TRBL
SHTG
– +
Symbols 1 to 6 indicate specific data.
1
Special tool
2
Specified oil or fluid
3
Specified engine speed
4
Specified tightening torque
5
Specified measurement
6
Specified electrical value
(resistance, voltage, electric current)
Symbols 7 to C in an exploded diagram indicate the grade of lubricant and the lubrication point.
7
Apply Yamaha 4-stroke motor oil
8
Apply gear oil
9
Apply water resistant grease (Yamaha grease A)
0
Apply molybdenum disulfide grease
A
Apply corrosion resistant grease
(Yamaha grease D)
B
Apply low temperature resistant grease
(Yamaha grease C)
C
Apply injector grease
Symbols D to H in an exploded diagram indicate the type of sealant or locking agent and the application point.
D
Apply Gasket Maker
E
Apply LOCTITE 271 (red)
F
Apply LOCTITE 242 (blue)
G
Apply LOCTITE 572
H
Apply silicon sealant
123456
T
R
.
.
7890ABC
E G
A M
D
C I
DEFGH
GM
271
LT
242
LT
572
LT
SS
How to use this manual
GEN
INFO
General information
1-3
6D81G11
Safety while working
1
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.
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.
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.
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.
6D81G11
1-4
1
2
3
4
5
6
7
8
9
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.
Safety while working
GEN
INFO
General information
1-5
6D81G11
Identification
1
Applicable model
This manual covers the following model.
Serial number
The outboard motor serial number is
stamped on a label attached to the port
clamp bracket.
1
Model name
2
Approved model code
3
Transom height
4
Serial number
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 the
propeller boss end, on the side of the propeller boss.
a
Propeller diameter (in inches)
b
Propeller pitch (in inches)
c
Propeller type (propeller mark)
Applicable model
F90TR
Model name
Approved
model code
Starting
serial No.
F90TR 61P 1007790–
S6D81010
S69J1100
× -
abc
S60C1120
× -
abc
6D81G11
1-6
1
2
3
4
5
6
7
8
9
Selection
When the engine speed is at the full throttle
operating range (5,000–6,000 r/min), the
ideal propeller for the boat is one that provides maximum performance in relation to
boat speed and fuel consumption.
Predelivery checks
1
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.
CAUTION:
This is a 4-stroke engine. Never use premixed fuel.
Checking the engine oil level
1. Check the engine oil level.
NOTE:
If the engine oil is below the minimum level
mark b, add sufficient oil until the level is
between a and b.
Propeller size (in) Material
12 5/8 × 21 - K
Aluminum
13 × 19 - K
13 × 23 - K
13 × 25 - K
13 1/4 × 17 - K
13 1/2 × 15 - K
13 5/8 × 13 - K
14 × 11 - K
13 × 17 - K
Stainless
13 × 19 - K
13 × 21 - K
13 × 23 - K
13 × 25 - K
13 1/2 × 14 - K
13 1/2 × 16 - K
Recommended engine oil:
4-stroke motor oil
API: SE, SF, SG, SH, or SJ
SAE: 10W-30 or 10W-40
Engine oil quantity:
Without oil filter replacement:
4.3 L (4.55 US qt, 3.78 Imp qt)
S6D81020
S60C1150
a
b
Identification / Propeller selection / Predelivery checks
GEN
INFO
General information
1-7
6D81G11
Checking the gear oil level
1. Check the gear oil level.
Checking the battery
1. Check the capacity, electrolyte level, and
specified gravity of the battery.
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
aligned with the bottom of the boat. 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.
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 bolts.
Checking the remote control cables
1. Set the remote control lever to the neutral position and fully close the throttle
lever.
2. Check that the stopper 1 on the throttle
cam contacts the fully closed stopper
2
on the cylinder block.
3. Check that the alignment mark a on the
bushing is aligned with the alignment
mark b on the bracket.
Recommended battery capacity:
CCA/SAE: 380 A
MCA/ABYC: 502 A
RC/SAE: 124 Minute
Electrolyte specified gravity:
1.280 at 20 °C (68 °F)
S60C1140
S6D81030
2
1
S6D81040
a
b
6D81G11
1-8
1
2
3
4
5
6
7
8
9
WARNING
The shift/throttle cable joint must be
screwed in a minimum of 8.0 mm (0.31 in)
c
.
Checking the steering system
1. Check the steering friction for proper
adjustment.
2. Check that the steering operates
smoothly.
