TOHATSU MFS 8A3 User manual

MANUAL
8A3
9.8A3
MFS
OWNER’S
OB No.003-11082-5

Copyright © 2009 Tohatsu Corporation. All rights reserved. No part of this manual may
be reproduced or transmitted in any from or by any means without the express written
permission of Tohatsu Corporation.
READ THIS MANUAL BEFORE USING THE OUTBOARD MOTOR. FAILURE TO FOLLOW THE
INSTRUCTIONS AND SAFETY PRECAUTIONS IN THIS MANUAL CAN RESULT IN SERIOUS
INJURY OR DEATH. KEEP THIS MANUAL IN A SAFE LOCATION FOR FUTURE REFERENCE.
!

YOUR TOHATSU OUTBOARD MOTOR
OWNER REGISTRATION AND IDENTIFICATION
Upon purchasing this product, be sure that the WARRANTY CARD is correctly and
completely filled out and mailed to the addressee noted there on. This WARRANTY
CARD identifies you as the legal owner of the product and serves as your warranty
registration.
IF THIS PROCEDURE IS NOT FOLLOWED, YOUR OUTBOARD MOTOR WILL
NOT BE COVERED BY THE APPLICABLE LIMITED WARRANTY.
PRE-DELIVERY CHECK
Be sure that the product has been checked by an authorized TOHATSU dealer
before you take delivery.
Limited Warranty
Please refer to the TOHATSU outboard motor Limited warranty provided to you with
this product, the terms and conditions of which, as amended from time to time, are
incorporated by reference into the manual.

Serial Number
In the space below, please record the outboard motor's serial number (indicated
both on the lower motor cover and on the cylinder block). The serial number will be
needed in the event of theft or to quickly identifying the outboard motor type.
Serial Number :
To You, Our Customer
Thank you for selecting a TOHATSU outboard motor. You are now the proud owner
of an excellent outboard motor that will service you for many years to come.
This manual should be read in its entirety and the inspection and maintenance
procedures described later in this manual should be followed carefully. Should
a problem arise with the outboard motor, please follow the troubleshooting
procedures listed at the end of this manual. If the problem persists, contact an
authorized TOHATSU service shop or dealer.
We hope you will enjoy your outboard motor and wish you good luck in your
boating adventures.
TOHATSU CORPORATION

GENERAL SAFETY INFORMATION･･･････････････････････････････････
SPECIFICATIONS･･･････････････････････････････････････････････････
NAMES OF PARTS･･････････････････････････････････････････････････
INSTALLATION･････････････････････････････････････････････････････
1. Mounting the outboard motor on boat･･･････････････････････････････
2. Installing the remote control devices････････････････････････････････
3. Installing the battery･･････････････････････････････････････････････
PRE-OPERATING PREPARATIONS･･･････････････････････････････････
1.Gasoline and engine oil････････････････････････････････････････････
2.Break-in･････････････････････････････････････････････････････････
3.Engine oil warning lamp･･･････････････････････････････････････････
4.ESG････････････････････････････････････････････････････････････
ENGINE OPERATION･･･････････････････････････････････････････････
Before starting･････････････････････････････････････････････････････
1.Starting･･････････････････････････････････････････････････････････
2.Warming up the engine････････････････････････････････････････････
3.Forward and reverse･･････････････････････････････････････････････
4.Stopping･････････････････････････････････････････････････････････
5.Trim angle･･･････････････････････････････････････････････････････
6.Tilt up, tilt down and shallow water operation･････････････････････････
7.Shallow water operation･･･････････････････････････････････････････
REMOVING AND CARRYING THE OUTBOARD MOTOR････････････････
1.Removing the outboard motor･･････････････････････････････････････
2.Carrying the outboard motor ･･･････････････････････････････････････
3.Storing the outboard motor･････････････････････････････････････････
TRAILERING･･･････････････････････････････････････････････････････
ADJUSTMENT･･････････････････････････････････････････････････････
1.Steering friction･･･････････････････････････････････････････････････
2.Throttle grip･･････････････････････････････････････････････････････
3.Reverse lock･････････････････････････････････････････････････････
4.Remote Control Lever Load････････････････････････････････････････
5.Trim Tab Adjustment･･････････････････････････････････････････････
INSPECTION AND MAINTENANCE･･･････････････････････････････････
1.Daily inspection ･･････････････････････････････････････････････････
2.Periodic inspection････････････････････････････････････････････････
3.Off-season storage････････････････････････････････････････････････
4.Pre-season check ････････････････････････････････････････････････
5.Motor submerged in water･････････････････････････････････････････
6.Cold weather precautions･･････････････････････････････････････････
7.Checking after striking underwater object････････････････････････････
TROUBLESHOOTING･･･････････････････････････････････････････････
TOOL KIT AND SPARE PARTS･･･････････････････････････････････････
OPTIONAL ACCESSORIES･･････････････････････････････････････････
PROPELLER TABLE････････････････････････････････････････････････
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CONTENTS

