Yamaha F90HP User Manual

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F90D

SERVICE MANUAL

*LIT186160286*

6D8-28197-1G-11LIT-18616-02-86

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.

F90D

SERVICE MANUAL

1st Edition, June 2004

Any reprinting or unauthorized use

without the written permission of

Yamaha Motor Corporation, USA

is expressly prohibited.

Printed in USA

LIT-18616-02-86

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

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 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

3 4 5 6 7

6D81G11

8 9

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.

Parts are shown and detailed in an exploded diagram and are listed in the components list.

Tightening torque specifications are provided in the exploded diagrams and after a numbered step with tightening instructions.

Symbols are used to indicate important aspects of a procedure, such as the grade of lubricant and lubrication point.

The components list consists of part names and part quantities, as well as bolt and screw dimensions.

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.”

40 mm

10 45 mm

60 mm

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

8 Drain screw 1

9Grommet 1

10 Bolt 1 M

11 Bolt 1 M8

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

62Y5A11

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.

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

6-19

62Y5A11

6D81G11

Symbols

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

Specified oil or fluid

Specified engine speed

Specified tightening torque

Symbols 7 to C in an exploded diagram indicate the grade of lubricant and the lubrication point.

7890ABC

A M

E G

Apply Yamaha 4-stroke motor oil

Apply gear oil

Apply water resistant grease (Yamaha grease A)

Apply molybdenum disulfide grease

Symbols D to H in an exploded diagram indicate the type of sealant or locking agent and the application point.

DEFGH

271

Specified measurement

Specified electrical value

(resistance, voltage, electric current)

C I

Apply corrosion resistant grease

(Yamaha grease D) Apply low temperature resistant grease

(Yamaha grease C) Apply injector grease

242

572

5 6 7 8 9

Apply Gasket Maker

Apply LOCTITE 271 (red)

Apply LOCTITE 242 (blue)

6D81G11

Apply LOCTITE 572

Apply silicon sealant

1-2

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.

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.

6D81G11

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

6D81G11

1-4

GEN

INFO

General information

Identification

Applicable model

This manual covers the following model.

Applicable model

F90TR

Serial number

The outboard motor serial number is stamped on a label attached to the port clamp bracket.

S6D81010

Propeller selection

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.

Model name

Approved model code

Transom height

Serial number

Model name

Approved

model code

F90TR 61P 1007790–

Starting

serial No.

× -

abc

Propeller diameter (in inches)

Propeller pitch (in inches)

Propeller type (propeller mark)

× -

abc

S69J1100

S60C1120

1-5

6D81G11

Identification / Propeller selection / Predelivery checks

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.

Propeller size (in) Material

12 5/8 × 21 - K

13 × 19 - K

13 × 23 - K

13 × 25 - K

Aluminum

13 1/4 × 17 - K

13 1/2 × 15 - K

13 5/8 × 13 - K

1 2 3

14 × 11 - K

13 × 17 - K

13 × 19 - K

13 × 21 - K

13 × 23 - K

13 × 25 - K

13 1/2 × 14 - K

13 1/2 × 16 - K

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.

Stainless

S6D81020

CAUTION:

This is a 4-stroke engine. Never use premixed fuel.

Checking the engine oil level

1. Check the engine oil level.

4 5 6

S60C1150

NOTE:

If the engine oil is below the minimum level mark b, add sufficient oil until the level is between a and b.

7 8

6D81G11

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)

1-6

GEN

INFO

General information

Checking the gear oil level

1. Check the gear oil level.

S60C1140

Checking the battery

1. Check the capacity, electrolyte level, and specified gravity of the battery.

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)

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 on the cylinder block.

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.

S6D81030

3. Check that the alignment mark a on the bushing is aligned with the alignment mark b on the bracket.

S6D81040

1-7

6D81G11

Predelivery checks

WARNING

The shift/throttle cable joint must be screwed in a minimum of 8.0 mm (0.31 in)

Checking the steering system

1. Check the steering friction for proper adjustment.

2. Check that the steering operates smoothly.

S69J3370

S69J1210

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.

1 2 3 4 5

S60C1200

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 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.

S60V1070

6 7 8 9

6D81G11

1-8

GEN

INFO

General information

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.

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

210

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.

S69J1240

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.

NOTE:

The test run is part of the break-in operation.

1-9

6D81G11

SPEC

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

1 2 3 4 5 6 7 8 9

6D81G11

SPEC

Specifications

General specifications

Item Unit

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,

33.0 (8.72, 7.26) at 6,000 r/min

Imp gal)/hr

Engine idle speed r/min 700 ± 50

Power unit

Type In-line, 4-stroke, DOHC, 16 valves Cylinder quantity 4 Total displacement cm

(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

Model

F90TR

2-1

6D81G11

General specifications

Item Unit

Fuel and oil

Fuel type Regular unleaded gasoline Fuel minimum rating RON

Engine oil 4-stroke motor oil Engine oil grade API

Engine oil quantity

(without oil filter replacement) L (US qt,

(with oil filter replacement) L (US qt,

Gear oil type GEAR CASE LUBE Gear oil grade SAE 90 Gear oil quantity cm

Bracket unit

Trim angle (at 12° boat transom)

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

CCA/SAE A 380 MCA/ABYC A 502 RC/SAE Minute 124

(*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

(*2)

(*1)

PON

SE, SF, SG, SH, or SJ

SAE

Imp qt)

(US oz,

Imp oz)

Degree –4 to 16

10W-30 or 10W-40

Model

F90TR

91 86

4.3 (4.55, 3.78)

4.5 (4.76, 3.96)

670 (22.7, 23.6)

1 2 3 4 5 6 7 8 9

6D81G11

2-2

SPEC

Specifications

Maintenance specification

Power unit

Item Unit

Power unit

Minimum compression pressure

Oil pressure

(*1)

(*2)

kPa

(kgf/cm2, psi)

(kgf/cm

, 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.

Model

F90TR

860 (8.6, 124.7)

2-3

6D81G11

Maintenance specification

Item Unit

Oil ring

Dimension B mm (in) 2.38–2.48 (0.0937–0.0976) Dimension T 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)

(*)

mm (in) 2.40 (0.0945)

Model

F90TR

1 2 3 4 5 6 7 8 9

(*)

The figure is for reference only.

6D81G11

2-4

SPEC

Specifications

Item Unit

Valve lifters

Valve lifter outside diameter mm (in) 27.965–27.980 (1.1010–1.1016) Valve lifter-to-cylinder head

clearance

Valve shims

Valve shim thickness (in 0.025 mm increments)

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

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)

mm (in) 0.020–0.056 (0.0008–0.0022)

mm (in) 2.0–3.3 (0.08–0.13)

mm (in) 0.024–0.044 (0.0009–0.0017)

Model

F90TR

2-5

6D81G11

Maintenance specification

Item Unit

Oil pump

Discharge at 97–103 °C (207–217 °F) with 10W-30 engine oil

Pressure at 97–103 °C (207–217 °F) with 10W-30 engine oil

Relief valve opening pressure kPa

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)

Lower unit

Item Unit

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

Electrical

L (US gal,

Imp gal)/min

kPa

(kgf/cm

, psi)

5.9 (1.559, 1.298) at 1,000 r/min

118.0 (1.18, 17.1) at 1,000 r/min

441–539 (4.41–5.39, 63.9–78.2)

Model

F90TR

Model

F90TR

1 2 3 4 5

Item Unit

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) 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

Ω

1.53–2.07

Model

F90TR

6 7 8 9

6D81G11

2-6

SPEC

Specifications

Item Unit

Model

F90TR

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

(*)

Ω

459–561

(W/R, W/B – B)

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

, 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.

2-7

6D81G11

Maintenance specification

Item Unit

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

at 20 °C (68 °F)

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) Resistance (P – B)

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.

(*)

(W – W)

Ω

0.24–0.36

Ω

9–378.8

Model

F90TR

1 2 3 4 5 6

6D81G11

7 8 9

2-8

SPEC

Dimensions

Exterior

Specifications

mm (in)

35˚

204 (9.4)

405 (15.9)

857 (33.7)

666 (26.2)

L : 536 (21.1)

X: 663 (26.1)

171 (6.73)

366 (14.4)

49 (1.9)

527 (20.7)

164 (6.5)

27 (1.1)

L: 998 (39.3) X: 1,115 (43.9)

651 (25.6)

62 (2.4)

2-9

L: 917 (36.1)

X: 1,044 (41.1)

191 (7.5)

L : 25 (1.0)

X: 24 (0.9)

63 (2.5)

12˚

66˚

4˚

574 (22.6)28 (1.1)

L: 766 (30.2)

X: 842 (33.1)

S6D82010

6D81G11

Clamp bracket

180 (7.1)

Maintenance specification

mm (in)

1 2

180 (7.1)

163.5 (6.4)163.5 (6.4)

50.8 (2.0)

348.5 (13.7)

125.4 (4.9)125.4 (4.9)

13 (0.5)

254 (10.0)

18.5 (0.7)

55.5 (2.2)

80 (3.1)

4 5 6 7 8

6D81G11

S6D82020

2-10

SPEC

Specifications

Tightening torques

Specified torques

Part to be tightened Thread size

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

2nd 42 4.2 31.0

M10

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

2nd 17 1.7 12.5

Cylinder head cover plate screw M4 2 0.2 1.5

Cylinder head cover bolt

1st

2nd 8 0.8 5.9

Tightening torques

N·mkgf·mft·lb

42 4.2 31.0

80.85.9

2-11

6D81G11

Tightening torques

Part to be tightened Thread size

1st

2nd 28 2.8 20.7

Cylinder head bolt

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

Anode screw M4 2 0.2 1.5 Exhaust cover plug M18 55 5.5 40.6

Crankcase bolt

Connecting rod cap bolt

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

1st

2nd 30 3.0 22.1

3rd 90°

1st

2nd 12 1.2 8.9

1st

2nd 28 2.8 20.7

1st

2nd 60°

1st

2nd 80°

M10

Tightening torques

N·mkgf·mft·lb

14 1.4 10.3

15 1.5 11.1

60.64.4

14 1.4 10.3

19 1.9 14.0

18 1.8 13.3

1 2 3 4 5 6 7 8 9

6D81G11

2-12

SPEC

Specifications

Part to be tightened Thread size

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

Lever bolt M3 2 0.2 1.5 Manual valve — 20.21.5

Gear pump bracket bolt

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

M4 4 0.4 3.0 M5 5 0.5 3.7

M3 2 0.2 1.5 M5 4 0.4 3.0

Tightening torques

N·mkgf·mft·lb

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

2-13

6D81G11

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-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

1 2 3 4 5

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

6 7 8 9

6D81G11

CHK

ADJ

Periodic checks and adjustments

Special service tools

Digital tachometer YU-39951-B

Battery powered timing light YM-33277-A

Pressure/vacuum tester YB-35956-A

Oil filter wrench YU-38411

3-1

6D81G11

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.

