Kubota WG972-E4 Operator's Manual

Liquid cooled gasoline/lpg/cng engine

Hide thumbs

Table Of Contents

Table of Contents

Quick Links

U.S.A.

: KUBOTA ENGINE AMERICA CORPORATION

505 Schelter Road, Lincolnshire, Illinois 60069 U.S.A.

Telephone : (847)955-2500

Canada

: KUBOTA CANADA LTD.

5900 14th Avenue, Markham, Ontario, L3S 4K4, Canada

Telephone : (905)294-7477

France

: KUBOTA EUROPE S.A.S

19-25, Rue Jules Vercruysse, Z.I. BP88, 95101 Ar enteuil Cedex, France

Telephone : (33)1-3426-3434

Italy

: KUBOTA EUROPE S.A.S Italy Branch

Via Grandi, 29 20068 Peschiera Borrome (MI) Italy

Telephone : (39)02-51650377

Germany

: KUBOTA (DEUTSCHLAND) GmbH

Senefelder Str. 3-5 63110 Rod au /Nieder-Roden, Germany

Telephone : (49)6106-873-0

U.K.

: KUBOTA (U.K.) LTD.

Dormer Road, Thame, Oxfordshire, OX9 3UN, U.K.

Telephone : (44)1844-214500

Australia

: KUBOTA TRACTOR AUSTRALIA PTY LTD.

25-29 Permas Way, Tru anina, VIC 3029, Australia

Telephone : (61)-3-9394-4400

Malaysia

: SIME KUBOTA SDN. BHD.

No.3 Jalan Sepadu 25/123 Taman Perindustrian Axis,

Seksyen 25, 40400 Shah Alam, Selan or Darul Ehsan Malaysia

Telephone : (60)3-736-1388

Philippines : KUBOTA PHILIPPINES, INC.

232 Quirino Hi hway, Baesa, Quezon City 1106, Philippines

Telephone : (63)2-422-3500

Indonesia : P.T. KUBOTA INDONESIA

Taman Industri Bukit Semaran Baru(BSB) Blok D.1 Kav.8, Kel. Jatibaran -

Kec.Mijen, Semaran , Indonesia

Telephone : (62)-24-7472849

Japan

: KUBOTA Corporation

En ine Export Dept.

2-47, Shikitsuhi ashi 1-chome, Naniwa-ku, Osaka, Japan 556-8601

Telephone : (81)6-6648-2155 Fax : (81)6-6648-3521

PRINTED IN JAPAN

Code No. EG821-8916-2

OPERATOR

KUBOTA

LIQUID COOLED

GASOLINE

LPG

1BGAAACAP0390

READ AND SAVE THIS BOOK

S MANUAL

CNG ENGINE

MODEL WG972-E4

Table of Contents

Need help?

Do you have a question about the WG972-E4 and is the answer not in the manual?

Questions and answers

stephen e gleason

April 21, 2025

on a wg9732-g-et what triggers the ignition? dies on a hot day after mowing

1 comments:

Mr. Anderson

May 11, 2025

The ignition on a Kubota WG972-E4 is triggered by the engine's ignition system, which includes components like the ignition coil, spark plugs, and ignition switch designed for gasoline or LPG operation.

The engine may die on a hot day after mowing due to overheating. Causes of overheating include:

- Insufficient engine oil
- Broken or loose fan belt
- Low coolant or improper antifreeze mix
- Clogged radiator net or fin
- Internal radiator corrosion or blockage
- Faulty fan, radiator, cap, thermostat, or temperature sensor
- Overload running
- Defective head gasket or coolant leak

These issues can reduce cooling efficiency, causing the engine to overheat and shut down.