3. Check that there is no interference with
wires or hoses when the outboard motor
is steered.
Checking the gear shift and throttle
operation
1. Check that the gear shift operates
smoothly when the remote control lever
is shifted from neutral to forward or
reverse.
2. Check that the throttle operates smoothly
when the remote control lever is shifted
from forward or reverse to the fully open
position a.
Checking the power trim and tilt
system
1. Check that the outboard motor tilts up
and down smoothly when operating the
power trim and tilt unit.
2. Check that there is no abnormal noise
produced when the outboard motor is
tilted up or down.
3. Check that there is no interference with
wires or hoses when the tilted-up outboard motor is steered.
4. Check that the trim meter points down
when the outboard motor is tilted all the
way down.
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.
S69J3370
c
S60C1200
S69J1210
F
N
R
a
a
S60V1070
Predelivery checks
GEN
INFO
General information
1-9
6D81G11
3. Check that the engine turns off when the
engine stop lanyard is pulled from the
engine stop lanyard switch.
Checking the cooling water pilot
hole
1. Check that cooling water is discharged
from the cooling water pilot hole.
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
2,000 r/min or at half throttle, then for
another hour at 3,000 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.
Break-in
During the test run, perform the break-in
operation in the following three stages.
1. One hour a at 2,000 r/min or at approximately half throttle
2. One hour b at 3,000 r/min or 3/4 throttle
and 1 minute out of every 10 at full throttle
3. Eight hours c at any speed, however,
avoid running at full speed for more than
5 minutes
È
Hour
After test run
1. Check for water in the gear oil.
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.
S69J1240
0
1
210
È
ab
c
6D81G11
SPEC
1
2
3
4
5
6
7
8
9
Specifications
General specifications...................................................................................2-1
Maintenance specification ............................................................................2-3
Power unit..................................................................................................2-3
Lower unit ..................................................................................................2-6
Electrical ....................................................................................................2-6
Dimensions................................................................................................2-9
Tightening torques.......................................................................................2-11
Specified torques.....................................................................................2-11
General torques.......................................................................................2-13
SPEC
Specifications
2-1
6D81G11
General specifications
2
Item Unit
Model
F90TR
Dimension
Overall length mm (in) 817 (32.2)
Overall width mm (in) 479 (18.9)
Overall height
(L) mm (in) 1,582 (62.3)
(X) mm (in) 1,710 (67.3)
Boat transom height
(L) mm (in) 508 (20.0)
(X) mm (in) 635 (25.0)
Weight
(without propeller)
(L) kg (lb) 168 (370)
(X) kg (lb) 172 (379)
Performance
Maximum output kW (hp) 66.2 (90) at 5,500 r/min
Full throttle operating range r/min 5,000–6,000
Maximum fuel consumption L (US gal,
Imp gal)/hr
33.0 (8.72, 7.26) at 6,000 r/min
Engine idle speed r/min 700 ± 50
Power unit
Type In-line, 4-stroke, DOHC, 16 valves
Cylinder quantity 4
Total displacement cm
3
(cu. in) 1,596 (97.39)
Bore × stroke mm (in) 79.0 × 81.4 (3.11 × 3.20)
Compression ratio 9.6
Control system Remote control
Starting system Electric
Fuel system Fuel injection
Ignition control system TCI
Advance type Micro computer
Maximum generator output V, A 12, 25
Spark plug LFR5A-11 (NGK)
Cooling system Water
Exhaust system Propeller boss
Lubrication system Wet sump
6D81G11
2-2
1
2
3
4
5
6
7
8
9