Initial Every

Item Remarks

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) Fuel system Check 3-3 Gear oil Change 3-12 Lubrication points Lubricate 3-15 Engine idle speed

(EFI models) 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 Water pump Check 6-9 Engine oil Check/change 3-4 Oil filter Change 3-5 Spark plugs Clean/adjust/

Timing belt Check/replace 3-6

Check/replace 3-3

Check/adjust 3-8

replace

10 hours

(1 month)

50 hours

(3 months)

100 hours

(6 months)

200 hours

(1 year)

Refer to

page

3-6

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.

Every

Item Remarks

Timing belt Replace 5-13 Valve clearance (DOHC) Check/adjust 5-10

NOTE:

When using lead or high-sulfur gasoline, checking valve clearance may be required more frequently than every 500 hours.

6D81G11

500 hours

(2.5 years)

1,000 hours

(5 years)

Refer to

page

3-2

7 8 9

CHK

ADJ

Periodic checks and adjustments

Top cowling

Checking the top cowling

1. Check the fitting by pushing the cowling with both hands. Adjust if necessary.

S60C3010

2. Loosen the bolts 1.

3. Move the hook 2 up or down slightly to adjust its position.

2. Check the low-pressure fuel hose connections and fuel joint for leaks. Replace if necessary. Also, check the fuel filter 1, fuel pump 2, strainer 3, and fuel cooler

for leaks or deterioration. Replace if

necessary.

3. Check the high-pressure fuel hose connections for leaks. Replace if necessary. Also, check the vapor separator 5, fuel rail 6, fuel injectors 7, and pressure regulator 8 for leaks or deterioration. Replace if necessary.

S6D83010

NOTE:

• To loosen the fitting, move the hook in direction a.

• To tighten the fitting, move the hook in direction b.

4. Tighten the bolts.

5. Check the fitting again and, if necessary,

repeat steps 2–4.

Fuel system

Checking the fuel joint and fuel hoses (fuel joint-to-fuel injector)

1. Remove the flywheel magnet cover.

S6D83020

Checking the fuel filter

1. Check the fuel filter element 1 for dirt and residue and check the fuel filter cup

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.

S6D83030

3-3

6D81G11

Top cowling / Fuel system / Power unit

Power unit

Checking the engine oil

1. Place the outboard motor in an upright position.

2. Remove the oil dipstick, wipe it clean, and then insert it back into the dipstick hole.

3. Remove the oil dipstick again to check the oil level and to check the oil for discoloration and its viscosity.

S60C1150

1 2

4. Operate the oil changer to extract the oil.

NOTE:

Be sure to clean up any oil spills.

5. Pour the specified amount of the recommended engine oil into the oil filler hole.

3 4

NOTE:

• Change the oil if it appears milky or dirty.

• If the engine oil is below the minimum level

mark b, add sufficient oil until the level is between a and b.

Changing the engine oil using an oil changer

1. Start the engine, warm it up, and then turn it off.

2. Remove the oil dipstick and oil filler cap

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)

6. Install the oil filler cap and oil dipstick, and then start the engine and warm it up for 5 minutes.

7. Turn the engine off, and then check the oil level and correct it if necessary.

Changing the engine oil by draining it

1. Start the engine, warm it up, and then turn it off.

5 6 7 8

S60C3060

3. Insert the tube of the oil changer 2 into the dipstick hole 3.

6D81G11

3-4

CHK

ADJ

Periodic checks and adjustments

2. Remove the oil dipstick and oil filler cap

S60C3060

3. Place a drain pan under the drain hole, and then remove the drain bolt 2 and let the oil drain completely.

7. Turn the engine off, and then check the oil level and correct it if necessary.

Replacing the oil filter

1. Extract the engine oil with an oil changer or drain it.

2. Place a rag under the oil filter, and then remove the oil filter using the oil filter wrench.

S6D83050

NOTE:

• Wait more than 5 minutes after turning the

engine off to replace the oil filter.

• Be sure to clean up any oil spills.

NOTE:

Be sure to clean up any oil spills.

4. Install the drain bolt, and then tighten it to the specified torque.

Engine oil drain bolt:

27 N·m (2.7 kgf·m, 20.0 ft·lb)

5. Pour the specified amount of the recommended engine oil into the oil filler hole.

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)

6. Install the oil filler cap and oil dipstick, and then start the engine and warm it up for 5 minutes.

Oil filter wrench: YU-38411

3. Apply a thin coat of engine oil to the Oring of the new oil filter.

4. Install the oil filter, and then tighten it to the specified torque using the oil filter wrench.

3-5

6D81G11

Power unit

2. While turning the flywheel magnet clockwise, check the interior a and the exterior b of the timing belt for cracks, damage, or wear. Replace if necessary.

S6D83060

Oil filter:

18 N·m (1.8 kgf·m, 13.3 ft·lb)

5. Pour the specified amount of the recommended engine oil into the oil filler hole.

Recommended engine oil:

4-stroke motor oil API: SE, SF, SG, SH, or SJ SAE: 10W-30 or 10W-40

Engine oil quantity:

With oil filter replacement:

4.5 L (4.76 US qt, 3.96 Imp qt)

NOTE:

For replacement procedures, see Chapter 5, “Replacing the timing belt.”

Checking the spark plugs

1. Remove the spark plug wire cover.

2. Disconnect the spark plug wires, and then remove the spark plugs.

3. Clean the electrodes 1 with a spark plug cleaner or wire brush. Replace the spark plug if necessary.

S6D83070

1 2 3 4 5 6

6. Install the oil filler cap and oil dipstick, and then start the engine and warm it up for 5 minutes.

7. Turn the engine off, and then check the oil level and correct it if necessary.

Checking the timing belt

CAUTION:

Do not turn the flywheel magnet counterclockwise, otherwise the valve system may be damaged.

1. Remove the flywheel magnet cover.

6D81G11

4. Check the electrodes for erosion and excessive carbon or other deposits, and the gasket for damage. Replace the spark plug if necessary.

3-6

7 8 9

CHK

ADJ

5. Check the spark plug gap a. Adjust if out of specification.

Periodic checks and adjustments

Specified spark plug:

LFR5A-11 (NGK)

Spark plug gap a:

1.0–1.1 mm (0.039–0.043 in)

6. Install the spark plugs, tighten them finger tight, then to the specified torque using a spark plug wrench.

Spark plug:

25 N·m (2.5 kgf·m, 18.4 ft·lb)

S6D83080

3. Suspend the thermostat in a container of water.

4. Place a thermometer in the water and slowly heat the water.

7. Install the spark plug wire cover.

Spark plug wire cover screw:

4 N·m (0.4 kgf·m, 3.0 ft·lb)

Checking the thermostat

1. Remove the flywheel magnet cover.

2. Disconnect the cooling water hose 1, and then remove the thermostat cover and thermostat 3.

S69J5E40

5. Check the thermostat valve opening at the specified water temperatures. Replace if out of specification.

3-7

6D81G11

Power unit / Control system

Water

temperature

58–62 °C

(136–144 °F)

above

70 °C (158 °F)

6. Install the thermostat and cover.

7. Connect the cooling water hose, and then install the flywheel magnet cover.

Checking the cooling water passage

1. Check the cooling water inlet cover and cooling water inlet for clogs. Clean if necessary.

Valve lift a

0.05 mm

(0.0020 in)

(valve begins to lift)

more than

4.3 mm (0.17 in)

Control system

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.

1 2

3 4

S62Y3320

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.

S60C3450

Digital tachometer: YU-39951-B

Engine idle speed: 700 ± 50 r/min

Adjusting the throttle link and throttle cable

1. Remove the intake silencer.

2. Set the remote control lever to the neutral position and fully close the throttle lever.

6D81G11

3-8

CHK

ADJ

3. Loosen the locknut 1, remove the clip

, and then disconnect the throttle cable

joint 3.

4. Loosen the locknut 4, and then disconnect the throttle link rod joint 5 from the ball joint of the throttle body.

Periodic checks and adjustments

S6D83110

8. Adjust the throttle link rod joint to align its hole with the ball joint 0 on the throttle body.

S6D83090

5. Check that the stopper 6 on the throttle cam contacts the fully closed stopper

on the cylinder block.

