Kubota GR2020G, GR2120, GR2120AU Operators Manual

OPERATOR'S MANUAL

AS . D . 1 - 1 . - . AK

Code No. K1270-7122-1

MODELS

GR2020G
GR2120
GR2120AU

G
R

2
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G

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G
R

2
1
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G
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2
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A
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1BDAHAOAP0580

PRINTED IN U.S.A.

KUBOTA Corporation 2014

©

READ AND SAVE THIS MANUAL

ABBREVIATION LIST

Abbreviations Definitions

API

PTO

PT

rpm

SAE

KRA

American Petroleum Institute

Power Take Off

Permanent Type (=Ethylene glycol anti-freeze)

Revolutions Per Minute

Society of Automotive Engineers

Kubota Reverse Awareness System

UNIVERSAL SYMBOLS

As a guide to the operation of your tractor, various universal symbols have been utilized on the instruments and
controls. The symbols are shown below with an indication of their meaning.

Safety Alert Symbol

Gasoline Fuel

Diesel Fuel

Coolant Temperature

Mower-Lowered position

Mower-Raised position

KUBOTA Corporation is ···

Since its inception in 1890, KUBOTA Corporation has grown to
rank as one of the major firms in Japan.

To achieve this status, the company has through the years
diversified the range of its products and services to a remarkable
extent. Nineteen plants and 16,000 employees produce over 1,000
different items, large and small.

All these products and all the services which accompany them,
however, are unified by one central commitment. KUBOTA makes
products which, taken on a national scale, are basic necessities.
Products which are indispensable. Products which are intended to
help individuals and nations fulfill the potential inherent in their
environment. KUBOTA is the Basic Necessities Giant.

Brake

Parking Brake

Engine-Stop

Engine-Run

Preheat

Starter Control

Power Take-Off Clutch Control-Off Position

Power Take-Off Clutch Control-On Position

Cutting Height

California Proposition 65

WARNING

Engine exhaust, some of its constituents,
certain vehicle components and fluids,
contain or emit chemicals known to the
State of California to cause cancer and birth
defects or other reproductive harm.

Headlight

Headlight-ON

Headlight-OFF

Fast

Slow

Engine Speed Control

Choke

Battery

Oil Pressure

IMPORTANT

The engine in this machine is not equipped by the manufacturer
with a standard spark arrester.
It is a violation of California Public Resource Code Section 4442 to
use or operate this engine on or near any forest-covered, brush­covered land, or grass- covered land unless the exhaust system is
equipped with a working spark arrester meeting state laws. Other
states or federal areas may have similar laws.

This potential includes water supply, food from the soil and from
the sea, industrial development, architecture and construction,
transportation.

Thousands of people depend on KUBOTA's know-how, technology,
experience and customer service. You too can depend on
KUBOTA.

The spark ignition system of GR2020G complies with Canadian ICES-002.

FOREWORD

You are now the proud owner of a KUBOTA LAWN AND GARDEN TRACTOR. This
machine is a product of KUBOTA's quality engineering and manufacturing. It is
made of excellent materials and under a rigid quality control system. It will give you
long, satisfactory service. To obtain the best use of your machine, please read this
manual carefully. It will help you become familiar with the operation of the machine
and contains many helpful hints about machine maintenance. It is KUBOTA's policy
to utilize, as quickly as possible, every advance in our research. The immediate use
of new techniques in the manufacturing of products may cause some small parts of
this manual to become outdated. KUBOTA distributors and dealers will have the
most up-to-date information. Please do not hesitate to consult them.

3

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 assemble or use this unit.

3
3
3

IMPORTANT :

NOTE :

DANGER :

WARNING :

CAUTION :

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, could result in minor or moderate injury.

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

Gives helpful information.

SAFETY FIRST

CONTENTS

SAFE OPERATION ............................................................................................ -1

SERVICING OF LAWN AND GARDEN TRACTOR .................................................... 1

SPECIFICATIONS....................................................................................................... 2

IMPLEMENT LIMITATIONS ........................................................................................ 4

INSTRUMENT PANEL AND CONTROLS................................................................... 6

MOWER MOUNTING .................................................................................................. 7

ATTACHING THE MOWER ..................................................................................... 7

Mounting the Mower Deck................................................................................................7

