Kubota WG1605-G-E3, WG1605-GL-E3, WG1605-L-E3 Workshop Manual

WORKSHOP MANUAL

KiSC issued 01, 2012 A

GASOLINE,LPG ENGINE

WG1605-G-E3,WG1605-L-E3,

WG1605-GL-E3

TO THE READER

KiSC issued 01, 2012 A

This Workshop Manual tells the servicing personnel about the mechanism, servicing and

maintenance of the WG1605-G-E3, WG1605-L-E3 and WG1605-GL-E3. It contains 4 parts:
"Information", "General", "Mechanism" and "Servicing".

 Information

This section contains information below.

• Safety First

• Specification

• Important Items of Exhaust Emission Regulation

• Performance Curve

• Dimension

• Wiring Diagram

 General

This section contains information below.

• Engine Identification

• General Precautions

• Maintenance Check List

• Check and Maintenance

• Special Tools

 Mechanism

This section contains information on the structure and the function of the unit. Before you continue

with the subsequent sections, make sure that you read this section.

 Servicing

This section contains information below.

• Troubleshooting

• Servicing Specifications

• Tightening Torques

• Checking, Disassembling and Servicing

All illustrations, photographs and specifications contained in this manual are of the newest

information available at the time of publication.

KUBOTA reserves the right to change all information at any time without notice.
Since this manual includes many models, information or illustrations and photographs can show

more than one model.

January, 2012

© KUBOTA Corporation 2012

I INFORMATION

KiSC issued 01, 2012 A

INFORMATION

KiSC issued 01, 2012 A

CONTENTS

1. SAFETY FIRST .............................................................................................................................. I-1

2. SPECIFICATIONS.......................................................................................................................... I-4

3. IMPORTANT ITEMS OF EXHAUST EMISSION REGULATION.................................................... I-6

[1] THREE-WAY CATALYST ........................................................................................................ I-7

[2] VAPORIZER AND LOCK OFF VALVE

(WG1605-L-E3, WG1605-GL-E3) ............................................................................................ I-7

[3] LENGTH OF THE VAPOR HOSE

(WG1605-L-E3, WG1605-GL-E3) ........................................................................................... I-7

[4] IMPORTANT NOTICE .............................................................................................................. I-7

[5] EMISSION-RELATED INSTALLATION INSTRUCTIONS ........................................................ I-7

(1) Exhaust System.................................................................................................................. I-7

(2) Intake System..................................................................................................................... I-7

(3) Crankcase Ventilation Connections.................................................................................... I-7

(4) Gasoline Fuel System ........................................................................................................ I-7

(5) Gaseous Fuel System ........................................................................................................ I-7

(6) Engine Control Unit (ECU) ................................................................................................. I-8

(7) Vehicle Interface Connectors ............................................................................................. I-8

(8) Malfunction Indicator Light (MIL) ........................................................................................ I-8

4. PERFORMANCE CURVES ............................................................................................................I-9

5. DIMENSIONS ............................................................................................................................... I-10

6. WIRING DIAGRAM....................................................................................................................... I-12

WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, WSM

SAFETY FIRST

DANGER

WARNING

CAUTION

IMPORTANT

NOTE

KiSC issued 01, 2012 A

INFORMATION

1. SAFETY FIRST

• This symbol, the industry's "Safety Alert Symbol", is used throughout this manual and on labels on the
machine itself to warn of the possibility of personal injury. Read these instructions carefully.

• It is essential that you read the instructions and safety regulations before you attempt to repair or use
this unit.

• Indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury.

• Indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.

• Indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate
injury.

• Indicates that equipment or property damage could result if instructions are not followed.

• Gives helpful information.

WSM000001INI0001US1

BEFORE YOU START SERVICE

• Read all instructions and safety instructions in this
manual and on your engine safety decals.

• Clean the work area and engine.

• Park the machine on a stable and level ground.

• Let the temperature of the engine decrease before
you start a job.

• Stop the engine, then remove the key.

• Disconnect the battery negative cable.

• Hang a "DO NOT OPERATE" tag in the operator
station.

WSM000001INI0002US0

START SAFELY

• Do not do the procedures below when you start the
engine.
– short across starter terminals
– bypass the safety start switch

• Do not make unauthorized modifications to the
engine. This can cause damage and decrease the
engine life.

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WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, WSM

KiSC issued 01, 2012 A

INFORMATION

OPERATE SAFELY

• Do not use the machine after you consume alcohol
or medication or when you are tired.