S6D83100

6. Check that the throttle valve fully close.

NOTE:

Do not turn the throttle stop screw.

S6D83120

9. Connect the throttle link rod joint, and then tighten the locknut.

10. Operate the throttle cam to check that the throttle valve fully closes and fully opens, and check that the gap

between the stopper A on the throttle lever and fully open stopper B on the throttle body is less than 5 mm (0.20 in) when the throttle cam is in the fully open position.

7. Push the throttle link rod 8 toward the cylinder head and check that the throttle cam roller 9 contacts the side a of the throttle cam.

3-9

S6D83130

11. Adjust the position of the throttle cable joint until its hole is aligned with the set pin on the throttle cam.

6D81G11

Control system

5. Align the alignment mark a on the bushing and alignment mark b on the bracket.

WARNING

The throttle cable joint must be screwed in a minimum of 8.0 mm (0.31 in) c.

12. Connect the throttle cable joint, install the clip, and then tighten the locknut.

13. Check the throttle cable for smooth operation and, if necessary, repeat steps 2–

12.

14. Install the intake silencer.

Checking the gear shift operation

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.

S69J3370

S6D81040

6. Install the clip 4.

7. Adjust the position of the shift cable joint until its hole is aligned with the set pin.

WARNING

The shift cable joint must be screwed in a minimum of 8.0 mm (0.31 in) c.

S69J3370

1 2 3 4 5 6

3. Loosen the locknut 1, remove the clip

, and then disconnect the shift cable

joint 3.

4. Remove the clip 4.

6D81G11

S6D83140

8. Connect the cable joint, install the clip, and then tighten the locknut.

9. Check the gear shift for smooth operation and, if necessary, repeat steps 2–8.

3-10

7 8 9

CHK

ADJ

Periodic checks and adjustments

Bracket unit

Checking the power trim and tilt operation

1. Fully tilt the outboard motor up and down a few times and check the entire trim and tilt range for smooth operation. Check the power trim and tilt fluid level if necessary.

S6D83150

WARNING

After tilting up the outboard motor, be sure to support it with the tilt stop lever. Otherwise, the outboard motor could suddenly lower if the power trim and tilt unit should lose fluid pressure.

2. Remove the reservoir cap 2, and then check the fluid level in the reservoir.

NOTE:

Be sure to listen to the winding sound of the power trim and tilt motor for smooth operation.

2. Fully tilt the outboard motor up, and then support it with the tilt stop lever 1 to check the lock mechanism of the lever.

S6D83150

Checking the power trim and tilt fluid level

1. Fully tilt the outboard motor up, and then support it with the tilt stop lever 1.

S6D83160

NOTE:

If the fluid is at the correct level, the fluid should overflow out of the filler hole when the reservoir cap is removed.

3. If necessary, add sufficient fluid of the recommended type until it overflows out of the filler hole.

Recommended power trim and tilt fluid:

ATF Dexron II

4. Install the reservoir cap, and then tighten it to the specified torque.

Reservoir cap:

7 N·m (0.7 kgf·m, 5.2 ft·lb)

3-11

6D81G11

Bracket unit / Lower unit

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.

S60C3540

NOTE:

If the oil is at the correct level, the oil should overflow out of the check hole when the check screw is removed.

1 2

3. Check the oil for metal and discoloration, and its viscosity. Check the internal parts of the lower case if necessary.

3 4

3. If necessary, add sufficient gear oil of the recommended type until it overflows out of the check hole.

Recommended gear oil:

GEAR CASE LUBE SAE: 90

4. Install the check screw, and then tighten it to the specified torque.

Gear oil check screw:

9 N·m (0.9 kgf·m, 6.6 ft·lb)

Changing the gear oil

1. Tilt the outboard motor up slightly.

2. Place a drain pan under the drain screw

, remove the drain screw, then the check screw 2 and let the oil drain completely.

5 6 7 8

6D81G11

3-12

CHK

ADJ

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.

Periodic checks and adjustments

Pressure/vacuum tester:

YB-35956-A

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.

Recommended gear oil:

GEAR CASE LUBE SAE: 90

Gear oil quantity:

670 cm

(22.7 US oz, 23.6 Imp oz)

5. Install the check screw and quickly install the drain screw, and then tighten them to the specified torque.

Gear oil check screw and drain

screw:

9 N·m (0.9 kgf·m, 6.6 ft·lb)

Checking the lower unit for air leakage

1. Remove the check screw 1, and then install the special service tool.

NOTE:

Cover the check hole with a rag when removing the tester from the lower unit.

Lower unit holding pressure:

100 kPa (1.0 kgf/cm

, 14.5 psi)

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.

3-13

6D81G11

Lower unit / General

General

Checking the anodes

1. Check the anodes and trim tab for scales, grease, or oil. Clean if necessary.

NOTE:

If it is necessary to disassemble the outboard motor to check an anode, refer to the applicable disassembly procedure in this manual.

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.

2 3 4

S6D83170

S6D83210

S62Y3640

S69J3620

5 6 7 8

CAUTION:

Do not oil, grease, or paint the anodes or the trim tab, otherwise they will be ineffective.

6D81G11

3-14

CHK

ADJ

Periodic checks and adjustments

2. Check the specific gravity of the electrolyte. Fully charge the battery if out of 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.

S60C3660

S60C3670

S6D83180

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)

3-15

S60C3695

6D81G11

General

S60C3710

NOTE:

Apply grease to the grease nipple until it flows from the bushings a.

2. Apply low temperature resistant grease

to the area shown.

2 3 4 5 6

S6D83190

3. Apply corrosion resistant grease to the

area shown.

6D81G11

7 8 9

3-16

FUEL

Fuel system

Special service tools .....................................................................................4-1

Hose routing...................................................................................................4-2

Fuel and blowby hoses..............................................................................4-2

Fuel filter and fuel pump ...............................................................................4-3

Checking the fuel pump.............................................................................4-5

Disassembling the fuel pump ....................................................................4-5

Checking the diaphragm and valves .........................................................4-6

Assembling the fuel pump .........................................................................4-6

Intake manifold...............................................................................................4-7

Checking the throttle position sensor ........................................................4-9

Installing the throttle position sensor .........................................................4-9

Checking the idle speed control ................................................................4-9

Vapor separator............................................................................................4-10

Reducing the fuel pressure......................................................................4-13

Disconnecting the quick connector..........................................................4-13

Measuring the fuel pressure ....................................................................4-13

Checking the pressure regulator .............................................................4-14

Draining the fuel ......................................................................................4-15

Removing the fuel hose clamp ................................................................4-15

Installing the fuel hose clamp ..................................................................4-15

Disassembling the vapor separator .........................................................4-15

Checking the vapor separator .................................................................4-16

Assembling the vapor separator..............................................................4-16

Adjusting the float ....................................................................................4-17

1 2 3 4 5 6

6D81G11

Canister.........................................................................................................4-18

Checking the canister ..............................................................................4-19

7 8 9

FUEL

Fuel system

Special service tools

Pressure/vacuum tester YB-35956-A

Fuel pressure gauge YB-06766

Fuel pressure gauge adapter B YB-06942

4-1

6D81G11

Special service tools / Hose routing

Hose routing

Fuel and blowby hoses

1 2 3 4

Blowby hose

Fuel hose (primary pump-to-fuel filter)

Fuel hose (fuel filter-to-fuel pump)

Fuel hose (fuel pump-to-strainer)

Fuel hose (strainer-to-vapor separator)

High-pressure fuel hose (vapor separator-to-fuel rail)

Fuel hose (pressure regulator-to-fuel cooler)

Fuel hose (fuel cooler-to-vapor separator)

Canister hose (vapor separator-to-canister)

Canister hose (canister-to-idle speed control)

Canister hose (canister-to-filter)

Canister hose (filter-to-bottom cowling)

5 6 7 8 9

6D81G11

4-2

FUEL

Fuel system

Fuel filter and fuel pump

10 N

m (1.0 kgf

m, 7.4 ft

Ib)

5 6

3 N

m (0.3 kgf

No. Part name Q’ty Remarks

1Nut 1 2 Fuel filter assembly 1 3O-ring 1 4 Fuel filter element 1 5O-ring 1 6Float 1 7Cup 1 8 Fuel hose 1

9 Fuel pump 1 10 Bolt 2 M6 × 30 mm 11 Fuel hose 1 12 Strainer 1 13 Bolt 1 M6 × 12 mm 14 Bracket 1 15 O-ring 1

m, 2.2 ft

Ib)

Not reusable

S6D84020

4-3

6D81G11

Fuel filter and fuel pump

4 N

m (0.4 kgf

m, 3.0 ft

Ib)

2 3

No. Part name Q’ty Remarks

1Screw 3 ø6 × 35 mm

2 Cover 1

3Gasket 1

4 Fuel pump body 2 assembly 1

5 Diaphragm 1

6Pin 1

7Spring 1

8 Fuel pump body 1 1

9Spring 1 10 Plunger 1 11 Nut 3

Not reusable

S6D84030

6 7 8 9

6D81G11

4-4

FUEL

Fuel system

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.

S63P4090

6. Apply the specified positive pressure and check that there is no air leakage. Disassemble the fuel pump if necessary.

S63P4110

NOTE:

Assemble the fuel pump valve 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

, 7.3 psi)

Pressure/vacuum tester:

YB-35956-A

Specified pressure:

50 kPa (0.5 kgf/cm

, 7.3 psi)

4. Apply the specified negative pressure and check that there is no air leakage.

S63P4100

Specified pressure:

30 kPa (0.3 kgf/cm

, 4.4 psi)

Disassembling the fuel pump

1. Disassemble the fuel pump.

2. Push down on the plunger and the diaphragm, turn fuel pump body 1 approximately 90° to a position where the pin 2 can be removed easily, and then remove the pin.

