Yamaha Z300A Manual

Z300A
LZ300A
SUPPLEMENTARY
SERVICE MANUAL
292211 6D0-28197-3F-1X

NOTICE
This Supplementary Service Manual has been prepared to introduce new service and new data
information for the Z300 and LZ300 which are based on the Z250 and LZ250. For complete informa-
tion on service procedures, it is necessary to use this Supplementary Service Manual together with
the following manual.
Important information 1
Particularly important information is distinguished in this manual by the following notations:
The Safety Alert Symbol means ATTENTION! BECOME ALERT! YOUR SAFETY IS
INVOLVED!
WARNING
Failure to follow WARNING instructions could result in severe injury or death to the machine
operator, a bystander, or a person inspecting or repairing the outboard motor.
CAUTION:
A CAUTION indicates special precautions that must be taken to avoid damage to the out-
board motor.
NOTE:
A NOTE provides key information to make procedures easier or clearer.
CAUTION:
USE UNLEADED STRAIGHT GASOLINE ONLY
• Gasoline containing lead can cause performance loss and engine damage.
• Do not use gasoline mixed with oil during the break-in period or anytime thereafter.
YAMALUBE 2-STROKE OUTBOARD OIL IS RECOMMENDED.
Z250D, LZ250D SERVICE MANUAL: 60V-28197-3E-11
Z300A, LZ300A
SUPPLEMENTARY SERVICE MANUAL
©2003 by Yamaha Motor Co., Ltd.
1st Edition, July 2003
All rights reserved.
Any reprinting or unauthorized use
without the written permission of
Yamaha Motor Co., Ltd.
is expressly prohibited.
Printed in the Netherlands

Contents
General information 1
GEN
INFO
Specifications 2
SPEC
Periodic checks and adjustments 3
CHK
ADJ
Fuel system 4
FUEL
Power unit 5
POWR
Lower unit 6
LOWR
Bracket unit 7
BRKT
Electrical systems 8
ELEC
Troubleshooting 9
TRBL
SHTG
Index
–+

6D03F1X
General information
How to use this manual.................................................................................... 1
Manual format............................................................................................... 1
Symbols........................................................................................................ 2
Identification...................................................................................................... 3
Applicable models ........................................................................................ 3
Serial number ............................................................................................... 3
Features and benefits....................................................................................... 4
Crankcase and cylinders .............................................................................. 4
Intake system ............................................................................................... 6
Upper case ................................................................................................... 8
Lower case ................................................................................................... 9
ECM (Electronic Control Module) ............................................................... 10
Wiring harness connector holder................................................................ 10
Propeller selection .......................................................................................... 11
Propeller size.............................................................................................. 11
Selection..................................................................................................... 11
Predelivery checks ......................................................................................... 12
Checking the fuel system ........................................................................... 12
Checking the gear oil level ......................................................................... 12
Checking the engine oil level...................................................................... 12
Checking the battery................................................................................... 12
Checking the outboard motor mounting height........................................... 13
Checking the remote control cables ........................................................... 13
Checking the steering system .................................................................... 14
Checking the gear shift and throttle operation............................................ 14
Checking the power trim and tilt system..................................................... 14
Checking the engine start switch and engine stop lanyard switch ............. 14
Checking the cooling water pilot hole ......................................................... 15
Test run ...................................................................................................... 15
Break-in ...................................................................................................... 15
After test run ............................................................................................... 15

6D03F1X
Specifications
General specifications.................................................................................... 16
Maintenance specifications ........................................................................... 18
Power unit................................................................................................... 18
Lower unit ................................................................................................... 20
Electrical ..................................................................................................... 20
Dimensions................................................................................................. 23
Tightening torques.......................................................................................... 25
Specified torques........................................................................................ 25
General torques.......................................................................................... 27
Periodic checks and adjustments
Special service tools ...................................................................................... 28
Maintenance interval chart............................................................................. 31
Oil injection system ........................................................................................ 32
Adjusting the oil pump link rod.................................................................... 32
Lower unit ........................................................................................................ 32
Checking the lower unit for air leakage ...................................................... 32
General............................................................................................................. 33
Lubricating the outboard motor................................................................... 33
Fuel system
Fuel filter .......................................................................................................... 35