• Put on applicable clothing and safety equipment.

• Use applicable tools only. Do not use alternative
tools or parts.

• When 2 or more persons do servicing, make sure
that you do it safely.

• Do not touch the hot parts or parts that turn when the
engine operates.

• Do not remove the radiator cap when the engine
operates, or immediately after it stops. If not, hot
water can spout out from the radiator. Only remove
the radiator cap when it is at a sufficiently low
temperature to touch with bare hands. Slowly loosen
the cap to release the pressure before you remove it
fully.

• Released fluid (fuel or hydraulic oil) under pressure
can cause damage to the skin and cause serious
injury. Release the pressure before you disconnect
hydraulic or fuel lines. Tighten all connections before
you apply the pressure.

• Do not open a fuel system under high pressure.
The fluid under high pressure that stays in fuel lines
can cause serious injury. Do not disconnect or repair
the fuel lines, sensors, or any other components
between the fuel pump and injectors on engines with
a common rail fuel system under high pressure.

• Put on an applicable ear protective device (earmuffs
or earplugs) to prevent injury against loud noises.

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PREVENT A FIRE

• Fuel is very flammable and explosive under some
conditions. Do not smoke or let flames or sparks in
your work area.

• To prevent sparks from an accidental short circuit,
always disconnect the battery negative cable first
and connect it last.

• The battery gas can cause an explosion. Keep the
sparks and open flame away from the top of battery,
especially when you charge the battery.

• Make sure that you do not spill fuel on the engine.

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KEEP A GOOD AIRFLOW IN THE WORK AREA

• If the engine is in operation, make sure that the area
has good airflow. Do not operate the engine in a
closed area. The exhaust gas contains poisonous
carbon monoxide.

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KiSC issued 01, 2012 A

INFORMATION

DISCARD FLUIDS CORRECTLY

• Do not discard fluids on the ground, down the drain,
into a stream, pond, or lake. Obey related
environmental protection regulations when you
discard oil, fuel, coolant, electrolyte and other
dangerous waste.

WSM000001INI0007US1

PREVENT ACID BURNS

• Keep electrolyte away from your eyes, hands and
clothing. Sulfuric acid in battery electrolyte is
poisonous and it can burn your skin and clothing and
cause blindness. If you spill electrolyte on yourself,
clean yourself with water, and get medical aid
immediately.

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PREPARE FOR EMERGENCIES

• Keep a first aid kit and fire extinguisher ready at all
times.

• Keep the emergency contact telephone numbers
near your telephone at all times.

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2. SPECIFICATIONS

INFORMATION

Model

WG1605-G-E3 WG1605-L-E3

Gasoline fuel LPG fuel

Number of Cylinder 4

Type

Vertical, water cooled,

4-cycle Gasoline engine

Vertical, water cooled,

4-cycle LPG engine

Bore × Stroke 79.0 × 78.4 mm (3.11 × 3.09 in.)

Total Displacement 1.537 L (93.79 cu.in.)

-1

SAE Gross Intermittent

ISO / SAE Net Intermittent

ISO Net Continuous

Maximum Bare Speed

42.5 kW (57.0 HP) / 3600 min

37.0 kW (49.6 HP) / 3000 min

38.5 kW (51.6 HP) / 3600 min

33.5 kW (44.9 HP) / 3000 min

30.8 kW (41.3 HP) / 3600 min

26.8 kW (35.9 HP) / 3000 min

(rpm)

-1

(rpm)

-1

(rpm)

-1

(rpm)

-1

(rpm)

-1

(rpm)

3575 to 3625 min
2975 to 3025 min

Minimum Bare Idling Speed 725 to 775 min

41.0 kW (55.0 HP) / 3600 min

36.0 kW (48.3 HP) / 3000 min

37.1 kW (49.8 HP) / 3600 min

32.5 kW (43.6 HP) / 3000 min

29.7 kW (39.8 HP) / 3600 min

26.1 kW (35.0 HP) / 3000 min

-1

(rpm)

-1

(rpm)

-1

(rpm)

Cylinder Head Overhead-Valve

Ignition System Full Transistor Battery Ignition Type

Governor Electronic Governor

Direction of Rotation Counter-Clockwise (Viewed from Flywheel Side)

Spark Plug Type / Spark Plug Gap NGK IFR6F8DN 0.70 to 0.80 mm (0.028 to 0.031 in.)