5. Connect the special service tool to the fuel pump outlet.

4-5

6D81G11

3. Slowly let up on the plunger and diaphragm, and then remove them.

Checking the diaphragm and valves

1. Check the diaphragm for tears and the valves for cracks. Replace if necessary.

Assembling the fuel pump

NOTE:

Clean the parts and soak the valves and the diaphragm in gasoline before assembly to obtain prompt operation of the fuel pump when starting the engine.

Fuel filter and fuel pump

1 2

1. Align the plunger and diaphragm installation holes a, and then install the plunger into the diaphragm.

2. Push down on the plunger and the diaphragm, and then install the pin 1.

3. Turn fuel pump body 1 2 approximately 90°, and then push down on the plunger several times to make sure that the pin does not come out.

3 4 5 6 7

NOTE:

Make sure that the gasket and diaphragm are kept in place through the assembly process.

6D81G11

8 9

4-6

FUEL

Fuel system

Intake manifold

No. Part name Q’ty Remarks

1 Intake silencer 1 2Bolt 2 M6 × 80 mm 3 Bushing 4 4 Collar 2 5 Intake manifold assembly 1 6Bolt 4 M8 × 30 mm 7 Collar 5 8Bolt 1 M8 × 100 mm

9Spacer 1 10 Bolt 3 M6 × 45 mm 11 Collar 3 12 Holder 1 13 Gasket 1 14 Pin 2 15 Joint 1

Not reusable

S6D84040

4-7

6D81G11

Intake manifold

3.7 N

m (0.37 kgf

m, 2.7 ft

lb)

m (0.8 kgf

8 N

m, 5.9 ft

Ib)

1 2 3

8 N

m (0.8 kgf

No. Part name Q’ty Remarks

1 Intake manifold 1

2 Sensor assembly 1

3Screw 4 ø5 × 13 mm

4O-ring 1

5 Idle speed control 1

6O-ring 1

7 Throttle body assembly 1

8Bolt 3 M6 × 16 mm

9Gasket 1 10 Throttle position sensor 1 11 Screw 2 12 O-ring 1 13 Fuel injector 4 14 O-ring set 4 15 Fuel rail 1 16 Bolt 1 M6 × 38 mm

m, 5.9 ft

Ib)

Not reusable

S6D84050

6 7 8 9

6D81G11

4-8

FUEL

Fuel system

Checking the throttle position sensor

1. Check the throttle position sensor output voltage using the Yamaha Diagnostic System. If the output voltage is out of specification, replace the throttle position sensor.

Throttle position sensor output voltage at engine idle speed:

0.8–1.2 V

Installing the throttle position sensor

1. Install the throttle position sensor 1 in a position where the output voltage is within specification.

S6D84170

NOTE:

• If the throttle position sensor output voltage

is out of specification, reinstall the throttle position sensor.

• Measure the throttle position sensor output

voltage using the Yamaha Diagnostic System.

• Do not turn the throttle stop screw a.

Throttle position sensor output voltage at engine idle speed:

0.8–1.2 V

Checking the idle speed control

1. Check the operation of the idle speed control using the Yamaha Diagnostic System.

4-9

6D81G11

Intake manifold / Vapor separator

Vapor separator

No. Part name Q’ty Remarks

1 Vapor separator 1 2Bolt 3 M6 × 30 mm 3Grommet 3 4 Collar 3 5 Fuel hose 1 6 Fuel inlet hose 1 7Hose 1 8 Joint 1

9Hose 1 10 Hose 1 11 Hose 1 12 Hose 1 13 Clamp 1 14 Clamp 1 15 Quick connector 1 16 Clamp 1 17 Plastic tie 5

Not reusable

S6D84070

6 7 8 9

6D81G11

4-10

FUEL

Fuel system

1.5 N

m (0.15 kgf

m, 1.1 ft

lb)

3 N

m (0.3 kgf

m, 2.2 ft

Ib)

3 N

m (0.3 kgf

m, 2.2 ft

Ib)

1616

4 N

m (0.4 kgf

No. Part name Q’ty Remarks

1Screw 6 ø5 × 14 mm

2Gasket 1

3 Float chamber 1

4Damper 1

5Drain screw 1

6O-ring 1

7 Joint screw 1

8O-ring 1

9 Fuel hose 1 10 Fuel cooler 1 11 Screw 2 ø6 × 15 mm 12 Fuel hose 1 13 Hose 1 14 Hose 1 15 Hose 1 16 Plastic tie 8

m, 3.0 ft

Ib)

Not reusable

S6D84080

4-11

6D81G11

Vapor separator

10 N

4 N

m (1.0 kgf

m (0.4 kgf

5 N

m, 3.0 ft

m (0.5 kgf

m, 7.4 ft

Ib)

m, 3.7 ft

271

Ib)

2 N

m (0.2 kgf

m, 1.5 ft

Ib)

2 3

4 5

2 N

m (0.2 kgf

No. Part name Q’ty Remarks

1 Cover 1

2 Pressure regulator 1

3Bolt 2 M6 × 12 mm

4O-ring 1

5 Joint screw 1

6O-ring 1

7 Electric fuel pump 1

8Grommet 1

9 Collar 1 10 Filter 1 11 Screw 3 ø4 × 6 mm 12 Wiring harness 1 13 Float 1 14 Needle valve 1 15 Pin 1 16 Cap 1

m, 1.5 ft

Ib)

Not reusable

S6D84090

6 7 8 9

6D81G11

4-12

FUEL

Fuel system

Reducing the fuel pressure

1. Remove the cap 1.

2. Cover the pressure check valve a of the vapor separator with a rag, and then press in the pressure check valve using a thin screwdriver to release the fuel pressure.

CAUTION:

• Do not rotate the quick connector tab past the stopper position a, otherwise it could be damaged.

• When the fuel hose is disconnected, quickly remove the retainer 2 from the quick connector, otherwise the retainer could be lost.

2. Disconnect the quick connector 3 from

the fuel rail 4 directly.

S6D84180

WARNING

Always reduce the fuel pressure in the high-pressure fuel line before servicing the line or the vapor separator. If the fuel pressure is not released, pressurized fuel may spray out.

Disconnecting the quick connector

1. Wrap the quick connector with a cloth, and then rotate the quick connector tab

to the stopper position a.

S6C14240

WARNING

If the quick connector is removed suddenly, pressurized fuel could spray out. To gradually release the fuel pressure, be sure to remove the quick connector slowly.

S6C14250

WARNING

Always reduce the fuel pressure in the fuel line before servicing the line or the fuel pipe. If the fuel pressure is not released, pressurized fuel could spray out.

Measuring the fuel pressure

1. Disconnect the quick connector from the fuel rail.

NOTE:

Before disconnecting the quick connector, release the fuel pressure.

2. Connect fuel pressure gauge adapter B

between the quick connector and fuel

rail.

3. Connect the fuel pressure gauge 2 to fuel pressure gauge adapter B.

4-13

6D81G11

Vapor separator

S6D84110

WARNING

• When connecting the fuel pressure gauge, first cover the connection between the gauge and the adapter with a clean, dry rag to prevent fuel from leaking out.

• Gently screw in the gauge until it is firmly connected.

Fuel pressure gauge adapter B 1:

YB-06942

Fuel pressure gauge 2: YB-06766

Fuel pressure (reference data):

230 kPa (2.3 kgf/cm

Checking the pressure regulator

1. Disconnect the quick connector from the fuel rail.

NOTE:

Before disconnecting the quick connector, release the fuel pressure.

2. Connect fuel pressure gauge adapter B between the quick connector and fuel rail.

3. Connect the fuel pressure gauge to fuel pressure gauge adapter B.

4. Disconnect the pressure regulator hose, and then connect the special service tools to the pressure regulator.

, 33.4 psi)

1 2 3 4

4. Turn the engine start switch to ON, and then measure the fuel pressure within 3 seconds.

NOTE:

The fuel pressure decreases 3 seconds after the engine start switch is turned to ON.

Fuel pressure (reference data):

300 kPa (3.0 kgf/cm

5. Measure the fuel pressure 3 seconds after turning the engine start switch to ON.

Fuel pressure (reference data):

260 kPa (2.6 kgf/cm

6. Start the engine, warm it up for 5 minutes, and then measure the fuel pressure. If below specification, check the high-pressure fuel line and the vapor separator.

, 43.5 psi)

, 37.7 psi)

S6D84120

WARNING

• When connecting the fuel pressure gauge, first cover the connection between the gauge and the adapter with a clean, dry rag to prevent fuel from leaking out.

• Gently screw in the gauge until it is firmly connected.

Fuel pressure gauge: YB-06766 Fuel pressure gauge adapter B:

YB-06942

Pressure/vacuum tester:

YB-35956-A

5 6 7 8 9

6D81G11

5. Start the engine and let it idle.

4-14

FUEL

Fuel system

6. Check that the fuel pressure reduces when vacuum pressure is applied to the pressure regulator. If the fuel pressure does not reduce, replace the pressure regulator.

NOTE:

When the vacuum pressure reaches the specified level, the fuel pressure reduces.

Draining the fuel

1. Remove the cap 1.

2. Cover the pressure check valve a of the vapor separator with a rag, and then press in the pressure check valve using a thin screwdriver to release the fuel pressure.

WARNING

Reduce the fuel pressure before loosening the vapor separator drain screw, or pressurized fuel will spray out and may result in serious injury.