(*1)
RON: Research Octane Number
PON: Pump Octane Number =
(RON + Motor Octane Number)/2
(*2)
CCA: Cold Cranking Ampere
MCA: Marine Cranking Ampere
ABYC: American Boat and Yacht Council
SAE: Society of Automotive Engineers
RC: Reserve Capacity
Fuel and oil
Fuel type Regular unleaded gasoline
Fuel minimum rating RON
(*1)
PON
91
86
Engine oil 4-stroke motor oil
Engine oil grade API
SAE
SE, SF, SG, SH, or SJ
10W-30 or 10W-40
Engine oil quantity
(without oil filter replacement) L (US qt,
Imp qt)
4.3 (4.55, 3.78)
(with oil filter replacement) L (US qt,
Imp qt)
4.5 (4.76, 3.96)
Gear oil type GEAR CASE LUBE
Gear oil grade SAE 90
Gear oil quantity cm
3
(US oz,
Imp oz)
670 (22.7, 23.6)
Bracket unit
Trim angle
(at 12° boat transom)
Degree –4 to 16
Tilt-up angle Degree 70
Steering angle Degree 35 + 35
Drive unit
Gear shift positions F-N-R
Gear ratio 2.31 (30/13)
Reduction gear type Spiral bevel gear
Clutch type Dog clutch
Propeller shaft type Spline
Propeller direction (rear view) Clockwise
Propeller mark K
Electrical
Battery minimum capacity
(*2)
CCA/SAE A 380
MCA/ABYC A 502
RC/SAE Minute 124
Item Unit
Model
F90TR
General specifications
SPEC
Specifications
2-3
6D81G11
Maintenance specification
2
Power unit
Item Unit
Model
F90TR
Power unit
Minimum compression
pressure
(*1)
kPa
(kgf/cm2, psi)
860 (8.6, 124.7)
Oil pressure
(*2)
kPa
(kgf/cm
2
, psi)
510 (5.1, 74.0) at engine idle speed
Cylinder head
Warpage limit mm (in) 0.1 (0.0039)
(lines indicate straightedge
position)
Camshaft cap inside diameter mm (in) 25.000–25.021 (0.9843–0.9851)
Cylinders
Bore size mm (in) 79.000–79.020 (3.1102–3.1110)
Taper limit mm (in) 0.08 (0.0032)
Out-of-round limit mm (in) 0.05 (0.0020)
Pistons
Piston diameter (D) mm (in) 78.928–78.949 (3.1074–3.1082)
Measuring point (H) mm (in) 13.0 (0.51)
Piston clearance mm (in) 0.070–0.080 (0.0028–0.0031)
Over size piston diameter mm (in) 79.178–79.199 (3.1172–3.1181)
Piston rings
Top ring
Dimension B mm (in) 1.17–1.19 (0.0461–0.0469)
Dimension T mm (in) 2.80–3.00 (0.1102–0.1181)
End gap mm (in) 0.15–0.30 (0.0059–0.0118)
Side clearance mm (in) 0.04–0.08 (0.0016–0.0031)
2nd piston ring
Dimension B mm (in) 1.47–1.49 (0.0579–0.0587)
Dimension T mm (in) 3.00–3.20 (0.1181–0.1260)
End gap mm (in) 0.70–0.90 (0.0276–0.0354)
Side clearance mm (in) 0.03–0.07 (0.0012–0.0028)
(*1)
Measuring conditions:
Ambient temperature 20 °C (68 °F), wide open throttle, with spark plugs removed from all cylinders.
The figures are for reference only.
(*2)
The figures are for reference only.
6D81G11
2-4
1
2
3
4
5
6
7
8
9
Oil ring
Dimension B mm (in) 2.38–2.48 (0.0937–0.0976)
Dimension T
(*)
mm (in) 2.40 (0.0945)
End gap mm (in) 0.20–0.70 (0.0079–0.0276)
Side clearance mm (in) 0.03–0.15 (0.0012–0.0059)
Camshafts
Intake (A) mm (in) 36.48–36.58 (1.4362–1.4402)
Exhaust (A) mm (in) 36.90–37.06 (1.4528–1.4591)
Intake (B) mm (in) 29.95–30.05 (1.1791–1.1831)
Exhaust (B) mm (in) 29.92–30.08 (1.1780–1.1842)
Camshaft journal diameter mm (in) 24.960–24.980 (0.9827–0.9835)
Camshaft runout limit mm (in) 0.03 (0.0012)
Valves
Valve clearance (cold)
Intake mm (in) 0.20 ± 0.03 (0.008 ± 0.001)
Exhaust mm (in) 0.34 ± 0.03 (0.013 ± 0.001)
Head diameter (A)
Intake mm (in) 29.0–29.2 (1.14–1.15)
Exhaust mm (in) 24.0–24.2 (0.94–0.95)
Face width (B)
Intake mm (in) 1.99–2.44 (0.0783–0.0961)
Exhaust mm (in) 2.27–2.72 (0.0894–0.1071)
Seat contact width (C)
Intake mm (in) 1.20–1.60 (0.0472–0.0630)
Exhaust mm (in) 1.20–1.60 (0.0472–0.0630)
Margin thickness (D)
Intake mm (in) 0.80–1.20 (0.0315–0.0472)
Exhaust mm (in) 1.00–1.40 (0.0394–0.0551)
Stem diameter
Intake mm (in) 5.975–5.990 (0.2352–0.2358)
Exhaust mm (in) 5.960–5.975 (0.2346–0.2352)
Guide inside diameter
Intake and exhaust mm (in) 6.000–6.018 (0.2362–0.2369)
Stem-to-guide clearance
Intake mm (in) 0.010–0.043 (0.0004–0.0017)
Exhaust mm (in) 0.025–0.058 (0.0010–0.0023)
Stem runout limit mm (in) 0.01 (0.0004)
Valve springs
Free length mm (in) 53.20 (2.0945)
Tilt limit mm (in) 2.6 (0.10)
(*)
The figure is for reference only.