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1
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5
6
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8
9
10
11
12
13
1. SPECIFICATIONS
2. NAMES OF PARTS
3. INSTALLATION
4.PRE-OPERATING PREPARATIONS
5.ENGINE OPERATION
6. REMOVING AND CARRYING THE OUTBOARD MOTOR
7.TRAILERING
8.ADJUSTMENT
9.INSPECTION AND MAINTENANCE
10.TROUBLESHOOTING
11.TOOL KIT AND SPARE PARTS
12.OPTIONAL ACCESSORIES
13.PROPELLER TABLE
INDEX
GENERAL SAFETY INFORMATION

NOTICE : DANGER/WARNING/CAUTION/Note
Before installing, operating or otherwise handling your outboard motor, be sure
to thoroughly read and understand this Owner's Manual and carefully follow all of
the instructions. Of particular importance is information preceded by the words
"DANGER," "WARNING," "CAUTION," and "Note." Always pay special attention to
such information to ensure safe operation of the outboard motor at all times.
EMERGENCY STOP SWITCH
The Emergency Stop Switch will stall the outboard motor when the stop switch
tether is pulled off. This stop switch tether can be attached to the operator of
the outboard motor to minimize or prevent injuries from the propeller in case the
operator falls overboard.
We highly recommend use of the Emergency Stop Switch tether.
Failure to observe will result in severe personal injury or death, and possibly property damage.
!
Note
This instruction provides special information to facilitate the use or maintenance of the
outboard motor or to clarify important points.
Failure to observe could result in personal injury or property damage.
!
!
Failure to observe could result in severe personal injury or death, or property damage.
GENERAL SAFETY INFORMATION
!
Accidental activation of the Emergency Stop Switch (such as the tether being pulled out
in heavy seas) could cause passengers to lose their balance and even fall overboard, or it
could result in loss of power in heavy seas, strong currents, or high winds. Loss of control
while mooring is another potential hazard.
To minimize accidental activation of the Emergency Stop Switch, the 500 mm (20 inch.)
stop switch tether is coiled and can extended to a full 1,300 mm (51 inch.).

SAFE OPERATION OF BOAT
As the operator/driver of the boat, you are responsible for the safety of those
aboard and those in other boat around yours, and for following local boating
regulations. You should be thoroughly knowledgeable on how to correctly operate
the boat, outboard motor, and accessories. To learn about the correct operation
and maintenance of the outboard motor, please read through this manual carefully.
It is very difficult for a person standing or floating in the water to take evasive action
should he or she see a power boat heading in his /her direction, even at a slow
speed. Therefore, when your boat is in the immediate vicinity of people in the water,
the outboard motor should be shifted to neutral and shut off.
SERVICING, REPLACEMENT PARTS & LUBRICANTS
We recommend that only an authorized service shop perform service or
maintenance on this outboard motor. Be sure to use genuine parts, genuine
lubricants, or recommended lubricants.
MAINTENANCE
As the owner of this outboard motor, you should be acquainted with correct
maintenance procedures. It is the operator's responsibility to perform all safety
checks and to ensure that all lubrication and maintenance instructions are
complied with for safe operation. Please comply with all instructions concerning
lubrication and maintenance. You should take the engine to an authorized dealer
or service shop for periodic inspection at the prescribed intervals.
Correct periodic maintenance and proper care of this outboard motor will reduce
the chance of problems and limit overall operating expenses.
MOUNTING
Outboard motor mounting must be performed by trained service person(s) using
lift or hoist with sufficient capacity.
!
SERIOUS INJURY IS LIKELY IF A PERSON IN THE WATER MAKES CONTACT WITH
A MOVING BOAT, GEAR HOUSING, PROPELLER, OR ANY SOLID DEVICE RIGIDLY
ATTACHED TO A BOAT OR GEAR HOUSING.