Removing the fuel hose clamp

1. Remove the fuel hose clamp by cutting the crimped section of the clamp.

WARNING

Always reduce the fuel pressure in the high-pressure fuel line before servicing the line or the vapor separator. If the fuel pressure is not released, pressurized fuel may spray out.

3. Place a container under the vapor separator drain hose, and then loosen the drain screw 2.

4. Drain the fuel from the vapor separator drain hose by pressing the pressure check valve using a thin screwdriver.

CAUTION:

If the fuel hose clamp is removed without cutting the crimp first, the fuel hose will be damaged.

Installing the fuel hose clamp

1. Crimp the fuel hose clamp properly to securely fasten it.

4-15

S6D84100

WARNING

Do not reuse the fuel hose clamp, always replace it with a new one.

Disassembling the vapor separator

1. Remove the float chamber, float pin, and float.

6D81G11

Vapor separator

S6C14220

NOTE:

Remove the float pin in the direction of the arrow a shown.

2. Remove the needle valve and other components.

Checking the vapor separator

1. Check the needle valve for bends or wear. Replace if necessary.

S6C14210

NOTE:

• Do not reuse the float pin, always replace it with a new one.

• Install the float pin in the direction of the arrow a shown.

• Install the float pin with its tapered end towards the punch mark b on the vapor separator cover.

2. Check the float height c as shown.

Adjust the float height if out of specification.

1 2 3 4 5

S6D54200

2. Check the float for deterioration. Replace if necessary.

3. Check the filter for dirt or residue. Clean if necessary.

Assembling the vapor separator

1. Install the needle valve, float, and float pin, and then check the float for smooth operation.

Float height c:

46.6 ± 1.0 mm (1.83 ± 0.04 in)

6 7 8 9

6D81G11

4-16

FUEL

Fuel system

3. Check the float height d as shown. Adjust the float height if out of specification.

S6C14200

Float height d:

35.0 ± 1.0 mm (1.38 ± 0.04 in)

NOTE:

• The float should be resting on the needle

valve, but not compressing it.

• Take measurements at the position shown,

opposite the float pivot.

Float height d:

35.0 ± 1.0 mm (1.38 ± 0.04 in)

4. Install the float chamber.

Float chamber screw:

3 N·m (0.3 kgf·m, 2.2 ft·lb)

Adjusting the float

1. Adjust the stopper a of the float by bending it until the float height b is within specification.

NOTE:

When adjusting the float height, do not bend the lever e.

Float height b:

46.6 ± 1.0 mm (1.83 ± 0.04 in)

2. Adjust the lever c of the float by bending it until the float height d is within specification.

4-17

6D81G11

Vapor separator / Canister

Canister

3 4

No. Part name Q’ty Remarks

1Bolt 1 M6 × 16 mm 2Bracket 1 3 Canister 1 4Bolt 2 M6 × 28 mm 5Grommet 2 6Bracket 1 7 Collar 2 8Hose 1

9Hose 1 10 Hose 1 11 Filter 1 12 Hose 1 13 Clamp 1 14 Bolt 1 M6 × 10 mm 15 Holder 1 16 Bolt 1 M6 × 16 mm 17 Bracket 1

S6D84150

6 7 8 9

6D81G11

4-18

FUEL

Fuel system

Checking the canister

1. Check the canister for cracks. Replace if necessary.

2. Connect the special service tool to the atmospheric port 1 and cover the other ports, each with a finger.

S6D84160

3. Apply the specified positive pressure and check that there is no air leakage. Replace the canister if there is air leakage.

Pressure/vacuum tester:

YB-35956-A

Specified pressure:

19.6 kPa (0.196 kgf/cm

, 2.8 psi)

4-19

6D81G11

POWR

Power unit

Special service tools .....................................................................................5-1

Power unit.......................................................................................................5-3

Checking the compression pressure .........................................................5-3

Checking the oil pressure ..........................................................................5-3

Checking the valve clearance..................................................................5-10

Replacing the timing belt .........................................................................5-13

Removing the power unit.........................................................................5-16

Removing the timing belt and sprockets..................................................5-17

Checking the timing belt and sprockets...................................................5-18

Installing the sprockets and timing belt....................................................5-18

Throttle link...................................................................................................5-20

ECM ...............................................................................................................5-21

Junction box.................................................................................................5-22

Cylinder head ...............................................................................................5-24

Removing the cylinder head ....................................................................5-26

Checking the valve lifters.........................................................................5-27

Checking the valve springs......................................................................5-27

Checking the valves ................................................................................5-27

Checking the valve guides.......................................................................5-28

Replacing the valve guides......................................................................5-28

Checking the valve seat ..........................................................................5-29

Refacing the valve seat ...........................................................................5-30

Checking the camshafts ..........................................................................5-31

Checking the cylinder head .....................................................................5-32

Installing the valves .................................................................................5-33

Installing the cylinder head ......................................................................5-33

Exhaust cover ..............................................................................................5-36

Removing the exhaust cover ...................................................................5-38

Checking the pressure control valve .......................................................5-38

Installing the pressure control valve ........................................................5-38

Installing the exhaust cover .....................................................................5-38

6D81G11

Cylinder block ..............................................................................................5-39

Disassembling the cylinder block ............................................................5-40

Checking the piston diameter ..................................................................5-40

Checking the cylinder bore ......................................................................5-41

Checking the piston clearance ................................................................5-41

Checking the piston rings ........................................................................5-41

Checking the piston ring grooves ............................................................5-42

Checking the piston ring side clearance..................................................5-42

Checking the connecting rod big end side clearance..............................5-43

Checking the crankshaft ..........................................................................5-43

Checking the crankpin oil clearance........................................................5-43

Selecting the connecting rod bearing ......................................................5-45

Checking the crankshaft journal oil clearance .........................................5-46

Selecting the main bearing ......................................................................5-47

Assembling the power unit ......................................................................5-49

Installing the power unit...........................................................................5-51

1 2 3 4 5 6 7 8 9

6D81G11

POWR

Power unit

Special service tools

Compression gauge YU-33223

Compression gauge extension YB-06563

Valve spring compressor YM-01253 Valve spring compressor attachment YB-06320

Valve guide remover/installer YM-04064-A

Flywheel magnet holder YB-06139

Universal puller YB-06117

Crankshaft holder YB-06552

Valve guide reamer YM-04066

Neway valve seat kit YB-91044

Piston ring compressor YM-08037

5-1

6D81G11

Oil filter wrench YU-38411

Special service tools

1 2 3 4 5 6 7 8

6D81G11

5-2

POWR

Power unit

Checking the compression pressure

1. Start the engine, warm it up for 5 minutes, and then turn it off.

2. Remove the engine stop lanyard from the engine stop lanyard switch on the remote control box.

3. Remove the spark plug wire cover and all spark plugs, and then install the special service tools into a spark plug hole.

S6D85110

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 valve clearance, valve, valve seat, cylinder head gasket, and cylinder head. Adjust or replace if necessary.

Checking the oil pressure

1. Remove the flywheel magnet cover.

2. Place a rag under the oil pressure switch.

3. Remove the oil pressure switch, and then

install an oil pressure gauge 1 to the oil pressure switch installation hole.

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 1: YU-33223 Compression gauge extension 2:

YB-06563

4. Fully open the throttle, crank the engine until the reading on the compression gauge stabilizes, and then check the compression pressure.

Minimum compression pressure (reference data):

860 kPa (8.6 kgf/cm

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 cylinder, and then check the pressure again.

, 124.7 psi)

S6D85120

NOTE:

Use a general pressure gauge.

4. Start the engine and warm it up for 5 minutes.

5. Check the oil pressure. Check the oil pump, oil leakage, and oil strainer if below specification.

Oil pressure (reference data):

510 kPa (5.1 kgf/cm

, 74.0 psi) at

engine idle speed

5-3

6D81G11

Power unit

572

No. Part name Q’ty Remarks

1Damper 1 2Grommet 2 3Grommet 1 4 Flywheel magnet cover 1 5 Power unit 1 6 Oil dipstick 1 7Gasket 1 8 Dowel 2

9Bolt 5 M6 × 16 mm 10 Bolt 6 M10 × 130 mm 11 Screw 2 ø6 × 40 mm 12 Nut 2 13 Apron 1 14 Bolt 2 M8 × 35 mm 15 Holder 1

572

4 N

m (0.4 kgf

m, 3.0 ft

Not reusable

1 42 N 2 42 N

Ib)

m (4.2 kgf

m, 31.0 ft

Ib)

S6D85010

3 4 5 6 7 8 9

6D81G11

5-4

POWR

Power unit

215 N

m (21.5 kgf

m, 158.6 ft

lb)

No. Part name Q’ty Remarks

1Nut 1

2 Washer 1

3 Flywheel magnet 1

4Screw 1 ø4 × 10 mm

5Screw 3 ø6 × 30 mm

6 Stator coil 1

7Bolt 4 M6 × 30 mm

8 Stator assembly 1

9 Collar 2 10 Bolt 1 M6 × 15 mm 11 Woodruff key 1 12 Bolt 1 M6 × 15 mm 13 Holder 1 14 Grommet 1

S6D85020

5-5

6D81G11

Power unit

265 N

No. Part name Q’ty Remarks

1 Timing belt 1

2 Bolt 2 M10 × 35 mm

3 Dowel 2

4 Driven sprocket 2

5Bolt 2 M6 × 15 mm

6Bracket 1

7 Bolt 1 M10 × 45 mm

8 Timing belt tensioner 1

9Spring 1 10 Plastic tie 1 11 Hose 1 12 Clamp 1 13 Nut 1 14 Drive sprocket 1 15 Plate 1 16 Woodruff key 1

m (26.5 kgf

39 N

m (3.9 kgf

m, 195.5 ft

m, 28.8 ft

lb)

