YAMAHA Z300A, LZ300A PARTS CATALOGUE

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 information on service procedures, it is necessary to use this Supplementary Service Manual together with the following manual.

Z250D, LZ250D SERVICE MANUAL: 60V-28197-3E-11

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.

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.

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

8

Electrical systems

– +

ELEC

Troubleshooting

9

TRBL

SHTG

Index

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

6D03F1X

GEN INFO

General information

How to use this manual

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 understand. Use the information below as a guide for effective and quality service.

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

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

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

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

5 Service points regarding removal, checking, and installation are shown in individual illustrations to explain the relevant procedure.

LOWR		Lower unit			3	2
Lower unit
No.	Part name		Q’ty		Remarks
1	Lower unit		1
2	Plastic tie		1	Not reusable
3	Hose		1
4	Check screw		1
5	Gasket		2	Not reusable
6	Dowel pin		2
7	Bolt		4	M10	40 mm
8	Drain screw		1
9	Grommet		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
6-5						62Y5A11
	4
						5

1

LOWR

Lower unit

Removing the drive shaft

1.Remove the drive shaft assembly and pinion, and then pull out the forward gear.

S62Y6850K

Drive shaft holder 4 1: 90890-06518 Pinion nut holder 2: 90890-06505 Socket adapter 2 3: 90890-06507

Disassembling the drive shaft

1.Install the pinion nut 1, tighten it finger tight, and then remove the drive shaft bearing 2 using a press.

CAUTION:

•Do not press the drive shaft threads a directly.

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

Bearing inner race attachment 3: 90890-06639

S62Y6740K

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

Disassembling the forward gear

1.Remove the taper roller bearing from the forward gear using a press.

6-19

62Y5A11

1

6D03F1X

How to use this manual

Symbols

The symbols below are designed to indicate the content of a chapter.

General information Fuel system Bracket unit

GEN			FUEL
INFO

Specifications			Power unit
SPEC			POWR

Periodic checks and adjustments Lower unit

	CHK	LOWR
	ADJ

Symbols 1 to 6 indicate specific data.

BRKT

Electrical systems

ELEC – +

Troubleshooting

TRBL

SHTG

1	2	3	4	5	6
				T
				.
				R
				.
1 Special tool			5 Specified measurement
2 Specified oil or fluid			6 Specified electrical value
3 Specified engine speed				(resistance, voltage, electric current)
4 Specified tightening torque

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

7

8

9

0

A

B

C

A

M

D

C

I

E

G

7 Apply 2-stroke outboard motor oil

A Apply corrosion resistant grease

8 Apply gear oil

(Yamaha grease D)

9 Apply water resistant grease (Yamaha grease A)

B Apply low temperature resistant grease

0 Apply molybdenum disulfide grease

(Yamaha grease C)

C Apply injector grease

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

D	E	F	G		H		I
GM	4	LT		LT		LT	SS
		271		242		572
D Apply Gasket Maker			G Apply LOCTITE 242 (blue)
E Apply Yamabond No. 4			H Apply LOCTITE 572
F Apply LOCTITE 271 (red)			I Apply silicon sealant

1

2

3

4

5

6

7

8

9

6D03F1X

2

GEN
INFO	General information

Identification

Applicable models

This manual covers the following models.

Applicable models

Z300AETO, LZ300AETO

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

	Model name	Approved	Starting
		model code	serial No.
	Z300AETO	6D0	X: 1000001–
			U: 1000001–
	LZ300AETO	6D1	X: 1000001–

3

6D03F1X

Identification / Features and benefits

Features and benefits

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 durability 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

È Water flow

6D03F1X

4

GEN INFO

General information

•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.

1 Ion plating (chromium)	È Top ring
2 Identification mark: R	É Second ring

3Identification mark: 6D0

4Oil groove

5Hard anodic coating

6Identification mark

5

6D03F1X

Features and benefits

•The anti-corrosion anodes in the cooling water passages of the cylinder block are larger to increase reliability and performance.

1 Anodes

Intake system

The openings in the throttle bodies were enlarged to a 46 mm (1.81 in) diameter to increase power output.

6D03F1X

6

GEN INFO

General information

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.

È Model

É Identification mark

7

6D03F1X

Features and benefits

Upper case

Water jackets have been incorporated to both sides of the lower part of the upper case. This structure 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.