0.35 rad (20 °) before T.D.C. /

-1

3000 min

750 min

(rpm), 3600 min-1 (rpm)

0.17 rad (10 °) before T.D.C. /

-1

(rpm), 800 min-1 (rpm)

Ignition Timing

0.45 rad (26 °) before T.D.C. /

-1

3000 min

750 min

(rpm), 3600 min-1 (rpm)

0.17 rad (10 °) before T.D.C. /

-1

(rpm), 800 min-1 (rpm)

Firing Order 1-3-4-2

Compression Ratio 9.1: 1

Lubricating System Forced Lubrication by Trochoid Pump

Oil Pressure Indication Electrical Type Switch

Lubricating Filter Full Flow Paper Filter (Cartridge Type)

Cooling System Pressurized Radiator, Forced Circulation with Water Pump

Starting System Electric Starting with Starter

Starting Motor 12 V, 1.0 kW

Battery 12 V, 52 AH or Equivalent

Charging Alternator 12 V, 480 W, 720 W

Fuel *Unleaded Automobile Gasoline Commercial LPG

Lubricating Oil Better than SL Class (API) SAE 10W-30

Lubricating Oil Capacity 6.0 L (1.6 U.S.gals)

Catalytic Muffler / Converter Three Way Catalyst

Weight (Dry) 119 kg (262 lbs) 120 kg (265 lbs)

Application General Power Source

*The specification described above is of the standard engine of each model.
*Conversion Formula: HP = 0.746 kW, PS = 0.7355 kW

-1

(rpm)

-1

(rpm)

-1

(rpm)

-1

(rpm)

-1

(rpm)

-1

(rpm)

*KUBOTA RECOMMENDED LPG FUEL SPECIFICATIONS

• Commercial Propane gas only.

• Equivalent to Propanes H-D-5 of GPA* standards.

(vol %)

C

3H8

≥ 90 % ≤ 5 % ≤ 2.5 % −

*GPA means Gas Processors Association (U.S.A.)

C3H

6

C4H

10

Others

I-4

WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, WSM

KiSC issued 01, 2012 A

INFORMATION

Model

Gasoline fuel LPG fuel

WG1605-GL-E3

Number of Cylinder 4

Type Vertical, water cooled, 4-cycle Dual Fuel (Gasoline / LPG) engine

Bore × Stroke 79.0 × 78.4 mm (3.11 × 3.09 in.)

Total Displacement 1.537 L (93.79 cu.in.)

-1

SAE Gross Intermittent

ISO / SAE Net Intermittent

ISO Net Continuous

Maximum Bare Speed

42.5 kW (57.0 HP) / 3600 min

37.0 kW (49.6 HP) / 3000 min

38.5 kW (51.6 HP) / 3600 min

33.5 kW (44.9 HP) / 3000 min

30.8 kW (41.3 HP) / 3600 min

26.8 kW (35.9 HP) / 3000 min

(rpm)

-1

(rpm)

-1

(rpm)

-1

(rpm)

-1

(rpm)

-1

(rpm)

3575 to 3625 min
2975 to 3025 min

Minimum Bare Idling Speed 725 to 775 min

41.0 kW (55.0 HP) / 3600 min

36.0 kW (48.3 HP) / 3000 min

37.1 kW (49.8 HP) / 3600 min

32.5 kW (43.6 HP) / 3000 min

29.7 kW (39.8 HP) / 3600 min

26.1 kW (35.0 HP) / 3000 min

-1

(rpm)

-1

(rpm)

-1

(rpm)

Cylinder Head Overhead-Valve

Ignition System Full Transistor Battery Ignition Type

Governor Electronic Governor

Direction of Rotation Counter-Clockwise (Viewed from Flywheel Side)

Spark Plug Type / Spark Plug Gap NGK IFR6F8DN 0.70 to 0.80 mm (0.028 to 0.031 in.)

0.35 rad (20 °) before T.D.C. /

-1

3000 min

750 min

(rpm), 3600 min-1 (rpm)

0.17 rad (10 °) before T.D.C. /

-1

(rpm), 800 min-1 (rpm)

Ignition Timing

0.45 rad (26 °) before T.D.C. /

-1

3000 min

750 min

(rpm), 3600 min-1 (rpm)

0.17 rad (10 °) before T.D.C. /

-1

(rpm), 800 min-1 (rpm)

Firing Order 1-3-4-2

Compression Ratio 9.1: 1

Lubricating System Forced Lubrication by Trochoid Pump

Oil Pressure Indication Electrical Type Switch

Lubricating Filter Full Flow Paper Filter (Cartridge Type)