6D03F1X
Power unit
Power unit........................................................................................................ 36
Removing the power unit............................................................................ 37
Crankcase........................................................................................................ 39
Removing the crankcase covers ................................................................ 40
Installing the crankcase covers .................................................................. 40
Installing the power unit.............................................................................. 40
Lower unit
Propeller shaft housing (regular rotation model) ........................................ 43
Shimming (regular rotation model) ............................................................... 45
Selecting the pinion shims.......................................................................... 46
Backlash (regular rotation model)................................................................. 47
Measuring the forward and reverse gear backlash .................................... 47
Propeller shaft housing (counter rotation model) ....................................... 50
Drive shaft and lower case (counter rotation model) .................................. 52
Disassembling the reverse gear ................................................................. 54
Assembling the lower case......................................................................... 54
Shimming (counter rotation model) .............................................................. 56
Selecting the pinion shims.......................................................................... 57
Backlash (counter rotation model)................................................................ 58
Measuring the forward and reverse gear backlash .................................... 58
Bracket unit
Bottom cowling ............................................................................................... 61
Upper case, steering arm, swivel bracket, and clamp brackets................. 64
Power trim and tilt unit ................................................................................... 69
Checking the hydraulic pressure ................................................................ 69

6D03F1X
Electrical systems
Electrical components.................................................................................... 72
Port view..................................................................................................... 72
Top view ..................................................................................................... 73
Troubleshooting
Self-diagnosis.................................................................................................. 74
Diagnosing the electronic control system ................................................... 74
Wiring diagram

GEN
INFO General information
16D03F1X
How to use this manual 1
Only chapters containing revisions or additional items in the base manual have been included in this
manual.
All special service tools introduced in this manual are mentioned in Chapter 3.
Manual format
The format of this manual has been designed to make service procedures clear and easy to under-
stand. Use the information below as a guide for effective and quality service.
1Parts are shown and detailed in an exploded diagram and are listed in the components list.
2Tightening torque specifications are provided in the exploded diagrams and after a numbered
step with tightening instructions.
3Symbols are used to indicate important aspects of a procedure, such as the grade of lubricant
and lubrication point.
4The components list consists of part names and part quantities, as well as bolt and screw dimen-
sions.
5Service points regarding removal, checking, and installation are shown in individual illustrations
to explain the relevant procedure.
LOWR Lower unit
6-5 62Y5A11
Lower unit
No. Part name Q’ty Remarks
1 Lower unit 1
2 Plastic tie 1 Not reusable
3Hose 1
4 Check screw 1
5 Gasket 2 Not reusable
6 Dowel pin 2
7 Bolt 4 M10 40 mm
8 Drain screw 1
9Grommet 1
10 Bolt 1 M10 45 mm
11 Bolt 1 M8 60 mm
12 Thrust washer 1
13 Propeller 1
14 Washer 1
15 Washer 1
16 Cotter pin 1 Not reusable
17 Propeller nut 1
18 Trim tab 1
LOWR Lower unit
6-19 62Y5A11
Removing the drive shaft
1. Remove the drive shaft assembly and
pinion, and then pull out the forward
gear.
Disassembling the drive shaft
1. Install the pinion nut 1, tighten it finger
tight, and then remove the drive shaft
bearing 2using a press.
CAUTION:
•Do not press the drive shaft threads a
directly.
•Do not reuse the bearing, always
replace it with a new one.
Disassembling the forward gear
1. Remove the taper roller bearing from the
forward gear using a press.
CAUTION:
Do not reuse the bearing, always replace
it with a new one.
2. Remove the needle bearing from the for-
ward gear.
CAUTION:
Do not reuse the bearing, always replace
it with a new one.
Drive shaft holder 4 1: 90890-06518
Pinion nut holder 2: 90890-06505
Socket adapter 2 3: 90890-06507
Bearing inner race attachment 3:
90890-06639
S62Y6850K
Bearing separator 1: 90890-06534
Stopper guide plate 2: 90890-06501
Stopper guide stand 3:
90890-06538
Bearing puller 4: 90890-06535
Bearing puller claw 1 5:
90890-06536
S62Y6740K
5
4
321

6D03F1X 2
Symbols
The symbols below are designed to indicate the content of a chapter.
General information
Specifications
Periodic checks and adjustments
Fuel system
Power unit
Lower unit
Bracket unit
Electrical systems
Troubleshooting
GEN
INFO
SPEC
CHK
ADJ
FUEL
POWR
LOWR
BRKT
ELEC
TRBL
SHTG
–+
Symbols 1to 6indicate specific data.
1Special tool
2Specified oil or fluid
3Specified engine speed
4Specified tightening torque
5Specified measurement
6Specified electrical value
(resistance, voltage, electric current)
Symbols 7to Cin an exploded diagram indicate the grade of lubricant and the lubrication point.
7Apply 2-stroke outboard motor oil
8Apply gear oil
9Apply water resistant grease (Yamaha grease A)
0Apply molybdenum disulfide grease
AApply corrosion resistant grease
(Yamaha grease D)
BApply low temperature resistant grease
(Yamaha grease C)
CApply injector grease
Symbols Dto Iin an exploded diagram indicate the type of sealant or locking agent and the appli-
cation point.
DApply Gasket Maker
EApply Yamabond No. 4
FApply LOCTITE 271 (red)
GApply LOCTITE 242 (blue)
HApply LOCTITE 572
IApply silicon sealant
123456
T
R
.
.
7890ABC
E G
A M
D
C I
DEFGHI
GM
4
271
LT
242
LT
572
LT SS
How to use this manual
1
2
3
4
5
6
7
8
9