This answer is automatically generated

Summary of Contents for Kubota WG972-E4

Page 1 Indonesia : P.T. KUBOTA INDONESIA Taman Industri Bukit Semaran Baru(BSB) Blok D.1 Kav.8, Kel. Jatibaran - Kec.Mijen, Semaran , Indonesia Telephone : (62)-24-7472849 Japan : KUBOTA Corporation En ine Export Dept. 2-47, Shikitsuhi ashi 1-chome, Naniwa-ku, Osaka, Japan 556-8601 Telephone : (81)6-6648-2155 Fax : (81)6-6648-3521 1BGAAACAP0390 Code No. EG821-8916-2 READ AND SAVE THIS BOOK PRINTED IN JAPAN © KUBOTA Corporation 2014...
Page 2 THE WG972-E4 ENGINE CONFORMS TO U.S. EPA PHASE 3 EXHAUST REGULATION AND CALIFORNIA EXHAUST EMISSION REGULATIONS FOR OFF-ROAD LARGE SI ENGINES. EMISSION COMPLIANCE PERIOD:1000 HOURS CARB EMISSIONS DURABILITY PERIOD: EXTENDED California Proposition 65 WARNING Engine exhaust, some of its constituents,...
Page 3 FOREWORD You are now the proud owner of a KUBOTA Engine. This engine is a product of KUBOTA quality engineering and manufacturing. It is made of fine materials and under a rigid quality control system. It will give you long, satisfactory service. To obtain the best use of your engine, please read this manual carefully.
Page 5: Table Of Contents
CONTENTS SAFE OPERATION ....................1 SERVICING OF THE ENGINE ..................1 IMPORTANT INFORMATION OF EMISSION REGULATION ........2 NAMES OF PARTS .....................3 PRE-OPERATION CHECK ..................5 BREAK-IN.........................5 DAILY CHECK......................5 OPERATING THE ENGINE ..................6 STARTING THE ENGINE (NORMAL)..............6 STOPPING THE ENGINE ..................8 CHECKS DURING OPERATION ................9 Radiator cooling water (Coolant)..................
Page 6 CONTENTS Gaseous fuel system...................... 23 Tightening torques and leak check for gas regulator with vaporizer ......23 Fuel system diagrams ....................23 ELECTRIC WIRING ....................25 FAN BELT ......................25 Adjusting fan belt tension ....................25 CARRIAGE AND STORAGE ..................26 CARRIAGE......................26 STORAGE ......................26 TROUBLESHOOTING ....................27 SPECIFICATIONS .....................30...
Page 7 UNAUTHORIZED MODIFICATIONS to the engine may impair the function and/or safety and affect engine life. If the engine does not perform properly, consult your local Kubota Engine Distributor first. 2. WEAR SAFE CLOTHING AND PERSONAL PROTECTIVE EQUIPMENT (PPE) A DO NOT wear loose, torn or bulky clothing around the...
Page 8 SAFE OPERATION 3. CHECK BEFORE STARTING & OPERATING THE ENGINE A Be sure to inspect the engine before operation. Do not operate the engine if there is something wrong with it. Repair it immediately. A Ensure all guards and shields are in place before operating the engine.
Page 9 SAFE OPERATION A If running the engine on LPG, use the standard LPG fuel recommended by KUBOTA. The use of other fuel may cause a hazardous or dangerous condition. A LPG fuel in the gaseous state is heavier than air and will settle in low areas, this may be hazardous.
Page 10 SAFE OPERATION 8. CAUTIONS AGAINST BURNS & BATTERY EXPLOSION A To avoid burns, be cautious of hot components, e.g. muffler, muffler cover, radiator, hoses, engine body, coolants, engine oil, etc. during operation and after the engine has been shut off. A DO NOT remove the radiator cap while the engine is running or immediately after stopping.
Page 11 A DO NOT mix different types of Anti-freeze. The mixture can produce a chemical reaction causing harmful substances. Use approved or genuine KUBOTA Anti-freeze. A Be mindful of the environment and the ecology. Before draining any fluids, determine the correct way to dispose of them.
Page 12 2. Clean warning and caution labels with soap and water, dry with a soft cloth. 3. Replace damaged or missing warning and caution labels with new labels from your local KUBOTA dealer. 4. If a component with warning and caution label(s) affixed is replaced with a new part, make sure the new label(s) is (are) attached in the same location(s) as the replaced component.
Page 13: Safe Operation
However, when in need of parts or major service, be sure to see your KUBOTA dealer. For service, contact the KUBOTA Dealership from which you purchased your engine or your local KUBOTA dealer. When in need of parts, be prepared to give your dealer the engine serial number.
Page 14: Important Information Of Emission Regulation