Cooling System Pressurized Radiator, Forced Circulation with Water Pump

Starting System Electric Starting with Starter

Starting Motor 12 V, 1.0 kW

Battery 12 V, 52 AH or Equivalent

Charging Alternator 12 V, 480 W, 720 W

Fuel *Unleaded Automobile Gasoline Commercial LPG

Lubricating Oil Better than SL Class (API) SAE 10W-30

Lubricating Oil Capacity 6.0 L (1.6 U.S.gals)

Catalytic Muffler / Converter Three Way Catalyst

Weight (Dry) 121 kg (267 lbs)

Application General Power Source

*The specification described above is of the standard engine of each model.
*Conversion Formula: HP = 0.746 kW, PS = 0.7355 kW

-1

(rpm)

-1

(rpm)

-1

(rpm)

-1

(rpm)

-1

(rpm)

-1

(rpm)

*KUBOTA RECOMMENDED LPG FUEL SPECIFICATIONS

• Commercial Propane gas only.

• Equivalent to Propanes H-D-5 of GPA* standards.

(vol %)

*GPA means Gas Processors Association (U.S.A.)

C

3H8

C3H

6

C4H

10

Others

≥ 90 % ≤ 5 % ≤ 2.5 % −

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WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, WSM

KiSC issued 01, 2012 A

INFORMATION

3. IMPORTANT ITEMS OF EXHAUST EMISSION REGULATION

WG1605 is available and unavailable in those countries.

kW, Disp. Model Type

19 < P, 1.0 < L

WG1605-G-E3, WG1605-L-E3,
WG1605-GL-E3

E3 Available Available Non-available

Current and future emission regulations.

Countries kW, disp. 2009 2010 2011 2012 2013 2014 2015 2016

CARB

USA

EPA

Canada 19 < P None

Japan 19 ≤ P < 560 HC/0.6 g/kWh, NO

EU 19 < P None

• *: with evaporative emission regulation

• **: See figure below

19 < P < 560

1.0 < L

19 < P ≤ 560

1.0 < L

2.7/4.4* ** 0.8/20.6*

2.7/4.4* **

/0.6 g/kWh, CO/20 g/kWh

x

North

America

Europe Japan

HC+NOx/CO (g/kWh)

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WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, WSM

KiSC issued 01, 2012 A

INFORMATION

[1] THREE-WAY CATALYST

A three-way catalyst is a catalyst that oxidizes HC to CO2 and H2O and also CO to CO2 respectively and at the

same time reduces NOx to N

The main basic component of an exhaust gas purification system that uses a three-way catalyst is feedback
control of air-fuel ratio by means of an O
characteristic with reference to the intake air-fuel ratio of the three-way catalyst.

near the stoichiometric ratio.

2

sensor for the purpose of maximizing the emission purification efficiency

2

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[2] VAPORIZER AND LOCK OFF VALVE

(WG1605-L-E3, WG1605-GL-E3)

Vaporizer requires a normally-closed electrically controlled fuel lock off valve that is close coupled to the vaporizer
and off when ignition switch is off or when the engine is not running normally (supplied from Kubota). In operation
without a lock off upstream the vaporizer will flow fuel with the engine off. The vaporizer is not a fuel shut-off safety
device.

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[3] LENGTH OF THE VAPOR HOSE

(WG1605-L-E3, WG1605-GL-E3)

Vapor hose length must not exceed 700 mm (27.6 in), shorter is generally considered better. Care should be
taken with hose routing and length to minimize the affect on vaporizer vibration isolation. The metal reinforced hose
should not be used.

9Y1210661INI0007US0

[4] IMPORTANT NOTICE

These instructions are provided to the Final Engine Assemblers (FEA) who must ensure the engine, exhaust
system (catalyst), fuel system etc, are installed correctly in the engine's certified configuration.

Please confirm whether emission-related items are certain on application review.

(for EPA only)

Failing to follow these instructions when installing a certified engine in a piece of nonroad equipment violates
federal law (40 CFR 1068.105(b)), subject to fines or other penalties as described in the Clean Air Act.

The contractual agreement contract is necessary before mass-production.

9Y1210661INI0018US0

[5] EMISSION-RELATED INSTALLATION INSTRUCTIONS

(1) Exhaust System

Kubota supplies a certified catalyst. FEA must use a Kubota certified catalyst and assemble the exhaust system
parts according to the instructions.

No other catalyst is certified for use with WG1605 Engine. No Other Catalyst can be used.

FEA may only install the exhaust system parts confirmed at application review.