GEN
INFO General information
36D03F1X
Identification 1
Applicable models
This manual covers the following models.
Serial number
The outboard motor serial number is
stamped on a label attached to the port
clamp bracket.
1Model name
2Approved model code
3Transom height
4Serial number
Applicable models
Z300AETO, LZ300AETO
Model name Approved
model code
Starting
serial No.
Z300AETO 6D0 X: 1000001–
U: 1000001–
LZ300AETO 6D1 X: 1000001–

6D03F1X 4
Features and benefits 1
Crankcase and cylinders
The following modifications have been adopted to increase the output as compared to the Z250
power unit.
•The material of the crankshaft has been changed to a high-grade clean steel(*1) to increase dura-
bility against stress.
•Wider exhaust ports with planed-off edges have been adopted and the exhaust timing has been
changed to reduce the exchange loss of the exhaust gas.
•Cooling water jackets have been incorporated to the crankcase to increase engine-cooling ability.
*1: Steel with decreased nonmetallic inclusion content
1Crankshaft identification
Identification mark: 2 mm (0.079 in) punch mark
2Exhaust port
3Crankcase water jackets
ÈWater flow
Identification / Features and benefits

GEN
INFO General information
56D03F1X
•Newly-forged lightweight pistons with a hard anodic coating on the piston pin boss have been
adopted to increase durability and reduce the inertia mass of the pistons.
•The top piston rings are made of steel and are ion-plated to increase durability.
•The heat treatments for the piston pins and connecting rods have been changed so that there is
multiphase carbonization to increase durability.
1Ion plating (chromium)
2Identification mark: R
3Identification mark: 6D0
4Oil groove
5Hard anodic coating
6Identification mark
ÈTop ring
ÉSecond ring

6D03F1X 6
•The anti-corrosion anodes in the cooling water passages of the cylinder block are larger to
increase reliability and performance.
1Anodes
Intake system
The openings in the throttle bodies were enlarged to a 46 mm (1.81 in) diameter to increase power
output.
Features and benefits

GEN
INFO General information
76D03F1X
An oil groove has been added to each reed valve seat. Oil in the groove helps to reduce impact
when the reed valve contacts the reed valve seat.
The dimensions of the reed valve assembly are the same as those for the Z250.
1Oil groove
2Identification mark: 6D0
The oil pump has been newly designed to obtain optimal oil supply.
ÈModel
ÉIdentification mark

6D03F1X 8
Upper case
Water jackets have been incorporated to both sides of the lower part of the upper case. This struc-
ture reduces the heat transfer to the upper case from the exhaust gas.
The cooling water discharged from the water pump is supplied to the upper case around the muffler
from the pipe connected to the exhaust guide, flows down into the water jacket, and then drains to
the lower case.
Water jackets have been incorporated to the exhaust manifold to protect it from the high-tempera-
ture exhaust gas.
Fresh cooling water from the water pump accumulates in the water jacket, and then drains into the
muffler.
1Muffler
2Upper case
3Gasket
4Upper case water jacket
5Lower case
6Exhaust guide
7Hose
8Exhaust manifold
9Water
0Water pump
ÈWater flow
ÉExhaust passage
Features and benefits

GEN
INFO General information
96D03F1X
Lower case
The propeller shaft housing and the ring are newly designed to reduce the exhaust back-pressure
and cool the propeller damper.
Cooling water is taken in from the front of the trim tab, flows through the pipe in the lower case and
propeller shaft housing, and then is supplied directly to the propeller boss.
This prevents the cooling water from mixing with the exhaust gas in the exhaust passage in the
lower case and also prevents the cooling water from obstructing the exhaust gas.
Therefore, the exhaust back-pressure can be reduced.
A low gear ratio has been adopted to match the power output characteristics.
1Water pipe (for cooling the propeller boss)
2Heli-sert bushing
3Ring
4Fluorine-coated oil seals
5Propeller shaft housing (with water passage)
ÈWater flow
ÉPinion gear
ÊReduction gear
Ë
Ì
Í
Model Gear ratio
Z250 1.81
Z250F
Z300 1.75
Model Identification
mark Notes
Z300
LZ300 60X1 Same as Z250F
Model Identification
mark Notes
Z300 F 60X00 Same as Z250F
R 69L00 Same as 250C
LZ300 F 6D100 New
R 6D100 New