1 Muffler	È Water flow
2 Upper case	É Exhaust passage

3Gasket

4Upper case water jacket

5Lower case

6Exhaust guide

7Hose

8Exhaust manifold

9Water

0 Water pump

6D03F1X

8

GEN
INFO	General information

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)

È Water flow É Pinion gear

Ê Reduction gear

Ë

Model		Gear ratio
Z250		1.81
Z250F		1.75
Z300
Ì
Model		Identification			Notes
		mark
Z300		60X1		Same as Z250F
LZ300
Í
Model		Identification			Notes
		mark
Z300	F	60X00		Same as Z250F
	R	69L00		Same as 250C
LZ300	F	6D100		New
	R	6D100		New

9

6D03F1X

Features and benefits

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.

			È		É	Ê
			VZ225 (Z250H)		60Y-01
			VZ250 (Z250F)		60X-01
			Z250 (Z250D)		60V-01
					60V-21	Ë
			Z300 (Z300A)		6D0-00
						S6D01100
È Model			Ê Note
É ECM identification			Ë For Brazil

Wiring harness connector holder

A wiring harness connector holder has been added to the side of bottom cowling to secure the 10pin 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

6D03F1X

10

GEN INFO

General information

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 and on the side of the propeller boss.

× - a b c

S69J1100

- b c

S60C1125

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 provides maximum performance in relation to boat speed and fuel consumption.

Regular rotation model

Propeller size (in)		Material
13 3/8 × 23 - M
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		Stainless
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
Counter rotation model
Propeller size (in)		Material
13 3/8 × 23 - ML
13 3/4 × 17 - ML1
13 3/4 × 19 - ML1
13 3/4 × 21 - ML		Stainless
14 1/2 × 19 - TL
14 1/2 × 21 - TL
15 × 17 - TL
15 1/4 × 15 - ML

11

6D03F1X

Propeller selection / Predelivery checks

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.

CAUTION:

•Use unleaded straight gasoline only.

•Do not use gasoline mixed with oil (premixed fuel).

Checking the gear oil level

1. Check the gear oil level.

S60V1290

Checking the engine oil level

1.Check that the engine oil level is between the maximum and minimum level marks.

S60V3260

Recommended engine oil: YAMALUBE 2-stroke outboard motor oil

Checking the battery

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

Recommended battery capacity: CCA/EN: 711 A

20HR/IEC: 100 Ah Electrolyte specified gravity:

1.280 at 20 °C (68 °F)

2.Check that the positive and negative battery leads are securely connected.

6D03F1X

12

GEN INFO

General information

Checking the outboard motor mounting height

1.Check that the anti-cavitation plate is aligned with the bottom of the boat. If the mounting height is too high, cavitation will occur and propulsion will be reduced. Also, the engine speed will increase abnormally and cause the engine to overheat. If the mounting height is too low, water resistance will increase and reduce engine efficiency.

NOTE:

The optimum mounting height is affected by the combination of the boat and the outboard motor. To determine the optimum mounting height, test run the outboard motor at different heights.

2

a

1

S60V1040

3.Check that the center of the set pin b is aligned with the alignment mark c on the bottom cowling.

2. Check that the clamp brackets are
secured with the clamp bolts.	d
	S60C1190

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 throttle cam 1 is in its fully closed position and align the center of the throttle cam roller 2 with the alignment mark a.

CAUTION:

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

13

6D03F1X

Predelivery checks

Checking the steering system

1.Check the steering friction for proper adjustment.

2.Check that the steering operates smoothly.

S60V1060

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 the fully closed position to the fully open position a.

N

F R

a

a

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.

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

3.Check that the engine turns off when the engine stop lanyard is pulled from the engine stop lanyard switch.

6D03F1X

14

GEN INFO

General information

Checking the cooling water pilot hole

1.Check that cooling water is discharged from the cooling water pilot hole.

S60V3140

Test run

1.Start the engine, and then check that the gear shift operates smoothly.

2.Check the engine idle speed after the engine has been warmed up.

3.Operate at trolling speed.

4.Run the outboard motor for 1 hour at 3,000 r/min or at half throttle, then for another hour at 4,000 r/min or at 3/4 throttle.

5.Check that the outboard motor does not tilt up when shifting into reverse and that water does not flow in over the transom.

NOTE:

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

Break-in

During the test run, perform the break-in operation in the following four stages.

