TOHATSU M 2.5A2 User manual

OWNER’S
MANUAL
トーハツ船外機オーナーズマニュアル
Original instructions
M.A

M.B

OB No.--AK
M.A


ENOM00001-0
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.
Copyright © 2019 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.

3
YOUR TOHATSU OUTBOARD MOTOR
ENOM00006-A
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 proce-
dures 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.
Please always keep this manual together with the outboard motor as a reference to
everyone who uses the outboard motor. If the outboard motor is resold, make sure the
manual is passed on to the next owner.
We hope you will enjoy your outboard motor and wish you good luck in your boating
adventures.
TOHATSU CORPORATION
ENOM00003-0
PRE-DELIVERY CHECK
Be sure that the product has been checked by an authorized TOHATSU dealer before
you take delivery.
ENOM00113-0
EC DECLARATION OF CONFORMITY (DoC)
This product conforms to certain portion of the European Parliament directive. DoC
contains the following information;
zName and Address of the manufacturer.
zApplied community directives
zReference standard
zDescription of the product. (Model name and serial number)
zSignature of the responsible person (Name / Title / Date and place of issue).
ENON00937-0
Note
For CE marked model
The Outboard engine is intended to install on non-recreational craft within the European Union
because it has not been confirmed compliance with requirement of Directive 2013/53/EU.

4
ENOM00005-A
Serial Number
In the space below, please record the outboard motor's serial number. The serial num-
ber will be needed when ordering parts, and when making technical or warranty inquir-
ies.
Serial Number:
Serial Number: Date of purchase:
ENOF02000-0
ENOF02001-0

5
ENOM00007-0
NOTICE: DANGER/WARNING/CAUTION/Note
Before installing, operating or otherwise handling your outboard motor, be sure to thor-
oughly read and understand this Owner's Manual and carefully follow all of the instruc-
tions. 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.
ENOW00001-0
Failure to observe will result in severe personal injury or death, and possibly property damage.
ENOW00002-0
Failure to observe could result in severe personal injury or death, or property damage.
ENOW00003-0
Failure to observe could result in personal injury or property damage.
ENON00001-0
Note
This instruction provides special information to facilitate the use or maintenance of the outboard
motor or to clarify important points.
DANGER
WARNING
CAUTION

1. GENERAL SAFETY INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
2. SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
3. PARTS NAME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
4. LABEL LOCATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5. INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
1. Mounting the outboard motor on boat . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
6. PRE-OPERATING PREPARATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
1. Fuel handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2. Engine oil recommendation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3. Fuel filling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
4. Break-In . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
7. ENGINE OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Before starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
1. Fuel feeding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2. Starting the engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3. Warming up the engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4. Forward, reverse, and acceleration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
5. Stopping the engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
6. Steering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
7. Trim angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
8. Tilt up and down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
8. REMOVING AND CARRYING THE OUTBOARD MOTOR. . . . . . . . . . . . . . . . . . . .37
1. Removing the outboard motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
2. Carrying the outboard motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
3. Traillering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
9. ADJUSTMENT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
1. Steering friction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
10. INSPECTION AND MAINTENANCE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
1. Daily Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
2. Periodic Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
3. Off-season storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
4. Pre-season check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
5. Submerged outboard motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
6. Cold weather precautions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
7. Striking underwater object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
8. Auxiliary outboard motor operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
11. TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
12. TOOL KIT AND SPARE PARTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
13. PROPELLER TABLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
CONTENTS

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

10
1
GENERAL SAFETY INFORMATION
ENOM00009-0
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 out-
board motor should be shifted to neutral and shut off.
ENOW00005-0
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.
ENOM0008-A
EMERGENCY STOP SWITCH
The Emergency Stop Switch will stall the outboard motor when the stop switch lanyard
is pulled off. This stop switch lanyard has to be attached to the operator of the out-
board motor to minimize or prevent injuries from the propeller in case the operator
falls overboard.
It is operator’s responsibility to use the Emergency Stop Switch Lanyard.
ENOW00004-A
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 lanyard is coiled and can extended to a full 1300 mm (51 inch.).
ENOM00800-A
PERSONAL FLOTATION DEVICE
As the operator/driver and passenger of the boat, you are responsible to wear a PFD
(Personal Flotation Device) while on the boat.
WARNING
WARNING