MODEL
Item
8A3 9.8A3
MF EF EP
Overall Length mm (in) 975 (38.4) 590 (23.2)
Overall Width mm (in) 354 (13.9) 320 (12.6)
Overall Height S·L·UL mm (in) 1,035 (40.7) · 1,162 (45.7) · 1,289 (50.7)
Transom Height S·L·UL mm (in) 435 (17.1) · 562 (22.1) · 689 (27.1)
Weight
S Kg (lb) 37.0 (81.5) 40.0 (88.0) 40.0 (88.0)
L Kg (lb) 38.0 (84.0) 41.0 (90.5) 41.0 (90.5)
UL Kg (lb) 39.5 (87.0) 42.5 (93.5) 42.5 (93.5)
Output kW (Hp) 5.9 (8) 7.2 (9.8)
Max. Operating Range rpm 5,000-6,000
Idle Speed in Forward Gear rpm 900
Idle Speed in Neutral Gear rpm 950
Engine Type 4-Stroke
Number of Cylinder 2
Bore × Stroke mm (in) 55 × 44 (2.17 × 1.73)
Piston Displacement mL (Cu in) 209 (12.8)
Exhaust System Through hub exhaust
Cooling System Water cooling
Engine Lubrication Trochoid pump
Startring System Manual Electric starter motor ＊
Ignition System Flywheel Magneto C.D. ignition
Spark Plug NGK DCPR6E
Trim Position 6 3
Engine Oil NMMA FC-W certified 10W-30 or
API SF, SG, SH, SJ, SL or SM, 10W-30/40, Approx. 800mL
Gear Oil Genuine Gear Oil or API GL5,
SAE #80-90, Approx. 320mL
Fuel Tank Capacity L (US gal) 12 (3.17)
Gear Reduction Ratio 2.08 (13 : 27)
＊: with manual ※Specifications subject to change without notice.
10
14
13
12
11
10
9
8
7
6
5
4
3
2
1
MF , EF , EP
SPECIFICATIONS

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8
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13
SPECIFICATIONS
MODEL
Item
8A3 9.8A3
EFT EPT
Overall Length mm (in) 975 (38.4) 590 (23.2)
Overall Width mm (in) 354 (13.9) 320 (12.6)
Overall Height S·L·UL mm (in) 1,035 (40.7) · 1,162 (45.7) · 1,289 (50.7)
Transom Height S·L·UL mm (in) 435 (17.1) · 562 (22.1) · 689 (27.1)
Weight
S Kg (lb) 46.5 (102.5) 46.0 (101.4)
L Kg (lb) 47.5 (104.7) 47.0 (103.6)
UL Kg (lb) 49.0 (108) 48.5 (106.9)
Output kW (Hp) 5.9 (8) 7.2 (9.8)
Max. Operating Range rpm 5,000-6,000
Idle Speed in Forward Gear rpm 900
Idle Speed in Neutral Gear rpm 950
Engine Type 4-Stroke
Number of Cylinder 2
Bore × Stroke mm (in) 55 × 44 (2.17 × 1.73)
Piston Displacement mL (Cu in) 209 (12.8)
Exhaust System Through hub exhaust
Cooling System Water cooling
Engine Lubrication Trochoid pump
Startring System Electric starter motor ＊
Ignition System Flywheel Magneto C.D. ignition
Spark Plug NGK DCPR6E
Trim Position 6 3
Engine Oil NMMA FC-W certified 10W-30 or
API SF, SG, SH, SJ, SL or SM, 10W-30/40, Approx. 800mL
Gear Oil Genuine Gear Oil or API GL5,
SAE #80-90, Approx. 320mL
Fuel Tank Capacity L (US gal) 12 (3.17)
Gear Reduction Ratio 2.08 (13 : 27)
＊: with manual ※Specifications subject to change without notice.
EFT , EPT