ADJUSTING THE PARALLEL LINKAGE................................................................. 9

ADJUSTING THE MOWER DECK (SIDE TO SIDE) ............................................... 9

ADJUSTING THE MOWER LIFT STOPPERS ...................................................... 10

DISMOUNTING THE MOWER DECK ................................................................... 10

OPERATING THE ENGINE....................................................................................... 11

STARTING THE ENGINE ...................................................................................... 11

Key Switch......................................................................................................................12

Throttle Lever and Choke Lever ..................................................................................... 13

Cold Weather Starting ....................................................................................................14

Block Heater (Option) ..................................................................................................... 14

STOPPING THE ENGINE...................................................................................... 14

Engine Stop (By manual)................................................................................................ 15

WARMING UP ....................................................................................................... 15

Warm-up and Transmission Oil in the Low Temperature Range....................................15

JUMP STARTING .................................................................................................. 16

HIGH ALTITUDE OPERATION.............................................................................. 16

OPERATING THE MACHINE.................................................................................... 17

OPERATING NEW MACHINE ............................................................................... 17

Changing Lubricating Oil for New Machines...................................................................17

Engine Break-in .............................................................................................................. 17

Machine Break-in............................................................................................................ 17

STARTING ............................................................................................................. 18

Operator's Seat...............................................................................................................18

Head Light Switch........................................................................................................... 18

Hydraulic Lift Lever.........................................................................................................19

Throttle Lever..................................................................................................................19

Parking Brake ................................................................................................................. 19

Speed Control Pedal.......................................................................................................20

Cruise Control Device..................................................................................................... 20

STOPPING............................................................................................................. 21

Stopping.......................................................................................................................... 21

CHECK DURING DRIVING ................................................................................... 21

Immediately Stop the Engine if:......................................................................................21

Easy Checker (TM)......................................................................................................... 21

Engine Overheating Precautions....................................................................................21

CONTENTS

Fuel Gauge.....................................................................................................................22

Hourmeter.......................................................................................................................22

PARKING ............................................................................................................... 23

Parking............................................................................................................................ 23

TRANSPORTING................................................................................................... 23

Directions for Use of Power Steering..............................................................................23

Glide Steer......................................................................................................................24

OPERATING THE MOWER ...................................................................................... 25

MAKING THE MOST OF YOUR MOWER............................................................. 25

ADJUSTING CUTTING HEIGHT ........................................................................... 25

Cutting Height Control Dial ............................................................................................. 25

OPERATING THE MOWER................................................................................... 27

KRA system Normal Operating Mode.............................................................................27

PTO Lever ......................................................................................................................28

KRA system Override Mode ...........................................................................................28

CLEANING ................................................................................................................ 30

CLEANING WITH WATER..................................................................................... 30

CLEANING THE MOWING SYSTEM .................................................................... 30

TIRE AND WHEELS.................................................................................................. 31

TIRES..................................................................................................................... 31

Inflation Pressure............................................................................................................31

WHEELS ................................................................................................................ 32

MAINTENANCE......................................................................................................... 33

SERVICE INTERVALS .......................................................................................... 33

LUBRICANTS, FUEL AND COOLANT .................................................................. 37

PERIODIC SERVICE................................................................................................. 41

HOW TO OPEN THE HOOD ................................................................................. 41

DAILY CHECK ....................................................................................................... 41

Checking Engine Oil Level..............................................................................................42

Checking Amount of Fuel and Refueling ........................................................................ 43

Checking and Cleaning Radiator and Screen to Prevent Overheating...........................44

Checking Tire Pressure ..................................................................................................45

Checking Transmission Fluid Level................................................................................46

Checking Coolant Level.................................................................................................. 46

Lubricating All Grease Fittings........................................................................................ 47

Checking Movable Parts................................................................................................. 48

EVERY 25 HOURS ................................................................................................ 48

Cleaning Precleaner and Air Cleaner Paper Element .................................................... 48

EVERY 50 HOURS ................................................................................................ 49

Checking Engine Start System.......................................................................................49

Checking OPC System ...................................................................................................50

Checking PTO Control System....................................................................................... 50

Cleaning Air Cleaner Element ........................................................................................ 51

Checking Carbon Canister Air Filter ............................................................................... 52

Checking Gear Box Oil Level.......................................................................................... 53

Greasing .........................................................................................................................53

Oiling...............................................................................................................................54

Checking Battery Condition ............................................................................................ 57

CONTENTS

EVERY 100 HOURS .............................................................................................. 58

Replacing Air Cleaner Paper Element............................................................................58

Cleaning Engine Shroud Panel.......................................................................................59