Ib)

67F-46241-00

60 N

Not reusable

m (6.0 kgf

m, 44.3 ft

Ib)

S6D85030

2 3 4 5 6 7 8 9

6D81G11

5-6

POWR

Power unit

2 N

8 N

m (0.2 kgf

m (0.8 kgf

m, 1.5 ft

m, 5.9 ft

Ib)

572

29 N

4 N

m (2.9 kgf

m (0.4 kgf

m, 21.4 ft

m, 3.0 ft

Ib)

4 N

m (0.4 kgf

m, 3.0 ft

Ib)

9 N

m (0.9 kgf

No. Part name Q’ty Remarks

1Screw 5 ø6 × 30 mm

2 Cover 1

3 Spark plug wire 4

4 Holder 2

5 Holder 2

6Bolt 1 M6 × 12 mm

7 Holder 1

8 Clamp 1

9Hose 1 10 Plastic tie 1 11 Ignition coil 2 12 Bracket 2 13 Bolt 4 M6 × 25 mm 14 Holder 2 15 Starter motor 1 16 Bolt 3 M8 × 45 mm 17 Terminal 1

Not reusable

m, 6.6 ft

Ib)

S6D85040

5-7

6D81G11

Power unit

2 N

8 N

m (0.2 kgf

m (0.8 kgf

m, 1.5 ft

m, 5.9 ft

Ib)

572

29 N

4 N

m (2.9 kgf

m (0.4 kgf

m, 21.4 ft

m, 3.0 ft

Ib)

1 2

4 N

m (0.4 kgf

m, 3.0 ft

Ib)

9 N

m (0.9 kgf

No. Part name Q’ty Remarks

18 Nut 1 19 Cap 1 20 Positive battery lead 1 21 Nut 1 22 Negative battery lead 1 23 Bolt 1 M6 × 20 mm 24 Junction box cover 1 25 Bolt 1 M6 × 10 mm 26 Cap 1 27 Oil pressure switch 1 28 Bolt 1 M4 × 8 mm 29 Holder 1 30 Bolt 1 M6 × 25 mm 31 Clamp 1

m, 6.6 ft

Ib)

S6D85040

5 6 7 8 9

6D81G11

5-8

POWR

Power unit

1 8 N

2 17 N

•

m (0.8 kgf • m, 5.9 ft

•

m (1.7 kgf • m, 12.5 ft

•

lb)

•

S1280B

lb)

2 N

m (0.2 kgf

m, 1.5 ft

Ib)

S1280B

•

lb)

•

lb)

271

1 8 N

2 17 N

•

m (0.8 kgf • m, 5.9 ft

•

m (1.7 kgf • m, 12.5 ft

1 8 N

2 8 N

m (0.8 kgf

No. Part name Q’ty Remarks

1 Oil filler cap 1

2O-ring 1

3 Cylinder head cover 1

4Screw 8 ø4 × 8 mm

5Plate 1

6Grommet 2

7Gasket 1

8Bolt 14 M6 × 30 mm

9Camshaft cap 2 10 Camshaft cap 8 11 Bolt 4 M7 × 48 mm 12 Bolt 16 M7 × 37 mm 13 Oil seal 2 14 Camshaft 2

m, 5.9 ft

lb)

Not reusable

S6D85070

5-9

6D81G11

Checking the valve clearance

CAUTION:

• Do not turn the flywheel magnet counterclockwise, otherwise the valve system may be damaged.

• Do not remove the ignition timing pointer.

• Do not turn the flywheel magnet or the driven sprockets when the timing belt is not installed. Otherwise the piston and valves will interfere with each other and be damaged.

Power unit

1 2

NOTE:

For removal and installation procedures of the timing belt, driven sprockets, and camshafts, see the applicable procedures in this manual.

1. Remove the flywheel magnet cover 1,

filter 2, and spark plug wire cover 3, disconnect the spark plug wires 4, fuel hoses 5, and blowby hose 6, and then remove all spark plugs.

S6D85130

S6D85140

3. Loosen the tensioner bolt 7, and then remove the spring 8, timing belt 9, driven sprockets 0, and cylinder head cover A.

3 4 5 6 7

2. Turn the flywheel magnet clockwise and align the “TDC” mark a on the flywheel magnet with the pointer b, and check that “” marks c and d on the driven sprockets are aligned.

6D81G11

S6D85150

5-10

8 9

POWR

Power unit

4. Install the driven sprockets 0, timing belt

, and spring 8, and then tighten the

tensioner bolt.

Valve clearance (cold):

Intake

0.20 ± 0.03 mm (0.008 ± 0.001 in)

Exhaust f:

0.34 ± 0.03 mm (0.013 ± 0.001 in)

6. Turn the flywheel magnet 360° clockwise.

7. Check the intake valve clearance for cylinders #3 and #4, and the exhaust valve clearance for cylinders #2 and #4. Adjust if out of specification.

S6D85160

5. Check the intake valve clearance for cylinders #1 and #2, and the exhaust valve clearance for cylinders #1 and #3. Adjust if out of specification.

IN EX

8. Turn the flywheel magnet clockwise and align the “TDC” mark on the flywheel magnet with the pointer, and check that the “” marks on the driven sprockets are aligned.

9. Loosen the tensioner bolt 7, and then remove the spring 8, timing belt 9, driven sprockets 0, camshaft caps A, and camshafts B.

S6D85170

NOTE:

• Check the valve clearance when the engine is cold.

• Note the measurement.

5-11

S6D85180

NOTE:

Do not mix the valve train parts. Keep them organized in their proper groups.

10. Remove the valve lifters from the cylinder head.

6D81G11

Power unit

11. Remove the valve shim C from the valve lifter D using a thin screwdriver.

S6D85190

12. Measure the valve shim thickness with a micrometer, and then note the measurement.

13. Select the necessary valve shim by calculating its thickness with the following formula.

Necessary valve shim thickness = Removed valve shim thickness + Measured valve clearance – Specified valve clearance

Example: If the “Removed valve shim thickness” is 2.10 mm, the “Measured valve clearance” is 0.30 mm and the “Specified valve clearance” is

0.20 mm, then the necessary valve shim

thickness = 2.10 + 0.30 – 0.20 = 2.20 mm

19. Check that the “TDC” mark a on the flywheel magnet is aligned with the pointer

, and that “” marks c and d on the

driven sprockets are aligned.

20. Install the timing belt.

21. Install the spark plugs, and then connect the spark plug wires, fuel hoses, and blowby hose.

Spark plug:

25 N·m (2.5 kgf·m, 18.4 ft·lb)

S6D85200

1 2 3 4 5 6

14. Install the necessary valve shim into the valve lifter, and then install the valve lifters into the cylinder head.

15. Install the camshafts, camshaft caps, driven sprockets, and timing belt, and then tighten the tensioner bolt.

16. Check the valve clearance. Adjust if necessary.

17. Loosen the tensioner bolt, and then remove the timing belt and driven sprockets.

18. Install the cylinder head cover and driven sprockets.

6D81G11

22. Install the spark plug wire cover, filter, and flywheel magnet cover.

Spark plug wire cover screw:

4 N·m (0.4 kgf·m, 3.0 ft·lb)

5-12

7 8 9

POWR

Power unit

Replacing the timing belt

CAUTION:

• Do not turn the drive sprocket counterclockwise, otherwise the valve system may be damaged.

• Do not remove the ignition timing pointer.

• Do not turn the drive sprocket or the driven sprockets when the timing belt is not installed. Otherwise the piston and valves will interfere with each other and be damaged.

1. Remove the flywheel magnet cover.

2. Loosen the flywheel magnet nut.

CAUTION:

To prevent damage to the engine or tools, screw in the puller set bolts evenly and completely so that the 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.

CAUTION:

Apply force in the direction of the arrows shown to prevent the flywheel holder from slipping off easily.

Flywheel magnet holder: YB-06139

3. Remove the flywheel magnet.

Universal puller: YB-06117

4. Remove the Woodruff key 1 and stator assembly 2.

S6D85210

NOTE:

Do not loosen the pulser coil screw.

5. Turn the drive sprocket clockwise and align the hole a on the retaining plate with the projection b on the cylinder block, and check that “” marks c and

on the driven sprockets are aligned.

5-13

6D81G11

Power unit

9. Check that “” marks c and d on the driven sprockets are aligned.

S6D85220

6. Disconnect the cooling water hose and remove the bracket 4.

7. Remove the spring 5 and timing belt tensioner 6, and then remove the timing belt 7 from the driven sprockets, then from the drive sprocket.

1 2

S6D85240

4 5

8. Check that the hole a on the retaining plate and the projection b on the cylinder block are aligned.

S6D85230

6 7 8 9

6D81G11

5-14

POWR

Power unit

10. Install a new timing belt 8 onto the drive sprocket with its part number in the upright position, and then install the belt onto the driven sprockets by turning it counterclockwise.

67F-46241-00

S6D85290

13. Install the spring A.

S6D85260

14. Take up the timing belt slack by turning the drive sprocket clockwise at least two full turns.

15. Tighten the timing belt tensioner bolt to the specified torque.

S6D85250

CAUTION:

• Do not twist, turn inside out, or bend the timing belt beyond the maximum limit of 25 mm (1.0 in) otherwise it can be damaged.

• Do not get oil or grease on the timing belt.

NOTE:

The lower edge of the timing belt should be 2 mm (0.08 in) e from the bottom of the driven sprockets.