GENERAL SAFETY INFORMATION 11
1
ENOM00010-0
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 recom-
mended lubricants.
ENOM00011-A
MAINTENANCE
As the owner of this outboard motor, you should be acquainted with correct mainte-
nance procedures following maintenance section of this manual (See page 40). 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.
Carbon Monoxide Poisoning Hazard
Exhaust gas contains carbon monoxide, a colorless and odorless gas which can be fatal
if inhaled for any length of time.
Never start or operate the engine indoors or in any space which is not well ventilated.
Gasoline
Gasoline and its vapors are very flammable and can be explosive. Use extreme care
when handling gasoline. You should be thoroughly knowledgeable on how to correctly
handle gasoline by reading this manual.

12
2
SPECIFICATIONS
ENOM00810-B
MODEL FEATURE
*1: Option
ENOM00811-B
MODEL NAME EXAMPLE
M3.5B2S
Model M2.5A2 M3.5A2 M3.5B2
Type MF MF MF
Transom heights
Sz z z
Lz z z
UL
Tiller Handle z z z
Remote Control
Separate fuel tank
Integral fuel tank z z z
Shifting z
Manual tilt z z z
M3.5 B 2 S
Model description Horse power Product genera-
tion Minor change Shaft length
M (X)= Two stroke
F= Four stroke
D= Two stroke DI -A and up 2 and up S= Short 15 in
L= Long 20 in
UL= Ultra long 25 in

SPECIFICATIONS 13
2
ENOM01300-0
Remark: Specifications subject to change without notice.
Tohatsu outboard is power rated in accordance with ISO8655 (propeller shaft output).
2.5A2, 3.5A2, 3.5B2
Item MODEL 2.5A2 3.5A2 3.5B2
Overall Length mm (in) 550 (21.7)
Overall Width mm (in) 345 (13.6) 220 (8.7)
Overall Height S mm (in) 955 (37.6)
L mm (in) 1082 (42.6)
Transom Height S mm (in) 435 (17.1)
L mm (in) 562 (22.1)
Weight S kg (lb) 12.5 (28) 13.0 (29)
L kg (lb) 13.0 (29) 13.5 (30)
Output kW (ps) 1.8 (2.5) 2.6 (3.5)
Max. Operating Range min
-1
(rpm) 3,800-5,200 4,200-5,300
Trolling Speed in Forward Gear min
-1
(rpm) 1,100
Idle Speed in Neutral Gear min
-1
(rpm) -1,300
Engine Type 2-Stroke
Number of Cylinders 1
Bore x Stroke mm (in) 47 x 43 (1.85 x 1.69)
Piston Displacement mL (Cu in) 74.6 (4.55)
Exhaust System Underwater exhaust
Cooling System Forced water cooling
Lubrication System Engine Oil Mixed Gasoline
Starting System Manual starter
Ignition System Flywheel Magneto C.D. Ignition
Spark Plugs NGK BP6HS-10/BPR6HS-10
Trim Position 4
Fuel Unleaded regular gasoline : Pump posted 87 Octane
(research octane rating of 91)
Fuel Tank Capacity L (US gal) Approx. 1.4 (0.37) integral tank
Engine Oil Genuine motor oil or recommended one (TCW-III)
Fuel : Engine Oil Mixing Retio Unleaded Gasoline 50 : Genuine 2-stroke Engine Oil 1
Gear Oil mL (fl.oz) Genuine Gear Oil or API GL5, SAE #80 to #90,
approx. 3.5B2:180 (6.1), 3.5A2 & 2.5A2:90 (3.0),
Gear Shift Foward F-N
Gear Reduction Ratio 1.85 (13 : 24) 2.15 (13 : 28)
Operator Sound Pressure
(ICOMIA 39/94) dB (A) 81.8
Hand Vibration Level
(ICOMIA 38/94) m/s25.1