9Y1210661INI0019US0

(2) Intake System

To prevent decreases of engine output performance, intake resistance must be kept below a certain point.

9Y1210661INI0020US0

(3) Crankcase Ventilation Connections

Crankcase emissions may not be discharged directly into the ambient atmosphere throughout its useful life.
(40 CFR 1048.115 (a))

9Y1210661INI0021US0

(4) Gasoline Fuel System

standards of 40 CFR 1048.

(5) Gaseous Fuel System

according to the instructions.

If your equipment uses a volatile liquid fuel (such as gasoline), they must meet the evaporative emission

9Y1210661INI0022US0

FEA must use only the vaporizer and the lock off valve Kubota offers and assemble the LPG fuel system parts

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WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, WSM

KiSC issued 01, 2012 A

INFORMATION

(6) Engine Control Unit (ECU)

Installation must utilize all 4 of the vibration mounts.
ECU header pins must be horizontal or point downward.

9Y1210661INI0024US0

(7) Vehicle Interface Connectors

Vehicle interface connectors shall be connected with your wire harness.

9Y1210661INI0025US0

(8) Malfunction Indicator Light (MIL)

When the MIL goes on, it must display "Check Engine", "Service Engine Soon", or a similar message that EPA

approve. (40 CFR 1048.110 (b))

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WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, WSM

KiSC issued 01, 2012 A

4. PERFORMANCE CURVES

WG1605-G/L/GL-E3

INFORMATION

(1) Brake Horsepower
(2) Engine Speed
(3) Specific Fuel Consumption
(4) Torque
(5) Gross Intermittent Torque
(6) Gross Intermittent Brake

Horsepower

(7) Gross Intermittent Specific

Fuel Consumption

a: Gasoline Use
b: LP Gas Use

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KiSC issued 01, 2012 A

5. DIMENSIONS

WG1605-G-E3

INFORMATION

WG1605-L-E3

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KiSC issued 01, 2012 A

WG1605-GL-E3

INFORMATION

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KiSC issued 01, 2012 A

6. WIRING DIAGRAM

WG1605-G-E3

INFORMATION

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WG1605-L-E3

INFORMATION

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KiSC issued 01, 2012 A

WG1605-GL-E3

INFORMATION

I-14

G GENERAL

KiSC issued 01, 2012 A

GENERAL

KiSC issued 01, 2012 A

CONTENTS

1. Engine IDENTIFICATION ............................................................................................................. G-1

[1] ENGINE MODEL NAME, CODE NUMBER AND ENGINE SERIAL NUMBER ...................... G-1

[2] E3 ENGINE ............................................................................................................................ G-3

[3] CYLINDER NUMBER ............................................................................................................. G-3

[4] CATALYTIC CONVERTER .................................................................................................... G-4

2. GENERAL PRECAUTIONS.......................................................................................................... G-5

3. MAINTENANCE CHECK LIST ..................................................................................................... G-6

4. CHECK AND MAINTENANCE ..................................................................................................... G-7

[1] DAILY CHECK POINTS ......................................................................................................... G-7

[2] CHECK POINTS OF INTIAL 50 HOURS ............................................................................. G-10

[3] CHECK POINTS OF EVERY 50 HOURS ............................................................................ G-11

[4] CHECK POINTS OF EVERY 100 HOURS .......................................................................... G-12

[5] CHECK POINTS OF EVERY 200 HOURS .......................................................................... G-14

[6] CHECK POINTS OF EVERY 1000 HOURS ........................................................................ G-15

[7] CHECK POINTS OF EVERY 2000 HOURS ........................................................................ G-17

[8] CHECK POINTS OF EVERY 1 YEAR.................................................................................. G-17

[9] CHECK POINTS OF EVERY 2 YEARS ............................................................................... G-20

5. SPECIAL TOOLS ....................................................................................................................... G-24

WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, WSM

KiSC issued 01, 2012 A

GENERAL

1. Engine IDENTIFICATION

[1] ENGINE MODEL NAME, CODE NUMBER AND ENGINE SERIAL

NUMBER

When contacting the manufacture, always specify your engine model name, code number and serial number.
They are necessary to be identified before the engine can be serviced or parts replaced.

9Y1210661GEG0001US0

Engine Model Name and Number Label

The engine model number, the engine serial number and

engine code number are written in this label.

(1) Engine Model Name and Number

Label

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G-1

WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, WSM

KiSC issued 01, 2012 A

GENERAL

Engine Serial Number

The engine serial number is an identified number for the engine.