Timing belt tensioner bolt:

39 N·m (3.9 kgf·m, 28.8 ft·lb)

16. Turn the drive sprocket two full turns, and then check that the alignment marks are aligned.

11. Install the timing belt tensioner 9 and finger tighten the bolt 0 until the bolt seat contacts the timing belt tensioner.

12. Loosen the timing belt tensioner bolt 90°.

17. Install the bracket and connect the cool-

S6D85280

ing water hose.

5-15

6D81G11

Power unit

18. Install the stator assembly and Woodruff key.

19. Install the flywheel magnet.

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.

4. Disconnect the throttle cable and shift cable.

5. Disconnect the fuel hose and shift position switch coupler.

6. Disconnect the cooling water pilot hose, canister hose, and flushing hose.

7. Remove the oil dipstick.

8. Remove the apron 1, and then remove the power unit by removing the bolts 2.

3 4

Flywheel magnet holder: YB-06139

Flywheel magnet nut:

215 N·m (21.5 kgf·m, 158.6 ft·lb)

20. Install the flywheel magnet cover.

Removing the power unit

NOTE:

It is recommended to loosen the flywheel magnet nut before removing the power unit to improve working efficiency.

1. Remove the flywheel magnet cover.

2. Disconnect the battery leads and trim sensor coupler.

3. Remove the junction box cover, and then disconnect the PTT motor leads and PTT switch coupler.

9. Remove the flywheel magnet.

S6D85350

5 6 7 8 9

6D81G11

5-16

POWR

Power unit

Removing the timing belt and sprockets

CAUTION:

• Do not turn the drive sprocket counter-

clockwise, otherwise the valve system may be damaged.

• Do not turn the drive sprocket or the

driven sprockets when the timing belt is not installed. Otherwise the piston and valves will interfere with each other and be damaged.

1. Turn the drive sprocket clockwise and align the hole a on the retaining plate with the projection b on the cylinder block, and check that “” marks c and

on the driven sprockets are aligned.

NOTE:

• Use a deep socket 2 for this procedure.

• Do not turn the camshaft when loosening

the drive sprocket nut.

Crankshaft holder

3: YB-06552

3. Disconnect the cooling water hose and remove the bracket.

4. Remove the spring and timing belt tensioner, and then remove the timing belt from the driven sprockets, then from the drive sprocket.

5. Loosen the driven sprocket bolts 4, and then remove the driven sprockets 5.

2. Loosen the drive sprocket nut 1.

S6D85220

S6D85370

NOTE:

Do not turn the camshafts when loosening the driven sprocket bolts.

Flywheel magnet holder: YB-06139

6. Remove the nut 1, drive sprocket 6, retaining plate 7, and Woodruff key 8.

5-17

S6D85360

6D81G11

Power unit

S6D85380

Checking the timing belt and sprockets

1. Check the interior and exterior of the timing belt for cracks, damage, or wear. Replace if necessary.

S6D85390

NOTE:

• Apply engine oil to the driven sprocket bolts before installation.

• Do not turn the camshafts when tightening the driven sprocket bolts.

Flywheel magnet holder: YB-06139

Driven sprocket bolt 2:

60 N·m (6.0 kgf·m, 44.3 ft·lb)

1 2 3 4

2. Check the drive sprocket and driven sprockets for cracks, damage, or wear. Replace if necessary.

Installing the sprockets and timing belt

1. Install the dowels and driven sprockets

, and check that “” marks a and

on the driven sprockets are aligned.

2. Tighten the driven sprocket bolts 2 to the specified torque.

S6D85660

5 6 7 8 9

6D81G11

5-18

POWR

Power unit

3. Install the retaining plate 3, Woodruff key 4, drive sprocket 5, and nut 6, and then tighten the nut.

S60C5240

NOTE:

• Apply engine oil to the drive sprocket nut

before installation.

• Tighten the drive sprocket nut finger tight.

6. Tighten the drive sprocket nut 6 to the specified torque.

S6D85410

NOTE:

Use a deep socket 7 for this procedure.

Crankshaft holder

8: YB-06552

Drive sprocket nut 6:

265 N·m (26.5 kgf·m, 195.5 ft·lb)

4. Check that the hole c on the retaining plate is aligned with the projection d on the cylinder block.

S6D85300

5. Install the timing belt and timing belt tensioner.

NOTE:

For timing belt installation procedure, see “Replacing the timing belt.”

5-19

6D81G11

Power unit / Throttle link

Throttle link

3 4

No. Part name Q’ty Remarks

1 Throttle cam 1 2Bolt 1 M6 × 35 mm 3 Collar 1 4 Wave washer 2 5 Washer 2 6Spring 1 7 Washer 2 8 Throttle lever 1

9Bolt 1 M6 × 25 mm 10 Collar 1 11 Throttle link rod 1 12 Nut 1 13 Throttle link rod joint 1 14 Bracket 1 15 Bolt 2 M6 × 30 mm

S6D84140

6 7 8 9

6D81G11

5-20

POWR

Power unit

ECM

No. Part name Q’ty Remarks

1 Wiring harness 1

2Bracket 1

3Bolt 2 M6 × 15 mm

4Bolt 2 M6 × 12 mm

5Bracket 1

6Bracket 1

7Bracket 1

8Bolt 2 M6 × 20 mm

9 Collar 4 10 Grommet 4 11 Bolt 4 M6 × 30 mm 12 ECM 1 13 Rectifier Regulator 1 14 Bolt 2 M6 × 25 mm 15 Bolt 2 M6 × 20 mm 16 Bracket 1 17 Bolt 5 M6 × 30 mm

S6D85050

5-21

6D81G11

ECM / Junction box

Junction box

3 N

m (0.3 kgf

m, 2.2 ft

Ib)

4 N

m (0.4 kgf

m, 3.0 ft

Ib)

4 N

m (0.4 kgf

No. Part name Q’ty Remarks

1Screw 1 ø6 × 25 mm

2 Main and fuel pump relay 1

3 Power trim and tilt relay 1

4 Washer 2

5Nut 2

6Cap 2

7Bolt 2 M6 × 20 mm

8 Ground lead 1

9Fuse 1 30 A 10 Fuse 3 20 A 11 Cap 1 12 Cap 3 13 Starter relay 1 14 Holder 1 15 Screw 1 ø6 × 20 mm 16 Bolt 1 M6 × 10 mm 17 Cap 1

m, 3.0 ft

4 N

Ib)

m (0.4 kgf

m, 3.0 ft

Ib)

S6D85060

5 6 7 8 9

6D81G11

5-22

POWR

Power unit

3 N

m (0.3 kgf

4 N

m (0.4 kgf

m, 2.2 ft

Ib)

m, 3.0 ft

4 N

Ib)

m (0.4 kgf

m, 3.0 ft

Ib)

4 N

m (0.4 kgf

m, 3.0 ft

Ib)

S6D85060

No. Part name Q’ty Remarks

18 Holder 1 19 Junction box 1 20 Collar 5 21 Grommet 5 22 Bolt 2 M6 × 10 mm 23 Clamp 1 24 Grommet 1

5-23

6D81G11

Junction box / Cylinder head

Cylinder head

Not reusable

1 14 N

2 28 N

1 15 N

2 30 N

3 90˚

25 N

No. Part name Q’ty Remarks

1 Cylinder head 1

2 Exhaust valve 8

3 Intake valve 8

4Gasket 1

5 Collar 2

6Bolt 5 M8 × 55 mm

7Bolt 2 M6 × 25 mm

8 Cover 1

9 Thermostat 1 10 Bolt 10 M10 × 143 mm 11 Spark plug 4 12 Bolt 2 M8 × 40 mm 13 Bolt 2 M6 × 22 mm 14 Anode cover 2 15 Anode 2 16 Grommet 2 17 Valve shim 16

•

m (1.5 kgf • m, 11.1 ft

•

m (3.0 kgf • m, 22.1 ft

•

m (2.5 kgf • m, 18.4 ft

271

•

Ib)

•

lb) lb)

m (1.4 kgf m (2.8 kgf

m, 10.3 ft

m, 20.7 ft

lb)

S6D85080

1 2 3 4 5 6 7 8 9

6D81G11

5-24

POWR

Power unit

1 15 N

2 30 N

3 90˚

25 N

•

m (1.5 kgf • m, 11.1 ft

•

m (3.0 kgf • m, 22.1 ft

•

m (2.5 kgf • m, 18.4 ft

271

•

lb) lb)

•

Ib)

1 14 N

2 28 N

m (1.4 kgf

m (2.8 kgf

m, 10.3 ft

m, 20.7 ft

lb)

S6D85080

No. Part name Q’ty Remarks

18 Valve lifter 16 19 Valve cotter 32 20 Valve spring retainer 16 21 Valve spring 16 22 Valve spring seat 16 23 Valve seal 16 24 Valve guide 16

Not reusable

5-25

6D81G11

Cylinder head

Removing the cylinder head

1. Remove the cylinder head cover.

2. Remove camshaft caps 1 and 2 in the sequence shown.

3. Remove the camshaft (intake) 3, camshaft (exhaust) 4, and oil seals 5.

S6D85420

NOTE:

Do not mix the valve train parts. Keep them organized in their proper groups.

5. Remove the cylinder head bolts in the sequence shown.

S6D85440

1 2 3 4

S6D85430

4. Remove the valve shims 6 from the valve lifters 7.

CAUTION:

Do not scratch or damage the mating surfaces of the cylinder head and cylinder block.