6D03F1X 10
ECM (Electronic Control Module)
ECMs have been adopted that are specific to each model to control the ignition and injection timing.
NOTE:
The diagnostic codes are the same as those for the Z250, and the latest version of the YDIS covers
all previous models with fuel injection.
ÈModel
ÉECM identification
ÊNote
ËFor Brazil
Wiring harness connector holder
A wiring harness connector holder has been added to the side of bottom cowling to secure the 10-
pin main harness, remote oil tank harness, warning indicator harness, and trim meter harness.
The wiring harness connector holder helps to organize the harnesses and hold them in place.
110-pin main harness
2Remote oil tank harness (Blue connector)
3Bottom cowling seal
4Holder
5Trim meter harness
6Warning indicator harness
7Isolator lead
S6D01100
ÈÉÊ
VZ225 (Z250H) 60Y-01
VZ250 (Z250F) 60X-01
Z250 (Z250D) 60V-01
60V-21 Ë
Z300 (Z300A) 6D0-00
Features and benefits

GEN
INFO General information
11 6D03F1X
Propeller selection 1
The performance of a boat and outboard
motor will be critically affected by the size
and type of propeller you choose. Propellers
greatly affect boat speed, acceleration,
engine life, fuel economy, and even boating
and steering capabilities. An incorrect choice
could adversely affect performance and
could also seriously damage the engine.
Use the following information as a guide for
selecting a propeller that meets the operating
conditions of the boat and the outboard
motor.
Propeller size
The size of the propeller is indicated on the
propeller boss end and on the side of the pro-
peller boss.
aPropeller diameter (in inches)
bPropeller pitch (in inches)
cPropeller type (propeller mark)
Selection
When the engine speed is at the full throttle
operating range (4,500–5,500 r/min), the
ideal propeller for the boat is one that pro-
vides maximum performance in relation to
boat speed and fuel consumption.
Regular rotation model
Counter rotation model
S69J1100
× -
abc
S60C1125
-
bc
Propeller size (in) Material
13 3/8 ×23 - M
Stainless
13 3/8 ×25 - M
13 3/4 ×17 - M2
13 3/4 ×19 - M2
13 3/4 ×21 - M
14 1/2 ×19 - T
14 1/2 ×21 - T
14 1/2 ×23 - M
14 3/4 ×25 - T
14 7/8 ×21 - M
15 ×17 - T
15 1/8 ×27 - T
15 1/4 ×15 - M
15 1/4 ×17 - M
15 1/4 ×19 - M
15 3/4 ×13 - M
Propeller size (in) Material
13 3/8 ×23 - ML
Stainless
13 3/4 ×17 - ML1
13 3/4 ×19 - ML1
13 3/4 ×21 - ML
14 1/2 ×19 - TL
14 1/2 ×21 - TL
15 ×17 - TL
15 1/4 ×15 - ML

6D03F1X 12
Predelivery checks 1
To make the delivery process smooth and
efficient, the predelivery checks should be
completed as explained below.
Checking the fuel system
1. Check that the fuel hoses are securely
connected and that the fuel tank is full
with fuel.
CAUTION:
•Use unleaded straight gasoline only.
•Do not use gasoline mixed with oil (pre-
mixed fuel).
Checking the gear oil level
1. Check the gear oil level.
Checking the engine oil level
1. Check that the engine oil level is
between the maximum and minimum
level marks.
Checking the battery
1. Check the capacity, electrolyte level, and
specified gravity of the battery.
2. Check that the positive and negative bat-
tery leads are securely connected.
Recommended engine oil:
YAMALUBE 2-stroke outboard
motor oil
Recommended battery capacity:
CCA/EN: 711 A
20HR/IEC: 100 Ah
Electrolyte specified gravity:
1.280 at 20 °C (68 °F)
S60V1290
S60V3260
Propeller selection / Predelivery checks

GEN
INFO General information
13 6D03F1X
Checking the outboard motor
mounting height
1. Check that the anti-cavitation plate is
aligned with the bottom of the boat. If the
mounting height is too high, cavitation
will occur and propulsion will be reduced.
Also, the engine speed will increase
abnormally and cause the engine to
overheat. If the mounting height is too
low, water resistance will increase and
reduce engine efficiency.
NOTE:
The optimum mounting height is affected by
the combination of the boat and the outboard
motor. To determine the optimum mounting
height, test run the outboard motor at differ-
ent 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 neu-
tral position and fully close the throttle
lever.
2. Check that the throttle cam 1is in its
fully closed position and align the center
of the throttle cam roller 2with the align-
ment mark a.
3. Check that the center of the set pin bis
aligned with the alignment mark con
the bottom cowling.
CAUTION:
The shift/throttle cable joint must be
screwed in a minimum of 8.0 mm (0.31 in)
d.
S60V1040
2
a
1
S60C1190
d