14
3
PARTS NAME
ENOM01301-0
2.5A2, 3.5A2, 3.5B2
1
2
3
9
10
20
21
18
17
16
15
12
14
13
22
11
24
19
4
5
7
8
23
25
27
26
28
30
29
6
ENOF02002-0
1 Air Vent Screw
2 Fuel Tank Cap
3 Top Cowl
4 Plug Cap Cover
5 Fuel Cock
6 Cooling Warter Check Port
7 Clamp Bracket
8 Drive Shaft housing
9 Propeller
10 Water Inlet (2.5/3.5A2)
11 Starter Handle
12 Shift Lever(3.5B2 only)
13 Handle Grip
14 Carring Handle
15 Clamp Screw
16 Thrust Rod
17 Oil Plug (Upper)
18 Anti-Ventilation Plate
19 Water Inlet (3.5B2 only)
20 Gear Case
21 Oil Plug (Lower)
22 Throttle Lever
23 Tilt Stopper
24 Stop Switch
25 Carburetor Cover
26 Chork Lever
27 Drive Shaft Housing
Grommet (3.5B2 only)
28 Steering Friction
Adjustment Screw
29 Spark Plug
30 Fuel Filter

15
4
LABEL LOCATIONS
ENOM00019-A
1-1. Warning label urge to read the owner’s
manual.
1-2. Warning regarding stop switch (See
page 32).
2. Warning regarding fuel tank cap. (See
page20, 25)
3. Warning regarding high temperature.
Warning label locations
4, 5
2
3
1
ENOF02003-1
314X67531-3
2
1
ENOF02050-0
3GR-76191-0

LABEL LOCATIONS16
4
4. Warning label urge to read the
owner's manual.
5. Warning regarding high temperature,
high voltage, rotating object.
3F0X72185-0
314X72185-0

LABEL LOCATIONS 17
4
ENOM01001-0
1. Model code(Model name)
2. Rated power
3. Dry mass weight
4. Serial No.
5. Manufacture name
6. Manufacture address
ENON00937-0
Note
For CE marked model
The Outboard engine is intended to install on non-recreational craft within the European Union
because it has not been confirmed compliance with requirement of Directive 2013/53/EU.
Serial number label locations
Description of serial number year code
Last two digits of alphabet represent production year as below.
Year Code AK BX BA BB BC
Year of
manufacture 2019 2020 2021 2022 2023
:rewoPdetaR
ro
t
oMdra
o
bt
u
O
.oNlaireS
:ssaM
na
p
aJ
n
i
ed
aMCAN ICES-2/NMB-2
1)
2)
3)
4)
5)
6)
ENOF02048-1

18
5
INSTALLATION
ENOM00024-B
ENOW00006-0
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.
ENOW00009-0
zMounting the outboard motor without
following this manual can lead to unsafe
conditions such as poor maneuverability,
lack of control or fire.
zLoose clamp screws and/or mounting
bolts can lead to the release or displace-
ment of the outboard motor, possibly
resulting in lost of control and/or serious
personal injury. Be sure that fasteners are
tightened to the specified torque (30 Nm
(3.0 kgf) 13 ft-lb). Check the fasteners for
tightness from time to time.
zBe sure to use outboard mounting fasten-
ers included in the outboard motor pack-
age or their equivalents in terms of size,
material, quality and strength. Tighten
fasteners to the specified torque (30 Nm
(3.0 kgf) 13 ft-lb). Test cruise to check if
fasteners are tightened securely.
zOutboard motor mounting must be per-
formed by trained service person(s) using
lift or hoist with sufficient capacity.
Keep the outboard motor in a vertical
position when mounting.
1. Clamp Screw
2. Tighten
ENOM00025-0
Position ... Above keel line
Place the outboard motor in the center
of the boat's transom.
1. Center of boat
2. Boat transom
1. Mounting the outboard
motor on boat
WARNING
WARNING
ENOF02004-0
ENOF02005-0
1
2
2
1
ENOF01141-0