Checking Fuel Lines, Fuel Vapor Lines and Fuel Filter..................................................59

Checking Brake ..............................................................................................................61

Checking Fan Drive Belt Tension ................................................................................... 61

EVERY 150 HOURS .............................................................................................. 62

Changing Gear Box Oil................................................................................................... 62

EVERY 200 HOURS .............................................................................................. 63

Replacing Engine Oil Filter Cartridge .............................................................................63

Changing Engine Oil....................................................................................................... 64

Replacing Transmission Oil Filter Cartridge ...................................................................65

Checking Radiator Hose and Clamp ..............................................................................66

Checking Hydraulic Hose ...............................................................................................66

Adjusting Front Axle Pivot...............................................................................................68

Checking Spark Plug Condition & Gap........................................................................... 68

Cleaning Engine Shroud................................................................................................. 68

Checking Intake Air Line................................................................................................. 68

Replacing Fuel Filter....................................................................................................... 69

EVERY 400 HOURS .............................................................................................. 69

Changing Transmission Fluid ......................................................................................... 69

Cleaning Transmission Strainer......................................................................................70

Changing Front Axle Case Oil ........................................................................................ 70

Replacing Fuel Filter....................................................................................................... 71

EVERY 1500 HOURS ............................................................................................ 71

Checking Fuel Injection Nozzle (Injection Pressure) ......................................................71

EVERY 3000 HOURS ............................................................................................ 71

Checking Injection Pump................................................................................................71

EVERY 1 YEAR ..................................................................................................... 71

Replacing Air Cleaner Element.......................................................................................71

Flush Cooling System and Changing Coolant................................................................71

Anti-freeze ......................................................................................................................72

EVERY 2 YEARS................................................................................................... 73

Replacing Hydraulic Hose ..............................................................................................73

Replacing Fuel Lines and Fuel Vapor Lines...................................................................73

Replacing Engine Breather Hose ...................................................................................73

Replacing Radiator Hose................................................................................................73

Replacing Mower Gear Box Oil Seal .............................................................................. 73

Replacing Intake Air Line................................................................................................ 73

SERVICE AS REQUIRED...................................................................................... 73

Replacing Fuses.............................................................................................................73

Replacing bulbs .............................................................................................................. 74

Checking and Replacing Blade.......................................................................................74

Mower Belt Replacement................................................................................................76

Bleeding Fuel System..................................................................................................... 76

ADJUSTMENT........................................................................................................... 77

GENERAL TORQUE SPECIFICATION ................................................................. 77

TIGHTENING TORQUE CHART ........................................................................... 78

STORAGE ................................................................................................................. 79

TROUBLESHOOTING............................................................................................... 80

CONTENTS

ENGINE TROUBLESHOOTING ............................................................................ 80

BATTERY TROUBLESHOOTING ......................................................................... 80

MACHINE TROUBLESHOOTING ......................................................................... 81

MOWER TROUBLESHOOTING............................................................................ 82

INDEX........................................................................................................................ 83

-1SAFE OPERATION

SAFE OPERATION

Careful operation is your best insurance against an accident. Read and understand this section carefully before operation.
All operators, no matter how experienced they may be, should read this and other related manuals before operation of the
machine or any implement attached to it. It is the owner's obligation to instruct all operators in safe operation.
This cutting machine is capable of amputating hands and feet and throwing objects. Failure to observe the following safety
instructions could result in serious injury or death.

15.Keep your machine clean. Dirt, grease, and trash

1. BEFORE OPERATING

1. Know your equipment and its limitations. Read,
understand and follow all instructions in this manual
before attempting to start and operate the machine.

2. Know the controls and how to stop quickly.

3. Pay special attention to the safety labels on the
machine and mower.

4. The exhaust gas from the muffler is very hot. To
prevent fire, do not expose dry grass, mowed grass, oil
or any other combustible materials to exhaust gas.
Use a spark arrester where required. Also keep the
engine and muffler clean all the time.

5. Never wear loose, torn, or bulky clothing. It may catch
on moving parts or controls, leading to the risk of
accident. Safety boots or shoes, eye and hearing
protection, gloves, etc. are recommended.

6. Do not operate machine or any implement attached to
it while under the influence of alcohol, drugs, or other
substances or while fatigued.

7. Check brakes, and other mechanical parts for faulty
adjustment and wear. Replace worn or damaged parts
promptly. Check the tightness of all nuts and bolts
regularly. (For further details, see "MAINTENANCE"
section.)