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EP type only
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＊：MF and EF type only.
☆：EF type only.
①
②
③
④
⑤
⑥
⑦
⑧
⑨
⑩
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11
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Tilt Handle
Top Cowl
Cowl Latch
Cooling Water Check Port
Oil Drain Bolt
Water Plug
Anti Ventilation Plate
Anode / Trim Tab
Water Inlet
Propeller
Oil Plug (Lower) (Fill)
Oil Plug (Upper) (Level)
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Drive Shaft Housing
Thrust Rod
Clamp Bracket
Clamp Screw
＊Shift Lever
＊Throttle Grip
Starter Handle
Warning Lamp
Fuel Connector
☆Starter Switch
Stop Switch
＊Choke Knob
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25
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26
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27
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28
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29
○
30
○
31
○
32
○
33
○
34
○
35
Primer Bulb
Fuel Tank Cap
Air Vent Screw
Fuel Connector
Fuel Pick up Elbow
Fuel Tank
Remote Control Box
Main Switch
Stop Switch
Cord Assembly
Engine Stop Switch Cord
12
14
13
12
11
10
9
8
7
6
5
4
3
2
1
MF , EF , EP
NAMES OF PARTS

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23
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20
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21
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22
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24
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26
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28
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27
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29
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30
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31
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32
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33
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34
EPT type only
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35
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25
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1
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2
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3
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8
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9
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11
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10
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13
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14
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15
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16
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17
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18
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19
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12
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4
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5
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6
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7
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16
＊：EFT type only.
☆：EPT type only.
①
②
③
④
⑤
⑥
⑦
⑧
⑨
⑩
○
11
○
12
Tilt Handle
Top Cowl
Cowl Latch
Cooling Water Check Port
Oil Drain Bolt
Water Plug
Anti Ventilation Plate
Anode / Trim Tab
Water Inlet
Propeller
Oil Plug (Lower) (Fill)
Oil Plug (Upper) (Level)
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13
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14
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15
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16
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17
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18
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19
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20
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21
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22
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23
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24
Drive Shaft Housing
Clamp Bracket
Clamp Screw
＊Power tilt switch
＊Throttle Grip
＊Shift Lever
Starter Handle
Oil warning Lamp
Fuel Connector
☆Starter Switch
Stop Switch
＊Choke Knob
○
25
○
26
○
27
○
28
○
29
○
30
○
31
○
32
○
33
○
34
○
35
Primer Bulb
Fuel Tank Cap
Air Vent Screw
Fuel Connector
Fuel Pick up Elbow
Fuel Tank
Remote Control Box
Main Switch
Stop Switch
Cord Assembly
Engine Stop Switch Cord
EFT , EPT
13
1
2
3
4
5
6
7
8
9
10
11
12
13
NAME OF PARTS

Bottom of hull
Anti Ventilation Plate
5-25mm
(0.2-1”)
Position ... Above keel line
Set engine at center of boat.
Transom matching
Be sure that the anti ventilation plate of
the outboard motor is below the water
surface when running with the throttle
wide open.
If the above condition cannot be met
due to the shape of the bottom of your
boat, please consult your authorized
dealer.
14
14
13
12
11
10
9
8
7
6
5
4
3
2
1
!
Most boats are rated and certified
in terms of their maximum allowable
horsepower, as shown on the boat’s
certification plate. Do not equip your boat
with an outboard motor that exceeds this
limit. If in doubt, contact your dealer.
Do not operate the outboard motor until it
has been securely mounted on the boat
in accordance with the instructions below.
1. Mounting the outboard motor on boat
INSTALLATION
Boat Transom
Center of Boat
●Before beginning the running test,
check that the boat with maximum
capacity loading floats on the water in
a proper attitude. Check the position
of water surface on the driveshaft
housing. If the water surface is near
the bottom cowling, in high waves,
water may enter the engine cylinders.
●Incorrect outboard motor mounting
height or existence of underwater
object(s), such as hull bottom
design, bottom surface conditions or
underwater accessories, can cause
production of water spray possibly
reaching the engine through an
opening of the bottom cowling
during cruising. Exposing engine
to such conditions for extended
periods can lead to severe engine
damage.
!