It is marked after the engine model name.

It indicates month and year of manufacture as follows.

Year of manufacture

Alphabet or

Number

1 2001 F 2015

2 2002 G 2016

3 2003 H 2017

4 2004 J 2018

5 2005 K 2019

6 2006 L 2020

7 2007 M 2021

8 2008 N 2022

9 2009 P 2023

A 2010 R 2024

B 2011 S 2025

C 2012 T 2026

D 2013 V 2027

E2014

Year

Alphabet or

Number

Year

(1) Engine Serial Number

Month of manufacture

Month Engine Lot Number

January A0001 ~ A9999 B0001 ~ BZ999

February C0001 ~ C9999 D0001 ~ DZ999

March E0001 ~ E9999 F0001 ~ FZ999

April G0001 ~ G9999 H0001 ~ HZ999

May J0001 ~ J9999 K0001 ~ KZ999

June L0001 ~ L9999 M0001 ~ MZ999

July N0001 ~ N9999 P0001 ~ PZ999

August Q0001 ~ Q9999 R0001 ~ RZ999

September S0001 ~ S9999 T0001 ~ TZ999

October U0001 ~ U9999 V0001 ~ VZ999

November W0001 ~ W9999 X0001 ~ XZ999

December Y0001 ~ Y9999 Z0001 ~ ZZ999

* Alphabetical letters "I" and "O" are not used.

e.g.

(a)

•WG1605

(a) Engine Model Name: WG1605
(b) Year: B indicates 2011
(c) Month: A or B indicates January
(d) Lot Number: (0001 ~ 9999 or A001 ~ Z999)

(b)B(c)

- B

(d)

A001

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WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, WSM

KiSC issued 01, 2012 A

[2] E3 ENGINE

GENERAL

[Example: Engine Model Name WG1605-G/L/GL-E3-XXXX]

The emission controls previously implemented in various
countries to prevent air pollution will be stepped up as Non-Road
Emission Standards continue to change. The timing or applicable
date of the specific Non-Road Emission regulations depends on the
engine displacement and output classification.

Over the past several years, KUBOTA has been supplying SI
engines that comply with regulations in the respective countries
affected by Non-Road Emission regulations. For KUBOTA Engines,
E3 will be the designation that identifies engine models affected by
the next emission phase (See the table below).

When servicing or repairing ###-E3 series engines, use only
replacement parts for that specific E3 engine, designated by the
appropriate E3 KUBOTA Parts List and perform all maintenance
services listed in the appropriate KUBOTA Operator's Manual or in
the appropriate E3 KUBOTA Workshop Manual. Use of incorrect
replacement parts or replacement parts from other emission level
engines (for example: E2 engines), may result in emission levels out
of compliance with the original E3 design and EPA or other
applicable regulations. Please refer to the emission label located on
the engine head cover to identify Engine Displacement and Output
classification and Emission Control Information. E3 engines are
identified with "ET" at the end of the Model designation, on the US
EPA label. Please note: E3 is not marked on the engine.

Category (1) EPA Regulation

ET Phase 3

[3] CYLINDER NUMBER

(1) "E3" engines are identified with "ET" at the end of the Model designation, on

the US EPA label.
"E3" designates Phase 3 / Tier 3 models, depending on engine displacement
and output classification.

[A] WG1605-G-E3
[B] WG1605-L-E3
[C] WG1605-GL-E3

9Y1210661GEG0037US0

The cylinder numbers of KUBOTA gasoline, gasoline / LPG and
natural gas engine are designated as shown in the figure.

The sequence of cylinder numbers is given as No.1, No.2, No.3
and No.4 starting from the gear case side.

9Y1210661GEG0006US0

G-3

WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, WSM

IMPORTANT

KiSC issued 01, 2012 A

[4] CATALYTIC CONVERTER

number are marked on surfaces of the catalyst parts as the catalyst
identification.

(1) Part Number (2) Date / Serial Number

GENERAL

KUBOTA provides the catalytic converter as the catalyst parts.
The parts number, the manufacturing date and the catalyst lot

• To trace of the catalytic converter, put down the catalyst
identification and engine identification when new service
catalytic converter is installed.

9Y1210661GEG0038US0

G-4

WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, WSM

KiSC issued 01, 2012 A

2. GENERAL PRECAUTIONS

• During disassembly, carefully arrange removed parts in a clean
area to prevent confusion later. Screws, bolts and nuts should
be replaced in their original position to prevent reassembly
errors.