Item Unit
Model
F90TR
Maintenance specification
SPEC
Specifications
2-5
6D81G11
Valve lifters
Valve lifter outside diameter mm (in) 27.965–27.980 (1.1010–1.1016)
Valve lifter-to-cylinder head
clearance
mm (in) 0.020–0.056 (0.0008–0.0022)
Valve shims
Valve shim thickness
(in 0.025 mm increments)
mm (in) 2.0–3.3 (0.08–0.13)
Connecting rods
Big end inside diameter mm (in) 47.025–47.045 (1.8514–1.8522)
Big end side clearance mm (in) 0.14–0.28 (0.0055–0.0110)
Crankpin oil clearance mm (in) 0.024–0.044 (0.0009–0.0017)
Big-end bearing thickness
Yellow mm (in) 1.499–1.506 (0.0590–0.0593)
Green mm (in) 1.506–1.513 (0.0593–0.0596)
Blue mm (in) 1.513–1.520 (0.0596–0.0598)
Red mm (in) 1.520–1.527 (0.0598–0.0601)
Crankshaft
Crankshaft journal diameter mm (in) 47.985–48.000 (1.8892–1.8898)
Crankpin diameter mm (in) 43.982–44.000 (1.7316–1.7323)
Crankpin width mm (in) 21.00–21.07 (0.8268–0.8295)
Runout limit mm (in) 0.03 (0.0012)
Crankcase
Crankshaft journal oil
clearance
mm (in) 0.024–0.044 (0.0009–0.0017)
Upper crankcase main bearing
thickness
Green mm (in) 2.992–2.999 (0.1178–0.1181)
Blue mm (in) 2.999–3.006 (0.1181–0.1183)
Red mm (in) 3.006–3.013 (0.1183–0.1186)
Upper crankcase main bearing
#3 thickness
Green mm (in) 2.992–2.999 (0.1178–0.1181)
Blue mm (in) 2.999–3.006 (0.1181–0.1183)
Red mm (in) 3.006–3.013 (0.1183–0.1186)
Lower crankcase main bearing
thickness
Yellow mm (in) 3.010–3.017 (0.1185–0.1188)
Green mm (in) 3.017–3.024 (0.1188–0.1191)
Blue mm (in) 3.024–3.031 (0.1191–0.1193)
Red mm (in) 3.031–3.038 (0.1193–0.1196)
Item Unit
Model
F90TR
6D81G11
2-6
1
2
3
4
5
6
7
8
9
Lower unit
Electrical
Oil pump
Discharge
at 97–103 °C (207–217 °F)
with 10W-30 engine oil
L (US gal,
Imp gal)/min
5.9 (1.559, 1.298) at 1,000 r/min
Pressure
at 97–103 °C (207–217 °F)
with 10W-30 engine oil
kPa
(kgf/cm
2
, psi)
118.0 (1.18, 17.1) at 1,000 r/min
Relief valve opening pressure kPa
(kgf/cm
2
, psi)
441–539 (4.41–5.39, 63.9–78.2)
Thermostat
Opening temperature °C (°F) 58–62 (136–144)
Fully open temperature °C (°F) 70 (158)
Valve open lower limit mm (in) 4.3 (0.17)
Item Unit
Model
F90TR
Gear backlash
Pinion-to-forward gear mm (in) 0.28–0.63 (0.0110–0.0248)
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
Item Unit
Model
F90TR
Ignition and ignition control
system
Spark plug gap mm (in) 1.0–1.1 (0.039–0.043)
Ignition coil resistance
at 20 °C (68 °F)
Primary coil (R – B/W)
Ω
1.53–2.07
Secondary coil kΩ 12.495–16.905
Spark plug wire resistance
#1 kΩ 4.5–10.7
#2 kΩ 3.3–8.0
#3 kΩ 3.7–8.9
#4 kΩ 4.3–10.2
Item Unit
Model
F90TR
Maintenance specification
SPEC
Specifications
2-7
6D81G11
ECM output peak voltage
(B/R, B/W – Ground)
at cranking (loaded) V 210