8. Keep the machine and attachments in good operating
condition and keep safety devices in place and in
proper working condition.

9. This machine is equipped with many safety devices.
Do not attempt to remove or alter them.

10.Keep all shields and guards in place. Replace all
missing or damaged items for your safety.

11.Never allow any bystanders around or near machine
during operation.
Be sure the area is clear of other people before
mowing.
Stop machine if anyone enters the area.

12.Before allowing other people to use your machine,
explain proper operation to them and have them read
this manual before operation.

13.Never allow passengers or non-qualified operators on
the machine at any time. You must operate the
machine from the seat only.

14.Carefully check the area to be mowed and clear any
objects such as rocks, bottles, cans, toys, etc., that
may damage the mower, the grass catcher or cause
personal injury.

accumulations contribute to fires or lead to personal
injury.

16.Keep all nuts, bolts, and screws tight to be sure the
equipment is in safe working condition.
Check the mower blade mounting bolts for proper
tightness at frequent intervals.

17.Use only attachments recommended by KUBOTA.
Use proper ballast to front or rear of machine to reduce
the risk of upsets. Follow the "Safe Operation"
procedures, specified in the Equipment's Manual.

18.Follow the maintenance recommendations. See
"MAINTENANCE" section.

19.It is recommended that your machine be thoroughly
inspected at least once a year by an authorized
KUBOTA Dealer.

2. OPERATING

C Starting

1. Never start engine or operate levers from anywhere
other than the seat.

2. Before starting the engine, make sure that all levers
(including auxiliary control levers) are in their neutral
positions, that the parking brake is engaged, and that
both the mower clutch and the Power Take-Off (PTO)
are disengaged.

3. Do not start engine by shorting across starter
terminals or by by-passing the safety start switch. The
machine may start and move if normal starting circuitry
is bypassed.

4. Do not operate or idle engine in a poorly ventilated
area. Exhaust contains poisonous carbon monoxide, a
colorless and odorless gas.

C Working

1. Watch where you are going at all times. Watch for and
avoid obstacles. Be alert near trees and other
obstructions.

2. When working in groups, always let others know what
you are doing ahead of time.

3. Never try to get on or off a moving machine.

4. When using any attachments, never direct discharge
material toward bystanders. Do not allow anyone near
the attachments while in operation.
Do not mow when bystanders are present in the
mowing area.

SAFE OPERATION-2

5. To reduce fire hazards, keep the engine exhaust area
free of grass or leaves.

6. Slow down before turning.

7. Turn off blades when not mowing.

8. Mow only in daylight.

9. Be sure rotating blades and engine are stopped and
the key is removed before placing hands or feet near
blades.

10.Shut the engine off and wait for all movement to stop
before unclogging chute.

11.Know what is behind you and disengage power to
mower before backing up. Do not mow while in reverse
unless absolutely necessary and only after
observation of the entire area behind the mower.

12.Know what is behind you before overriding the KRA
system. Do not override the KRA system unless
absolutely necessary and safe to do so.
KUBOTA strongly recommends against overriding the
KRA system.

13.When mowing for the first time, cut the grass higher
than desired.
This will uncover any unseen object that may damage
the mower or grass catcher.

14.Always inspect the mower and grass catcher after
striking any foreign object. This will insure that all
mower and grass catcher parts are safe and secure
and not damaged.
Repair or replace any damaged parts before re­starting.

15.Use only attachment recommended in this manual.
Use proper ballast to front or rear of machine to reduce
the risk of upsets. Follow the "SAFE OPERATION"
procedures specified in the manuals included with the
equipment.

16.Do not operate the mower without either the grass
container or the guard in place.
Be aware of the mower discharge direction and do not
point it at anyone.

17.Watch for traffic when operating near or crossing
roadways.

18.Never leave a running machine unattended.
Always turn off blades, set parking brake, stop engine,
and remove the key before dismounting.

19.Be extremely alert for all other traffic when operating
the mower and grass catcher near public roads or
highways.

20.Do not operate where machine could tip or slip.
Do not operate near ditches, holes, embankments, or
other terrain which may collapse under the machine's
weight. The risk of machine tip-over is increased when
the ground is loose or wet.

C Pulling loads

Use extra care when pulling loads to reduce the risk of
serious personal injury or death due to a machine tip-over.
a) Pull only from the hitch. Never attach loads to the axle
housing or any other point above hitch.
b) Limit loads to those you can safely control.
c) Do not turn sharply.
d) Use care when backing.
e) Use front ballast or wheel weights when suggested in
this Operator's Manual.