When operating WG972-GL, WG972-L, WG972-N on gaseous fuel, only a KUBOTA GENUINE REGULATOR KIT can be used. Only this regulator can be installed by an authorized KUBOTA DISTRIBUTOR or the manufacturer of the equipment in which this engine is used.
Page 15: Names Of Parts
NAMES OF PARTS NAMES OF PARTS Type Type Ref. Ref. Part Name Part Name Oil filler plug (13) Injector Ignition coil (14) Cooling fan Spark plug (15) Fan belt Engine hook (16) Fan drive pulley Exhaust manifold (17) Coolant drain cock Flywheel (18) Oil level gauge Starter...
Page 16 NAMES OF PARTS Type Ref. Part Name Sensor (O2) Catalytic muffler Catalytic converter Gas regulator G Type : WG972-G, GL Type : WG972-GL, L Type : WG972-L, N type : WG972-N...
Page 17: Pre-Operation Check
PRE-OPERATION CHECK PRE-OPERATION CHECK BREAK-IN During the engine break-in period, observe the following by all means: 1. Change engine oil and oil filter cartridge after the first 50 hours of operation. (See "ENGINE OIL" in "PERIODIC SERVICE" section.) 2. When ambient temperature is low, operate the machine after the engine has been completely warmed up. DAILY CHECK To prevent trouble from occurring, it is important to know the conditions of the engine well.
Page 18: Operating The Engine
OPERATING THE ENGINE OPERATING THE ENGINE STARTING THE ENGINE (NORMAL) To avoid personal injury or death: A Do not allow children to approach the machine while the engine is running. A Be sure to install the machine on which the engine is installed, on a flat place. A Do not run the engine on gradients.
Page 19 NOTE: "GASEOUS" position. *The step 1 above is for GL type only. *The fuel selector switch is not provided by KUBOTA. NOTE: *The step 2 above is for GL type only. *The fuel selector switch is not provided by KUBOTA.
Page 20: Stopping The Engine
OPERATING THE ENGINE STOPPING THE ENGINE LPG (CNG) Gasoline 1. Cool down the engine for 2 to 3 minutes. 1. Cool down the engine for 2 to 3 minutes. 2. Turn the starter switch to the "OFF" ( ) 2. Turn the starter switch to the "OFF" ( ) position.
Page 21: Checks During Operation
1. Engine oil level (See "ENGINE OIL" in "PERIODIC SERVICE" section.) BImmediately stop the engine if; A The engine suddenly slows down or accelerates. A Unusual noises are suddenly heard. BIf MIL (Malfunction Indicator Light) lights Consult your KUBOTA dealer.
Page 22: Maintenance
MAINTENANCE MAINTENANCE To avoid personal injury or death: A Be sure to conduct daily checks, periodic maintenance, refueling or cleaning on a level surface with the engine shut off and remove the key. A Before allowing other people to use your engine, explain how to operate, and have them read this manual before operation.
Page 23: Service Intervals
*1 Change more often when operating under dusty conditions. *2 If you do not have the proper tools and/or are not mechanically proficient, contact your local KUBOTA dealer. *3 This is not necessary to keep the emission related warranty valid.
Page 24 *1 Change more often when operating under dusty conditions. *2 If you do not have the proper tools and/or are not mechanically proficient, contact your local KUBOTA dealer. *3 This is not necessary to keep the emission related warranty valid.
Page 25 *1 Change more often when operating under dusty conditions. *2 If you do not have the proper tools and/or are not mechanically proficient, contact your local KUBOTA dealer. *3 This is not necessary to keep the emission related warranty valid.
Page 26 *1 Change more often when operating under dusty conditions. *2 If you do not have the proper tools and/or are not mechanically proficient, contact your local KUBOTA dealer. *3 This is not necessary to keep the emission related warranty valid.
Page 27: Periodic Service
1. Use unleaded gasoline and E10 only. [CNG: WG972-N] 1. Use Commercial CNG only. 2. Consult KUBOTA for further info of fuel used. A DO NOT use gasoline blended with methyl alcohol. BFuel level check and refueling A Be sure that the fill up valve and the liquid withdrawal valve are closed.
Page 28: Engine Oil
PERIODIC SERVICE ENGINE OIL BChecking oil level and adding engine oil 1. Check the engine oil level before starting or more than 5 minutes after stopping the engine. To avoid personal injury or death: 2. Remove the oil level gauge, wipe it clean and reinstall A Be sure to stop the engine before checking and changing the engine 3.
Page 29: Changing Engine Oil
PERIODIC SERVICE BChanging engine oil BReplacing the oil filter cartridge To avoid personal injury or death: To avoid personal injury or death: A Be sure to stop the engine before A Be sure to stop the engine before draining engine oil. changing the oil filter cartridge.