• When special tools are required, use KUBOTA genuine special
tools. Special tools which are not frequently used should be
made according to the drawings provided.

• Before disassembling or servicing live wires, make sure to
always disconnect the grounding cable from the battery first.

• Remove oil and dirt from parts before measuring.

• Use only KUBOTA genuine parts for parts replacement to
maintain engine performance and to ensure safety.

• Gaskets and O-rings must be replaced during reassembly.
Apply grease to new O-rings or oil seals before assembling.

• When reassembling external or internal snap rings, position
them so that sharp edge faces against the direction from which
a force is applied.

• Be sure to perform run-in the serviced or reassemble engine.
Do not attempt to give heavy load at once, or serious damage
may result to the engine.

(1) Grease
(2) Force
(3) Place the Sharp Edge the Direction

of Force

GENERAL

(A) External Snap Ring
(B) Internal Snap Ring

9Y1210318GEG0007US0

G-5

WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, WSM

CAUTION

KiSC issued 01, 2012 A

GENERAL

3. MAINTENANCE CHECK LIST

To maintain long-lasting and safe engine performance, make it a rule to carry out regular inspections by following

the table below. (The schedule applies to an engine in use under normal conditions.)

[WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3]

Service Interval

Item

Checking engine oil level 

Checking and replenish coolant 

Checking air cleaner element

Cleaning air cleaner element

Checking LPG tank setting condition

Checking LPG fuel connector 

Changing engine oil 

Replacing oil filter cartridge 

Checking gasoline fuel hose and clamp
bands

Checking LPG fuel hose and clamp bands 

Cleaning spark plug 

Checking fuel filter 

Check fan belt tension and damage 

Checking battery electrolyte level 

Replacing fuel filter

Checking LPG tank setting condition 

Checking radiator hoses and clamp bands 

Checking PCV valve 

Checking coolant hose of LPG vaporizer 

Checking LPG Lock off valve 

Checking valve clearance 

Replacing spark plug 

* Replacing air cleaner element 

Replacing gasoline fuel hose, clamp bands
and fuel filter

Cleaning fuel tank inside (for gasoline fuel) 

Cleaning water jacket and radiator interior 

Replacing intake air line 

Replacing breather hose 

Replacing LPG fuel hose and clamp bands 

Replacing coolant hose of LPG vaporizer 

** Checking LPG vaporizer 

Replacing radiator hoses and clamp bands 

Changing radiator coolant 

Replacing battery 

Every

8hrs

(Daily)

if

necessary

if

necessary

if

necessary

Every

50 hrs

(Weekly)



Every

100 hrs



if

necessary

Every

200 hrs

Every

1000 hrs

Every

2000 hrs

Every

1 year



2 years

Every

 Change engine oil and replace oil filter cartridge after the first 50 hours of operation.
*: Change more often when operating under dusty conditions.
**: If you do not have the proper tools and / or are not mechanically proficient, contact your local KUBOTA dealer.

• When changing or inspecting, be sure to level and stop the engine.

9Y1210661GEG0008US0

G-6

WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, WSM

IMPORTANT

NOTE

KiSC issued 01, 2012 A

4. CHECK AND MAINTENANCE

[1] DAILY CHECK POINTS

Checking Engine Oil Level

1. Level the engine.

2. To check the oil level, draw out the dipstick (1), wipe it clean,
reinsert it, and draw it out again.
Check to see that the oil level lies between the two notches.

3. If the level is too low, add new oil to the specified level.

• When using an oil of different maker or viscosity from the
previous one, drain old oil. Never mix two different types of
oil.

• Use the proper SAE Engine oil according to ambient
temperatures.

• Be sure to inspect the engine, locating it on a horizontal
place. If placed on gradients, accurately, oil quantity may
not be measured.

• Be sure to keep the oil level between upper and lower limits
of the dipstick. Too much oil may cause a drop in output or
excessive blow-by gas. On the closed breather type engine
in which mist is sucked through port, too much oil may
caused oil hammer. While too little oil, may seize the
engine's rotating and sliding parts.

(1) Dipstick

GENERAL

9Y1210661GEG0009US0

G-7

WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, WSM

CAUTION

IMPORTANT

KiSC issued 01, 2012 A

GENERAL

Checking and Replenish Coolant

1. Without recovery tank:
Remove the radiator cap (1) and check to see that the coolant
level is just below the port.
With recovery tank (2):
Check to see that the coolant level lies between FULL"A" and
LOW "B".