MF, EF, EP type
①To attach the outboard motor to the
boat, tighten the clamp screws by
turning their handles.
Also, tighten the bolts. Secure
the outboard motor with a rope to
prevent loss overboard.
15
1
2
3
4
5
6
7
8
9
10
11
12
13
Notes
1. Apply sealing agent such as silicone
sealed between the bolts and
transom board holes before tightening
the bolts.
2. Be sure to tighten mounting bolt nuts
to the specified torque.
(30 Nm(3.0kgf)13ft·lb)
Note
It is recommended to install upper
mounting bolts with bolt head at
inside surface of transom. Bolts with
threaded end at inside surface of
transom can cause personal injury.
INSTALLATION
Note
The rope is not included in the standard
accessories.
!
●Mounting outboard motor without
following this manual can lead to unsafe
conditions such as poor maneuverability,
going out of control or fire disaster.
●Loose clamp screws and/or mounting
bolts can lead to coming off or
displacement of outboard motor,
possibly going out of control or causing
serious personal injury. Be sure that
fasteners are tightened to the specified
torque (30 Nm (3.0kgf)13ft·lb). Check
fasteners for tightness from time to time.
●Be sure to use outboard mounting
fasteners included in outboard motor
package delivered or their equivalents
in terms of size, material, quality and
strength.
Tighten fasteners to the specified torque
(30 Nm (3.0kgf)13ft·lb). Test cruise
to check if fasteners are tightened
securely.
●Outboard motor mounting must be
performed by trained service person(s)
using lift or hoist with sufficient capacity.
Clamp Screw
Nut
Washer
Bolt
EP
＊Bolt (8×85) Clamp Screw
＊Nut
＊Washer
＊: Option
MF & EF
＊: Option

EFT, EPT type (Power tilt model)
16
14
13
12
11
10
9
8
7
6
5
4
3
2
1
INSTALLATION
Notes
1. Apply sealing agent such as silicone
sealed between the bolts and
transom board holes before tightening
the bolts.
2. Be sure to tighten mounting bolt nuts
to the specified torque.
(30 Nm(3.0kgf)13ft·lb)
Note
It is recommended to install upper
mounting bolts with bolt head at
inside surface of transom. Bolts with
threaded end at inside surface of
transom can cause personal injury.
!
●Mounting outboard motor without
following this manual can lead to unsafe
conditions such as poor maneuverability,
going out of control or fire disaster.
●Loose clamp screws and/or mounting
bolts can lead to coming off or
displacement of outboard motor,
possibly going out of control or causing
serious personal injury. Be sure that
fasteners are tightened to the specified
torque (30 Nm (3.0kgf)13ft·lb). Check
fasteners for tightness from time to time.
●Be sure to use outboard mounting
fasteners included in outboard motor
package delivered or their equivalents
in terms of size, material, quality and
strength.
Tighten fasteners to the specified torque
(30 Nm (3.0kgf)13ft·lb). Test cruise
to check if fasteners are tightened
securely.
●Outboard motor mounting must be
performed by trained service person(s)
using lift or hoist with sufficient capacity.