Page 30: Spark Plug
PERIODIC SERVICE SPARK PLUG RADIATOR Coolant will last for one day's work if filled all the way up BCleaning and adjustment clearance before operation start. Make it a rule to check the coolant If the spark plug electrode or its insulator is soiled or is level before every operation.
Page 31: Changing Coolant
When it is caution and securely retighten the cap. between the "FULL" and "LOW" marks, the coolant A If coolant should be leak, consult your local KUBOTA will last for one day's work. dealer.
Page 32: Checking Radiator Hoses And Clamp Bands
Always use a 50/50 mix of long-life coolant and clean soft water in KUBOTA engines. BCleaning radiator core (outside) Contact KUBOTA concerning coolant for extreme If dust is between the fin and tube, wash it away with conditions. running water.
Page 33: Air Cleaner
If mixed with the cleaning agent, sludge may build up, adversely affecting the engine parts. 7. Kubota's genuine long-life coolant has a service life of 1 year. Be sure to change the coolant every year. A The above data represents industry standards that...
Page 34: Evacuator Valve
PERIODIC SERVICE BEvacuator valve BDust indicator (optional) Open the evacuator valve once a week under ordinary If the red signal on the dust indicator attached to the air conditions - or daily when used in a dusty place - to get rid cleaner is visible, the air cleaner has reached the service of large particles of dust and dirt.
Page 35: Fuel System And Diagrams
A All fuel connections added to this engine must be installed by qualified personnel and utilizing recognized procedures and standards. A These non-KUBOTA installed parts, such as hoses, fittings, piping and shut off solenoid valve should be approved for LPG or CNG use and conform to UL, CSA, NFPA,MSHA and all other applicable standards.
Page 36 (4) CNG tank (with manual valve) (5) LPG tank (with manual valve) A The -marked component parts are Not Provided by KUBOTA. A Recommend: Install the lock off valve before the high pressure regulator and install the pressure sensor of CNG tank.
Page 37: Electric Wiring
PERIODIC SERVICE ELECTRIC WIRING FAN BELT BAdjusting fan belt tension To avoid personal injury or death: C Shorting of electric cable or wiring To avoid personal injury or death: may cause a fire. A Be sure to stop the engine and A Check to see if electric cables and remove the key before checking the wiring are swollen, hardened or...
Page 38: Carriage And Storage
CARRIAGE AND STORAGE CARRIAGE AND STORAGE CARRIAGE STORAGE To avoid personal injury or death: To avoid personal injury or death: A Fix the engine securely not to fall A Do not clean the machine with engine during operation. running. A Do not stand near or under the A To avoid the danger of exhaust fume engine while carrying it.
Page 39: Troubleshooting
TROUBLESHOOTING TROUBLESHOOTING The engine malfunctions can result from a large number of causes. The following describes symptoms that are encountered relatively more often than others, their major causes and remedies. B When it is difficult to start the engine Cause Countermeasures Check the fuel tank, fuel filter, fuel hoses and fuel pump.
Page 40 TROUBLESHOOTING B When engine speed is insufficient Cause Countermeasures Improper or defective spark plug * Clean or replace. Defective ignition coil * Replace. Defective throttle body * Replace. Breather tube has separated. * Attach correctly. Improper input signal to ECU * Check the wire harness.
Page 41 Overload running * Reduce load. Head gasket defective or water * Replace parts. leakage A If the cause of trouble can not be found, consult your KUBOTA dealer. A If MIL (Malfunction Indicator Light) lights up, consult your KUBOTA dealer.
Page 42: Specifications
SPECIFICATIONS SPECIFICATIONS WG972-G-E4 WG972-GL-E4 Model Gasoline Gasoline Type Vertical, Water-cooled 4 cycle No. of cylinders - bore x stroke mm (in.) 3- 74.5 x 73.6 (2.93 x 2.90) Total displacement L (cu-in.) 0.962 (58.68) SAE Gross kW(HP) / 24.2 (32.5) / 23.2 (31.1) / 22.0 (29.5) / intermittent...
Page 43 SPECIFICATIONS WG972-L-E4 WG972-N-E4 Model Type Vertical, Water-cooled 4 cycle No. of cylinders - bore x stroke mm (in.) 3- 74.5 x 73.6 (2.93 x 2.90) Total displacement L (cu-in.) 0.962 (58.68) SAE Gross kW(HP) / 22.0 (29.5) / 3600 20.4 (27.4) / 3600 intermittent min (rpm) SAE net...

Kubota WG972-E4 Operator's Manual

Quick Links

Need help?

Questions and answers

Subscribe to Our Youtube Channel

Related Manuals for Kubota WG972-E4

Summary of Contents for Kubota WG972-E4

Table of Contents