at 1,500 r/min (loaded) V 290
at 3,500 r/min (loaded) V 290
Pulser coil output peak voltage
(W/R, W/B – B)
at cranking (unloaded) V 3.6
at cranking (loaded) V 3.4
at 1,500 r/min (loaded) V 18.2
at 3,500 r/min (loaded) V 34.3
Pulser coil resistance
(*)
(W/R, W/B – B)
Ω
459–561
Throttle position sensor
Output voltage (P – B) V 0.8–1.2 at engine idle speed
Cooling water temperature
sensor resistance
at 0 °C (32 °F) kΩ 5.21–6.37
at 80 °C (176 °F) kΩ 0.290–0.354
Oil pressure switch
Operating pressure kPa
(kgf/cm
2
, psi)
127.5–166.7 (1.28–1.67, 18.49–24.17)
Fuel control system
Fuel injector resistance
(*)
at 21 °C (70 °F)
Ω
12.0
Starter motor
Type Sliding gear
Output kW 1.40
Cranking time limit Second 30
Brushes
Standard length mm (in) 15.5 (0.61)
Wear limit mm (in) 9.5 (0.37)
Commutator
Standard diameter mm (in) 29.0 (1.14)
Wear limit mm (in) 28.0 (1.10)
Mica
Standard undercut mm (in) 0.8 (0.03)
Wear limit mm (in) 0.2 (0.01)
(*)
The figures are for reference only.
Item Unit
Model
F90TR
6D81G11
2-8
1
2
3
4
5
6
7
8
9
Charging system
Fuse A 20
Stator coil output peak voltage
(W – W)
at cranking (unloaded) V 12.4
at 1,500 r/min (unloaded) V 45.3
at 3,500 r/min (unloaded) V 98.3
Stator coil resistance
(*)
(W – W)
at 20 °C (68 °F)
Ω
0.24–0.36
Rectifier Regulator output
peak voltage (R–Ground)
at 1,500 r/min (unloaded) V 13.0
at 3,500 r/min (unloaded) V 13.0
Power trim and tilt system
Trim sensor
Setting resistance (P – B)
Ω
10
±
1
Resistance (P – B)
Ω
9–378.8
Fluid type ATF Dexron II
Brushes
Standard length mm (in) 10.0 (0.39)
Wear limit mm (in) 3.5 (0.14)
Commutator
Standard diameter mm (in) 22.0 (0.87)
Wear limit mm (in) 21.0 (0.83)
Mica
Standard undercut mm (in) 1.5 (0.06)
Wear limit mm (in) 1.0 (0.04)
(*)
The figure is for reference only.
Item Unit
Model
F90TR
Maintenance specification
SPEC
Specifications
2-9
6D81G11
Dimensions
Exterior
527 (20.7)
366 (14.4)
49 (1.9)
27 (1.1)
L: 766 (30.2)
X: 842 (33.1)
857 (33.7)
666 (26.2)
L: 917 (36.1)
X: 1,044 (41.1)
L : 536 (21.1)
X: 663 (26.1)
L : 25 (1.0)
X: 24 (0.9)
191 (7.5)
171 (6.73)
62 (2.4)
66˚
574 (22.6)28 (1.1)
164 (6.5)
651 (25.6)
204 (9.4)
405 (15.9)
35˚
L: 998 (39.3)
X: 1,115 (43.9)
63 (2.5)
12˚
4˚
S6D82010
mm (in)
6D81G11
2-10
1
2
3
4
5
6
7
8
9
Clamp bracket
348.5 (13.7)
180 (7.1)
163.5 (6.4)163.5 (6.4)
180 (7.1)
18.5 (0.7)
254 (10.0)
13 (0.5)
80 (3.1)
50.8 (2.0)
55.5 (2.2)
13 (0.5)
125.4 (4.9)125.4 (4.9)
mm (in)
S6D82020
Maintenance specification
SPEC
Specifications
2-11
6D81G11
Tightening torques
2
Specified torques
Part to be tightened Thread size
Tightening torques
N·mkgf·mft·lb
Fuel system
Fuel filter cup — 30.32.2
Fuel pump mounting bolt M6 10 1.0 7.4
Fuel pump screw M6 4 0.4 3.0