1.First 10 minutes a of operation at idle

2.Fifty minutes b at 3,000 r/min or less

3.One hour c at 4,000 r/min or less

4.Eight hours d at 5,000 r/min or less with repeated wide-open-throttle operation for 5 minutes or less

a b	c	d
È 0 1	2	10

S60V1120

È Hour

After test run

1.Check for water in the gear oil.

2.Check for fuel leakage in the cowling.

3.Flush the cooling water passage with fresh water using the flushing kit and with the engine running at idle.

15

6D03F1X

Predelivery checks / General specifications

General specifications

Item	Unit		Model
		Z300AETO		LZ300AETO
Dimension
Overall length	mm (in)		868 (34.2)
Overall width	mm (in)		568 (22.4)
Overall height
(X)	mm (in)		1,830 (72.0)
(U)	mm (in)
		1,957 (77.0)		—
Boat transom height
(X)	mm (in)		635 (25.0)
(U)	mm (in)	762 (30.0)		—
Weight
(with stainless propeller)
(X)	kg (lb)		252 (556)
(U)	kg (lb)	257 (567)		—
Performance
Maximum output	kW (hp)	220.7 (300) at 5,000 r/min
Full throttle operating range	r/min	4,500–5,500
Maximum fuel consumption	L (US gal,	105.0 (27.7, 23.1) at 5,500 r/min
	lmp gal)/hr
Engine idle speed	r/min		700–760
Power unit
Type		2-stroke, 76°, V6, HPDI
Total displacement	cm3 (cu. in)	3,342 (203.9)
Bore × stroke	mm (in)	93.0 (3.66) × 82.0 (3.23)
Compression ratio			6.2
Control system		Remote control
Starting system		Electric starter
Enrichment system		Fuel injection
Ignition control system			TCI
Maximum generator output	V, A		12, 50
Spark plug		BKR7EKU (NGK)
Cooling system			Water
Exhaust system		Propeller boss
Lubrication system			Oil injection

1

2

3

4

5

6

7

8

9

6D03F1X

16

SPEC

Specifications

Item	Unit		Model
		Z300AETO		LZ300AETO
Fuel and oil
Fuel type		Regular unleaded gasoline
Fuel minimum rating	RON(*1)		90
	PON		86
Engine oil(*2)		YAMALUBE 2-stroke outboard motor oil
Engine oil tank capacity
Oil tank	L (US gal,	1.2 (0.32, 0.26)
	lmp gal)
Remote oil tank	L (US gal,	10.5 (2.77, 2.31)
	lmp gal)
Gear oil type		Hypoid gear oil
Gear oil grade	SAE		90
Gear oil quantity	cm3 (US oz,
		1,150 (38.9, 40.6)		1,000 (33.8, 35.3)
	lmp oz)
Bracket unit
Trim angle	Degree	–3 to 16
(at 12° boat transom)
Tilt-up angle	Degree		70
Steering angle	Degree	30 + 30
Drive unit
Gear shift positions			F-N-R
Gear ratio		1.75 (28/16)
Reduction gear type		Spiral bevel gear
Clutch type		Dog clutch
Propeller shaft type			Spline
Propeller direction (rear view)
		Clockwise		Counterclockwise
Propeller mark		T, M		TL, ML
Electrical
Battery minimum capacity(*3)
CCA/EN	A		711
20HR/IEC	Ah		100

(*1) RON: Research Octane Number

PON: Pump Octane Number = (RON + Motor Octane Number)/2

(*2) If 2-stroke outboard motor oil is not available, a 2- stroke NMMA-certified TC-W3 oil of equivalent quality must be used.

(*3) CCA: Cold Cranking Ampere

EN: European Norm (European standard) IEC: International Electrotechnical Commission

17

6D03F1X

General specifications / Maintenance specifications

Maintenance specifications

Power unit

Item	Unit	Model
		Z300AETO		LZ300AETO
Power unit
Minimum compression	kPa	580 (5.8, 84)
pressure*	(kgf/cm2, psi)
Cylinder heads
Warpage limit	mm (in)	0.1 (0.004)
(lines indicate straightedge
position)
Cylinders
Bore size	mm (in)	93.000–93.020	(3.6614–3.6622)
Bore size limit	mm (in)	93.100	(3.6654)
Taper limit	mm (in)	0.08 (0.0031)
Out-of-round limit	mm (in)	0.05 (0.0020)
Pistons
Piston diameter (D)	mm (in)	92.830–92.850	(3.6547–3.6555)
Measuring point (H)	mm (in)	10 (0.39)
Piston-to-cylinder clearance	mm (in)	0.165–0.171 (0.0065–0.0067)
Piston pin boss bore	mm (in)	26.004–26.015	(1.0238–1.0242)
Oversize piston
1st	mm (in)	0.25 (0.010)
2nd	mm (in)	0.50 (0.020)
Oversize piston diameter
1st	mm (in)	93.080–93.100	(3.6646–3.6653)
2nd	mm (in)	93.330–93.350	(3.6744–3.6752)
Piston pins
Outside diameter	mm (in)	25.995–26.000	(1.0234–1.0236)