INSTALLATION 19
5
ENOM00026-0
Transom matching
Be sure that the anti ventilation plate of
the outboard motor is 30–50 mm (1.2–2
in) below the bottom of hull.
If the above condition cannot be met due
to the shape of the bottom of your boat,
please consult your authorized dealer.
1. Bottom of hull
2. Anti ventilation plate
ENOW00007-0
zBefore 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 sur-
face on the driveshaft housing. If the
water surface is near the bottom cowling,
in high waves, water may enter the engine
cylinders.
zIncorrect outboard motor mounting
height or existence of underwater
object(s), such as hull bottom design,
bottom surface conditions or underwater
accessories, can cause water spray possi-
bly reaching the engine through an open-
ing of the bottom cowling during cruising.
Exposing the engine to such conditions for
extended periods can lead to severe
engine damage.
ENOM00831-0
Mounting the outboard motor
1. Set the outboard motor to appropri-
ate position.
2. Tighten the clamp screws by turning
their handles.
3. Secure the outboard motor to the
boat with a rope to prevent acciden-
tal loss of the outboard motor over-
board.
ENON00930-0
Note
Do not use tools to tighten clamp screws.
Over tightening could result in damage to
the clamp screws and clamp brackets.
ENON00002-0
Note
A rope is not included in the standard
accessories.
CAUTION
1
2
30−50 mm
(1.2−2 in)
ENOF01608-0
ENOF02006-0

20
6
PRE-OPERATING PREPARATIONS
ENOM00030-A
ENOW000017-0
Use of improper gasoline can damage your
engine. Engine damage resulting from the
use of improper gasoline is considered mis-
use of the engine, and damage caused
thereby will not be covered under the lim-
ited warranty.
ENOM00031-A
FUEL RATING
TOHATSU engines will operate satisfacto-
rily when using a major brand of unleaded
gasoline meeting the following specifica-
tions:
USA and Canada — having a posted pump
Octane Rating of 87 (R+M)/2 minimum.
Premium gasoline (92 [R+M]/2 Octane) is
also acceptable. Do not use leaded gaso-
line.
Outside USA and Canada — Use
unleaded gasoline with declared octane
rating of 91 RON or over. Use of premium
gasoline of 98 RON is also allowed.
ENOM00032-A
GASOLINES CONTAINING
ALCOHOL
The fuel system components on your
TOHATSU engine will withstand up to 10%
ethyl alcohol (hererinafter referred to as
the "ethanol"), content in the gasoline.
But if the gasoline in your area contains
ethanol, you should be aware of certain
adverse effects that can occur. Increas-
ing the percentage of ethanol in the fuel
can also worsen these adverse effects.
Some of these adverse effects are
caused because the ethanol in the gaso-
line can absorb moisture from the air,
resulting in a separation of the water/
ethanol from the gasoline in the fuel tank.
These may cause increased:
zCorrosion of metal parts
zDeterioration of rubber or plastic parts
zFuel permeation through rubber fuel
lines
zStarting and operating difficulties
If the use of gasoline containing alcohol is
inevitable, or presence of alcohol is sus-
pected in the gasoline, it is recom-
mended to add a filter that has water
separating capability, and check the fuel
system for leaks and mechanical parts for
corrosion and abnormal wear more fre-
quently.
And, in case any of such abnormality is
found, discontinue the use of such gaso-
line and contact our dealer immediately.
If the outboard motor will only be used
infrequently, please see the remarks on
fuel deterioration in the STORAGE chap-
ter (P 51) for additional information.
ENOW00020-0
When operating a TOHATSU engine on gaso-
line containing alcohol, storage of gasoline in
the fuel tank for long periods should be
avoided. Long periods of storage, common
to boats, create unique problems. In cars,
alcohol blend fuels normally are consumed
before they can absorb enough moisture to
cause trouble, but boats often sit idle long
enough for phase separation to take place.
In addition, internal corrosion may take
place during storage if alcohol has washed
1. Fuel handling
CAUTION
CAUTION