Sensor assembly screw M5 3.7 0.37 2.7
Idle speed control screw M5 3.7 0.37 2.7
Fuel rail mounting bolt M6 8 0.8 5.9
Throttle body mounting bolt M6 8 0.8 5.9
Fuel cooler screw M6 3 0.3 2.2
Float chamber screw M5 3 0.3 2.2
Vapor separator drain screw — 1.5 0.15 1.1
Pressure regulator bolt M6 5 0.5 3.7
Fuel hose joint — 40.43.0
Plate screw M4 2 0.2 1.5
Wiring harness holder screw M4 2 0.2 1.5
Pressure check valve — 10 1.0 7.4
Power unit
Power unit mounting bolt
1st
M10
42 4.2 31.0
2nd 42 4.2 31.0
Apron screw M6 4 0.4 3.0
Flywheel magnet nut M24 215 21.5 158.6
Starter motor bolt M8 29 2.9 21.4
Spark plug wire cover screw M6 4 0.4 3.0
Starter relay lead bolt M6 4 0.4 3.0
Starter relay holder screw M6 3 0.3 2.2
Main and fuel pump relay screw M6 3 0.3 2.2
Oil pressure switch — 80.85.9
Oil pressure switch lead bolt M4 2 0.2 1.5
PTT relay lead nut M6 4 0.4 3.0
PTT motor lead bolt M6 4 0.4 3.0
Positive battery lead nut M8 9 0.9 6.6
Timing belt tensioner bolt M10 39 3.9 28.8
Drive sprocket nut M40 265 26.5 195.5
Driven sprocket bolt M10 60 6.0 44.3
Camshaft cap bolt
1st
M7
80.85.9
2nd 17 1.7 12.5
Cylinder head cover plate screw M4 2 0.2 1.5
Cylinder head cover bolt
1st
M6
80.85.9
2nd 8 0.8 5.9
6D81G11
2-12
1
2
3
4
5
6
7
8
9
Cylinder head bolt
1st
M8
14 1.4 10.3
2nd 28 2.8 20.7
1st
M10
15 1.5 11.1
2nd 30 3.0 22.1
3rd 90°
Spark plug — 25 2.5 18.4
Cylinder block plug M14 23 2.3 17.0
Oil filter joint — 49 4.9 36.1
Oil filter — 18 1.8 13.3
Exhaust cover bolt
1st
M6
60.64.4
2nd 12 1.2 8.9
Anode screw M4 2 0.2 1.5
Exhaust cover plug M18 55 5.5 40.6
Crankcase bolt
1st
M8
14 1.4 10.3
2nd 28 2.8 20.7
1st
M10
19 1.9 14.0
2nd 60°
Connecting rod cap bolt
1st
M8
18 1.8 13.3
2nd 80°
Lower unit
Gear oil drain screw — 90.96.6
Gear oil check screw — 90.96.6
Lower case mounting bolt (L-transom model) M10 39 3.9 28.8
Lower case mounting nut (X-transom model) — 39 3.9 28.8
Propeller nut M16 34 3.4 25.1
Ring nut — 103 10.3 76.0
Cooling water inlet cover screw — 50.53.7
Pinion nut M16 93 9.3 68.6
Bracket unit
Shift rod detent bolt — 18 1.8 13.3
Shift position switch screw M4 1 0.1 0.7
Flushing hose adapter screw M6 2 0.2 1.5
Oil pump bolt M6 10 1.0 7.4
Upper mounting nut — 51 5.1 37.6
Lower mounting nut — 51 5.1 37.6
Grease nipple — 30.32.2
Oil pump cover screw M6 4 0.4 3.0
Oil seal housing screw M6 4 0.4 3.0
Upper mount bolt M8 28 2.8 20.7
Muffler assembly bolt M8 20 2.0 14.8
Engine oil drain bolt M14 27 2.7 20.0
Oil strainer bolt M6 10 1.0 7.4
Oil pan bolt M6 11 1.1 8.1
Exhaust manifold bolt M6 11 1.1 8.1
Part to be tightened Thread size
Tightening torques
N·mkgf·mft·lb
Tightening torques
SPEC
Specifications
2-13
6D81G11
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.