2. If coolant level is too low, check the reason for decreasing
coolant.
(Case 1)
If coolant is decreasing by evaporation, replenish only fresh,
soft water.
(Case 2)
If coolant is decreasing by leak, replenish coolant of the same
manufacture and type in the specified mixture ratio (fresh, soft
water and L.L.C.). If the coolant brand cannot be identified,
drain out all of the remaining coolant and refill with a totally new
brand of coolant mix.

• Do not remove the radiator cap until coolant temperature is
below its boiling point. Then loosen the cap slightly to
relieve any excess pressure before removing the cap
completely.

• During filling the coolant, air must be vented from the
engine coolant passages. The air vents by jiggling the
radiator upper and lower hoses.

• Be sure to close the radiator cap securely. If the cap is
loose or improperly closed, coolant may leak out and the
engine could overheat.

• Do not use an antifreeze and scale inhibitor at the same
time.

• Never mix the different type or brand of L.L.C..

(1) Radiator Cap
(2) Recovery Tank

A: FULL
B: LOW

9Y1210571GEG0037US0

G-8

WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, WSM

NOTE

KiSC issued 01, 2012 A

GENERAL

Checking Air Cleaner Element (If necessary)

1. Remove the dust cup in the air cleaner.

2. Check the dust in the dust cup and the element.

(When reassembling)

• Install the air cleaner dust cup with "TOP" indicated on the rear

of the cup.

(1) Element
(2) Dust Cap

(3) "TOP" Mark

9Y1210571GEG0038US0

Cleaning Air Cleaner Element (If necessary)

1. Remove the air cleaner element.

2. Use clean dry compressed air on the inside of the element.
Pressure of compressed air must be under 205 kPa

2

(2.1 kgf/cm

, 30 psi).

Maintain reasonable distance between the nozzle and the filter

• The air cleaner uses a dry element. Never apply oil to it.

• Do not run the engine with filter element removed.

• Change the element once a year or every 6th cleaning

9Y1210661GEG0050US0

Checking LPG Tank Setting Condition (If necessary)
(WG1605-L-E3, WG1605-GL-E3)

1. Check the setting condition of LPG fuel tank.

9Y1210661GEG0010US0

Checking LPG Fuel Connector
(WG1605-L-E3, WG1605-GL-E3)

1. Check the connector of LPG line (hoses and clamps).

9Y1210661GEG0011US0

G-9

WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, WSM

CAUTION

IMPORTANT

CAUTION

IMPORTANT

KiSC issued 01, 2012 A

[2] CHECK POINTS OF INTIAL 50 HOURS

Changing Engine Oil

• Be sure to stop engine before changing engine oil.

1. Start and warm up the engine for approx. 5 minutes.

2. Place an oil pan underneath the engine.

3. To drain the used oil, remove the drain plug (1) at the bottom of
the engine and drain the oil completely.

4. Screw the drain plug (1).

5. Fill new oil up to upper line on the dipstick (2).

• When using an oil of different maker or viscosity from the
previous one, remove all of the old oil.

• Never mix two different types of oil.

• Engine oil should have properties of API classification
better than SH.

• Use the proper SAE Engine Oil according to ambient
temperature.

Above 25 °C (77 °F) SAE30 or SAE10W-30 or SAE15W-40

0 °C to 25 °C (32 °F to 77 °F) SAE20 or SAE10W-30

0 °C to −20 °C (32 °F to −4 °F) SAE10W or SAE10W-30

GENERAL

Engine oil capacity

Tightening torque Drain plug

(1) Drain Plug (2) Dipstick

6.0 L

1.6 U.S.gals

32.4 to 37.3 N·m

3.31 to 3.80 kgf·m

23.9 to 27.5 lbf·ft

9Y1210661GEG0012US0

Replacing Oil Filter Cartridge

• Be sure to stop the engine before changing filter cartridge.

1. Remove the oil filter cartridge (1) with the filter wrench.

2. Apply a slight coat of oil onto the new cartridge gasket.

3. To install the new cartridge, screw it in by hand. Over tightening
may cause deformation of rubber gasket.

4. After the new cartridge has been replaced, the engine oil
normally decrease a little. Thus see that the engine oil does not
leak through the seal and be sure to read the oil level on the
dipstick. Then, replenish the engine oil up to the specified level.

• To prevent serious damage to the engine, replacement
element must be highly efficient. Use only a KUBOTA
genuine filter or its equivalent.

(1) Engine Oil Filter Cartridge

9Y1210661GEG0013US0

G-10