It is recommended that you consult
with your authorized dealer for
installation and adjustment of the
remote control device.
■Installation of the Remote Control
Cables (Box side) :
Follow the instruction manual
provided with the remote control.
■Installation of the Remote Control
on your boat :
Follow the instruction manual
provided with the remote control.
■Installation of the Remote Control
Cable (engine side) and the Cord
Assembly (Wiring Harness) :
①Fitting of connecting parts to
cables
Screw the tip of the remote control
cable into the cable joint up to
approx. 10 mm (0.39 inch), then lock
them with a lock nut. Apply grease to
the hole of the cable joint.
② Fitting of Remote Control Cable to
Engine.
17
1
2
3
4
5
6
7
8
9
10
11
12
13
INSTALLATION
2. Installing the remote control devices
Cable joint
Approx. 10mm
(0.39 inch)
Remoto control cable
Lock nut
Note
Put the control lever in the Neutral
position and the Free Accel lever in
the fully closed position.
Cable Harness
Throttle CableShift Cable
Note
Confirm the engine shifts correctly
when the shift lever is placed in
Forward and Reverse position. also
confirm the throttle valve is closed
at idle, in Neutral, Forward, and
Reverse. Confirm the throttle valve
is fully open when in Forward at the
wide open position.
Be careful not to loop remote control
cables to diameter of 406 mm (16
inches) or less.
!

Green
Green
Red
Red
Red
Red
Blue
Blue
Blue
Yellow
Brown
Brown
Brown
Brown
Black
Black
Black
Drag link
Sleeve
From
Remote
Control Box
Brown
Brown
Black
Black Green
Blue
Red
③ Connecting the Cord assembly
(Wiring Harness)
Pass the Cord assembly from the
Remote control box through the
hole in the Lower motor cover and
cover the wire ends with the Sleeve
(provided in a tool bag) and then
connect the electric terminals
according to the drawing below.
EP model
EP model
18
14
13
12
11
10
9
8
7
6
5
4
3
2
1
INSTALLATION
!
Do not disconnect cord ass'y when
engine is in operation, or engine will go
out of control.

Green
Green
Red
Red
Red
Red
Blue
Blue
Blue
Yellow
Brown
Brown
Brown
Brown
Black
Black
Black
Red
Sky blue
Pink
EPT model
19
1
2
3
4
5
6
7
8
9
10
11
12
13
INSTALLATION
②Connect the positive cord (+) to the
positive terminal (+) of the battery,
and then connect the negative
cord (−). When disconnecting
the battery always remove the
negative cord (−) first. After
connecting the positive terminal
(+), securely place a cap on it to
prevent short circuits.
●Make sure that the battery cords do
not get stuck between the outboard
motor and boat when turning, etc.
●The starter motor may fail to
operate if the cords are incorrectly
connected.
●Be sure to correctly connect the (+)
and (−) cords. If not, the charging
system will be damaged.
●Do not disconnect the battery cords
from battery while the engine is
operating, the electrical parts could
be damaged.
●Always use a fully charged battery.
!
Battery cord
(black)
Battery cord
(red)
Do not use a battery that is not
recommended. Use of a battery
not recommended can lead to poor
performance of, and / or damage to,
the electrical system.
!

①P l a c e t h e b at t e r y b ox i n a
convenient position away from
water spray. Securely fasten both
the box and the battery so they do
not shake loose.
20
14
13
12
11
10
9
8
7
6
5
4
3
2
1
INSTALLATION
!
Battery generates explosive hydrogen
gas. Be sure to:
●Charge the battery in a well-ventilated
place.
●Place the battery away from any
source of fire, sparks and open
flames such as burners or welding
equipment.
●Do not smoke when handling the
battery.
●Do not smoke near the battery when
the battery is charging.
3. Installing the battery
Note
Minimum recommended battery : 12V,
70AH or 12V, 40AH
Specifications and features of batteries
vary among the manufacturers. Consult
the manufacturer for details.
!
Battery electrolyte contains sulfuric acid
and thus is hazardous, causing a burn
if it comes in contact with your skin, or
poisonous if swallowed.
KEEP BATTERY AND ELECTROLYTE
AWAY FROM REACH OF CHILDREN
When handling the battery, be sure to:
●Read all warnings shown on the
battery case
●Prevent electrolyte from coming in
contact with any part of your body.
Contact can cause serious burn or,
if it comes in contact with your eye,
loss of sight. Use safety glasses and
rubber gloves.
In case battery electrolyte comes in
contact with:
●Skin, flush thoroughly with water.
●Eye, flush thoroughly with water,
and then seek immediate medical
treatment.
In case battery electrolyte is swallowed:
●Seek immediate medical treatment.