Steering arm stud bolt M10 20 2.0 14.8
Self-locking nut — 15 1.5 11.1
Trim sensor cam screw M6 2 0.2 1.5
Power trim and tilt unit
Reservoir cap — 70.75.2
PTT motor bolt M6 4 0.4 3.0
Gear pump bolt M5 5 0.5 3.7
Gear pump housing bolt M5 5 0.5 3.7
Relief valve cap bolt
M4 4 0.4 3.0
M5 5 0.5 3.7
Lever bolt M3 2 0.2 1.5
Manual valve — 20.21.5
Gear pump bracket bolt
M3 2 0.2 1.5
M5 4 0.4 3.0
Trim cylinder end screw — 90 9.0 66.4
Tilt cylinder end screw — 80 8.0 59.0
Tilt piston bolt M12 85 8.5 62.7
Part to be tightened Thread size
Tightening torques
N·mkgf·mft·lb
Nut (A) Bolt (B)
General torque
specifications
N·mkgf·mft·lb
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
6D81G11
CHK
ADJ
1
2
3
4
5
6
7
8
9
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-fuel injector) ..............3-3
Checking the fuel filter ...............................................................................3-3
Power unit.......................................................................................................3-4
Checking the engine oil .............................................................................3-4
Changing the engine oil using an oil changer............................................3-4
Changing the engine oil by draining it .......................................................3-4
Replacing the oil filter ................................................................................3-5
Checking the timing belt ............................................................................3-6
Checking the spark plugs ..........................................................................3-6
Checking the thermostat............................................................................3-7
Checking the cooling water passage.........................................................3-8
Control system...............................................................................................3-8
Checking the engine idle speed ................................................................3-8
Adjusting the throttle link and throttle cable...............................................3-8
Checking the gear shift operation............................................................3-10
Bracket unit ..................................................................................................3-11
Checking the power trim and tilt operation .............................................. 3-11
Checking the power trim and tilt fluid level .............................................. 3-11
Lower unit.....................................................................................................3-12
Checking the gear oil level ......................................................................3-12
Changing the gear oil ..............................................................................3-12
Checking the lower unit for air leakage ...................................................3-13
Checking the propeller.............................................................................3-13
General..........................................................................................................3-14
Checking the anodes...............................................................................3-14
Checking the battery................................................................................3-14
Lubricating the outboard motor................................................................3-15
CHK
ADJ
Periodic checks and adjustments
3-1
6D81G11
Special service tools
3
Digital tachometer
YU-39951-B
Battery powered timing light
YM-33277-A
Pressure/vacuum tester
YB-35956-A
Oil filter wrench
YU-38411
6D81G11
3-2
1
2
3
4
5
6
7
8
9
Maintenance interval chart
3
Use the following chart as a guideline for general maintenance.
Adjust the maintenance intervals according to the operating conditions of the outboard motor.
NOTE:
When operating in salt water, turbid or muddy water, the engine should be flushed with clean water
after each use.
NOTE:
When using lead or high-sulfur gasoline, checking valve clearance may be required more frequently
than every 500 hours.
Item Remarks
Initial Every
Refer to
page
10 hours
(1 month)
50 hours
(3 months)
100 hours
(6 months)
200 hours
(1 year)
Anodes (external) Check/replace 3-14
Anodes (internal) Check/replace 3-14
Battery Check/charge 3-14
Cooling water passages Clean 3-8
Top cowling Check 3-3
Fuel filter
(can be disassembled)
Check/replace 3-3
Fuel system Check 3-3
Gear oil Change 3-12
Lubrication points Lubricate 3-15
Engine idle speed
(EFI models)
Check/adjust 3-8
PCV (Pressure Control Valve) Check 5-38
Power trim and tilt unit Check 3-11
Propeller and cotter pin Check/replace 3-13
Shift link/shift cable Check/adjust 3-10
Thermostat Check 3-7
Throttle link/throttle cable/
throttle pick-up timing
Check/adjust 3-8
Water pump Check 6-9
Engine oil Check/change 3-4
Oil filter Change 3-5
Spark plugs Clean/adjust/
replace
3-6
Timing belt Check/replace 3-6
Item Remarks
Every
Refer to
page
500 hours
(2.5 years)
1,000 hours
(5 years)
Timing belt Replace 5-13
Valve clearance (DOHC) Check/adjust 5-10
Special service tools / Maintenance interval chart
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