*Measuring conditions:

Ambient temperature 20 °C (68 °F), wide open throttle, with spark plugs removed from all cylinders.

The figures are for reference only.

6D03F1X

18

SPEC

Specifications

Item	Unit	Model
		Z300AETO		LZ300AETO
Piston rings
Top ring
Dimension B	mm (in)	2.05	(0.0807)
Dimension T	mm (in)	3.00–3.20	(0.118–0.126)
End gap	mm (in)	0.30–0.50 (0.0118–0.0197)
Side clearance	mm (in)	0.02–0.06 (0.0008–0.0024)
2nd piston ring
Dimension B	mm (in)	2.05	(0.0807)
Dimension T	mm (in)	2.70–2.90	(0.106–0.114)
End gap	mm (in)	0.30–0.45 (0.0118–0.0177)
Side clearance	mm (in)	0.02–0.06 (0.0008–0.0024)
Connecting rods
Small end inside diameter	mm (in)	31.000–31.012 (1.2205–1.2209)
Big end side clearance	mm (in)	0.12–0.26 (0.0047–0.0102)
Small end axial play limit	mm (in)	2.0 (0.08)
Crankshaft
Crankshaft journal diameter	mm (in)	58.975–58.991 (2.3219–2.3225)
Crankpin diameter	mm (in)	40.485–40.500 (1.5939–1.5945)
Runout limit	mm (in)	0.02	(0.0008)
Thermostats
Opening temperature	°C (°F)	48–52	(118–126)
Fully open temperature	°C (°F)	60 (140)
Valve open lower limit	mm (in)	4.3 (0.17)
Oil pump
Identification mark		6D000
Bleeding		Screw type
Reed valves
Valve stopper height limit	mm (in)	8 (0.31)
Valve bending limit	mm (in)	0.2	(0.008)

19

6D03F1X

			Maintenance specifications
Lower unit
Item		Unit		Model
			Z300AETO		LZ300AETO
Gear backlash
Pinion-to-forward gear		mm (in)	0.12–0.44		0.30–0.62
			(0.0047–0.0173)		(0.0118–0.0244)
Pinion-to-reverse gear		mm (in)
			0.61–0.90 (0.0240–0.0354)
Pinion shims		mm	0.10, 0.12, 0.15, 0.18, 0.30, 0.40, 0.50
Forward gear shims		mm	0.10, 0.12, 0.15, 0.18, 0.30, 0.40, 0.50
Reverse gear shims		mm	0.10, 0.12, 0.15, 0.18, 0.30, 0.40, 0.50
Propeller shaft shims		mm
			—		0.10, 0.12, 0.15, 0.18,
					0.30, 0.40, 0.50
Propeller shaft
End play		mm (in)	—		0.25–0.35
					(0.0098–0.0138)
Electrical
Item		Unit		Model
			Z300AETO		LZ300AETO
Ignition and ignition control
system
Ignition timing (cylinder #1)		Degree	ATDC 7 at engine idle speed
		Degree	BTDC 14 at 5,500 r/min
Spark plug gap		mm (in)	1.5–1.6 (0.059–0.063)
Ignition coil resistance
Primary coil	(R – B/W)
at 20 °C (68 °F)		Ω	1.36–1.84
Secondary coil
(R – spark plug wire)
at 20 °C (68 °F)		kΩ	7.31–9.89
ECM output peak voltage
	(R – B/W)
at cranking (loaded)		V		265
at 1,500 r/min (loaded)		V		240
at 3,500 r/min (loaded)		V		240
Pulser coil output peak voltage
(W/R, W/B, W/Y, W/G,
W/L, W/Br – B)
at cranking (unloaded)		V		3.5
at cranking (loaded)		V		3.5
at 1,500 r/min (loaded)		V		20.0
at 3,500 r/min (loaded)		V		30.0

6D03F1X

20