5 6 7 8

6D81G11

S60C5380

5-26

POWR

Power unit

6. Remove the intake and exhaust valves.

Valve spring free length a:

53.20 mm (2.0945 in)

2. Measure the valve spring tilt b. Replace if above specification.

Valve spring tilt limit b:

2.6 mm (0.10 in)

NOTE:

Be sure to keep the valves, springs, and other parts in the order as they were removed.

Valve spring compressor 8:

YM-01253

Valve spring compressor attachment

YB-06320

Checking the valve lifters

1. Check the valve lifters for damage, scratches, or wear. Replace if necessary.

Checking the valve springs

1. Measure the valve spring free length a. Replace if below specification.

Checking the valves

1. Check the valve face for pitting or wear. Replace if necessary.

2. Measure the valve margin thickness a. Replace if out of specification.

Valve margin thickness a:

Intake:

0.80–1.20 mm (0.0315–0.0472 in)

Exhaust:

1.00–1.40 mm (0.0394–0.0551 in)

5-27

3. Measure the valve stem diameter b. Replace if out of specification.

6D81G11

Cylinder head

Valve stem diameter b:

Intake:

5.975–5.990 mm (0.2352–0.2358 in)

Exhaust:

5.960–5.975 mm (0.2346–0.2352 in)

4. Measure the valve stem runout. Replace if above specification.

S60C5450

Valve guide inside diameter a:

Intake and exhaust:

6.000–6.018 mm (0.2362–0.2369 in)

2. Calculate the valve stem-to-valve guide clearance as follows. Replace the valve guide if out of specification.

Valve stem-to-valve guide clearance = valve guide inside diameter – valve stem diameter:

Intake:

0.010–0.043 mm (0.0004–0.0017 in)

Exhaust:

0.025–0.058 mm (0.0010–0.0023 in)

1 2 3 4 5

Valve stem runout limit:

0.01 mm (0.0004 in)

Checking the valve guides

NOTE:

Before checking the valve guide make sure that the valve stem diameter is within specification.

1. Measure the valve guide inside diameter

Replacing the valve guides

1. Remove the valve guide 1 by striking the special service tool from the combustion chamber side.

7 8 9

Valve guide remover/installer:

YM-04064-A

6D81G11

5-28

POWR

Power unit

2. Install the new valve guide 2 by striking the special tool from the camshaft side to the specified position a.

NOTE:

• Before installing the valve guide, mark its

installation position b as shown.

• Apply engine oil to the surface of the new

valve guide.

Valve guide remover/installer:

YM-04064-A

4. Measure the valve guide inside diameter.

Valve guide inside diameter:

Intake and exhaust:

6.000–6.018 mm (0.2362–0.2369 in)

Checking the valve seat

1. Eliminate carbon deposits from the valve with a scraper.

2. Apply a thin, even layer of Mechanic’s blueing dye (Dykem) onto the valve seat.

3. Lap the valve slowly on the valve seat with a valve lapper (commercially available) as shown.

Valve guide position a:

11.5 ± 0.2 mm (0.45 ± 0.01 in)

3. Insert the special service tool into the valve guide 2, and then ream the valve guide.

NOTE:

• Turn the valve guide reamer clockwise to

ream the valve guide.

• Do not turn the reamer counterclockwise

when removing the reamer.

4. Measure the valve seat contact width where the blueing dye is adhered to the valve face. Reface the valve seat if the valve is not seated properly or if the valve seat contact width is out of specification. Replace the valve guide if the valve seat contact is uneven.

5-29

Valve guide reamer: YM-04066

6D81G11

Valve seat contact width a:

1.20–1.60 mm (0.0472–0.0630 in)

Cylinder head

Slag or rough surface

CAUTION:

Do not over cut the valve seat. Be sure to turn the cutter evenly downward at a pressure of 40–50 N (4–5 kgf, 8.8–11 lbf) to prevent chatter marks.

1 2 3

Refacing the valve seat

1. Reface the valve seat with the valve seat cutters.

30˚

Neway valve seat kit: YB-91044

2. Cut the surface of the valve seat with a 45° cutter by turning the cutter clockwise until the valve seat face has become smooth.

45˚

30˚

60˚

45˚

S69J5845

3. Use a 30° cutter to adjust the contact width of the top edge of the valve seat.

30˚

S69J5880

Previous contact width

4. Use a 60° cutter to adjust the contact width of the bottom edge of the valve seat.

4 5 6 7

6D81G11

S63P5230

Previous contact width

60˚

S69J5890

5-30

8 9

POWR

Power unit

5. Use a 45° cutter to adjust the contact width of the valve seat to specification.

45˚

S69J5900

Previous contact width

Specified contact width

6. If the valve seat contact area is too wide and situated in the center of the valve face, use a 30° cutter to cut the top edge of the valve seat, a 60° cutter to cut the bottom edge to center the area and set its width.

8. If the valve seat contact area is too narrow and situated near the bottom edge of the valve face, use a 60° cutter to cut the bottom edge of the valve seat. If necessary, use a 45° cutter to center the area and set its width.

Previous contact width

9. Apply a thin, even layer of lapping compound onto the valve seat, and then lap the valve using a valve lapper (commercially available).

Previous contact width

7. If the valve seat contact area is too narrow and situated near the top edge of the valve face, use a 30° cutter to cut the top edge of the valve seat. If necessary, use a 45° cutter to center the area and set its width.

Previous contact width

5-31

CAUTION:

Do not get the lapping compound on the valve stem and valve guide.

10. After every lapping procedure, be sure to clean off any remaining lapping compound from the cylinder head and the valve.

11. Check the valve seat contact area of the valve again.

Checking the camshafts

1. Measure the cam lobe. Replace if out of specification.

6D81G11

Cam lobe a:

Intake:

36.48–36.58 mm (1.4362–1.4402 in)

Exhaust:

36.90–37.06 mm (1.4528–1.4591 in)

Cam lobe b:

Intake:

29.95–30.05 mm (1.1791–1.1831 in)

Exhaust:

29.92–30.08 mm (1.1780–1.1842 in)

2. Measure the camshaft runout. Replace if above specification.

Cylinder head

S69J5970

Camshaft journal diameter c:

24.960–24.980 mm (0.9827–0.9835 in)

Camshaft cap inside diameter d:

25.000–25.021 mm (0.9843–0.9851 in)

Checking the cylinder head

1. Eliminate carbon deposits from the combustion chambers and check for deterioration.

2. Check the cylinder head warpage using a straightedge 1 and thickness gauge in the directions shown. Replace if above specification.

1 2 3 4 5

S6D85450

Camshaft runout limit:

0.03 mm (0.0012 in)

3. Measure the camshaft journal diameter

and cylinder head journal inside diameter d. Replace the camshaft and cylinder head if out of specification.

S6D85470

8 9

S6D85460

Cylinder head warpage limit:

0.1 mm (0.0039 in)

6D81G11

5-32

POWR

Power unit

Installing the valves

1. Install a new valve seal 1 onto the valve guide.

S60C5660

2. Install the valve 2, valve spring seat 3, valve spring 4, and valve spring retainer

in the sequence shown, and then

attach the special service tools.

3. Compress the valve spring, and then install the valve cotters 8 using a thin screwdriver with a small amount of grease applied to it.

NOTE:

The valve spring can be installed in any direction.

Valve spring compressor 6:

YM-01253

Valve spring compressor attachment

YB-06320

S60C5680

4. Lightly tap the valve spring retainer with a plastic hammer to set the valve cotters securely.

S60C5690

Installing the cylinder head

1. Check that the piston of cylinder #1 is at TDC.

2. Install a new gasket and the cylinder head, and then tighten the bolts to the specified torques in the sequence shown.

5-33

6D81G11

Cylinder head

NOTE:

• Apply engine oil to the valve shims and

valve lifters before installation.

• Install the valve shims and valve lifters in

their original positions.

4. Install the camshaft (intake) 1 and camshaft (exhaust) 2 with the new oil seals

1 2

90˚

CAUTION:

Do not reuse the cylinder head gasket, always replace it with a new one.

NOTE:

• Apply engine oil to the cylinder head bolts before installation.

• Tighten the M10 bolts to the specified torques in two stages first, and then tighten the M8 bolts to 14 N·m (1.4 kgf·m, 10.3 ft·lb).

• Make a mark a on the M10 bolts and the cylinder head, and then tighten the bolts 90° from the mark.

• Tighten the M8 bolts to 28 N·m (2.8 kgf·m,

20.7 ft·lb).

Cylinder head bolt (M10):

1st: 15 N·m (1.5 kgf·m, 11.1 ft·lb) 2nd: 30 N·m (3.0 kgf·m, 22.1 ft·lb) 3rd: 90°

Cylinder head bolt (M8):

1st: 14 N·m (1.4 kgf·m, 10.3 ft·lb) 2nd: 28 N·m (2.8 kgf·m, 20.7 ft·lb)

S6D85480

NOTE:

• Apply molybdenum disulfide grease to the cam lobes.

• Be sure to install the camshaft with the fuel pump drive cam b on the intake side.

5. Check that the camshaft dowel holes

are in the position shown in the illustration. Adjust if necessary.

S1280B

S6D85490

3 4 5 6 7 8 9

3. Install the valve shims and valve lifters.

6D81G11

S6D85500

5-34

Yamaha F90HP User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Important information

Contents

How to use this manual

Safety while working

Identification

Predelivery checks

General specifications

Tightening torques

Periodic checks and adjustments

Special service tools

Maintenance interval chart

Top cowling

Fuel system

Power unit

Control system

Bracket unit

Lower unit

General

Fuel system

Special service tools

Hose routing

Fuel filter and fuel pump

Intake manifold

Vapor separator

Canister

Power unit

Special service tools

Power unit

Throttle link

Junction box

Cylinder head