C Operation on slopes

Slopes are a major factor related to loss-of-control and tip­over accidents, which can result in severe injury or death.
All slopes require extra caution. If you cannot back up the
slope or if you feel uneasy on it, do not mow it.
A Do not lift the grass container on a slope.

DO

1. Slowly mow up and down slopes, not across, to avoid
machine tip-over. Stay off hills and slopes too steep for
safe operation. Do not make sudden changes in speed
or direction.

2. Avoid starting or stopping on a slope. If tires lose
traction, disengage the blades and proceed slowly
straight down the slope.

3. If the machine stops going uphill, disengage PTO and
back slowly down.

4. Reduce speed and exercise extreme caution on
slopes and in sharp turns to prevent tip-over or loss of
control.

5. Use special caution when changing direction on
slopes.

6. Remove obstacles such as rocks, tree limbs, etc.

7. Stay alert for holes in the terrain and other hidden
hazards. Keep away from drop-offs. Uneven terrain
could overturn the machine. Tall grass can hide
obstacles.

8. Follow KUBOTA's recommendations for wheel
weights or counterweights to improve stability.

9. The weight of grass in the grass container may
increase the possibility of tip over.

DO NOT 3. USING THE PTO

-3SAFE OPERATION

1. Do not turn on slopes unless necessary and then turn
slowly and gradually downhill, if possible.

2. Do not use the machine on steep inclines.

3. Do not mow near drop-offs, ditches, or embankments.
The machine could suddenly turn over if a wheel falls
over the edge of a cliff or ditch, or if an edge caves in.

4. Do not mow on wet grass. Reduced traction could
cause sliding.

5. Do not try to stabilize the machine by putting your foot
on the ground.

6. Do not stop or start suddenly when going uphill or
downhill.

7. Never "freewheel". Do not let the machine travel
downhill with HST pedal at neutral position.

8. Do not modify or alter the machine and protective
guards.

C Children

Tragic accidents can occur if the operator is not alert to
the presence of children. Children are attracted to the
machine and the mowing activity. Never assume that
children will remain where you last saw them.

1. Keep children out of the mowing area and under the
watchful care of another responsible adult.

2. Be alert and turn the machine off if children enter the
area.

3. Before and when backing, look behind and down for
small children.

4. Never carry children. They may fall off and be
seriously injured or interfere with safe machine
operation.

5. Never allow children to operate the machine, even
under adult supervision.

6. Use extra care when approaching blind corners,
shrubs, trees, or other obstructions that might hide
children from sight.

C Operators, age 60 years and above

Data indicates that operators, age 60 years and above,
are involved in a large percentage of machine-related
injuries. These operators should evaluate their ability to
operate the machine safely enough to protect themselves
and others from serious injury.

C Stopping

1. Make sure that the machine has come to a complete
stop before dismounting.

2. Before dismounting, disengage the PTO, lower all
implements, place all control levers in their neutral
positions, apply parking brake, turn off the engine and
remove the key.

3. Do not park the machine on a steep incline. Park on a
flat level surface.

1. Before installing or using PTO-driven equipment, read
the manufacturer's manual and review the safety
labels attached to the equipment.

2. Wait until all moving components have completely
stopped before connecting, disconnecting, adjusting,
cleaning, or servicing any PTO-driven equipment.

3. Use the PTO with KUBOTA approved attachments.

4. USING THE LIFT LINK

1. Use lift link only with KUBOTA authorized attachments
designed for lift link usage.

5. TRANSPORTING

1. Disengage power to attachment(s) when transporting
or not in use.

2. Do not tow this machine. Use a suitable truck or trailer
when transporting on public roads.

3. It is recommended that this machine not be used on
public roads.

4. Use extra care when loading or unloading the machine
into a trailer or truck.

6. SERVICING

1. Before servicing the machine, park the machine on a
firm, level surface, set the parking brake, stop the
engine and remove the key.

2. Securely support machine or any machine elements
with stands or suitable blocking before working
underneath. For your safety do not rely on
hydraulically supported devices, they may leak down,
suddenly drop or be accidently lowered.

3. To avoid injury, do not adjust, unclog or service the
mower or grass catcher with the engine running. Make
sure rotating blades are stopped before dismounting
the machine.

4. Disengage power to attachment(s), stop the engine
and remove the key before making any repairs or
adjustments.

5. Allow the machine to cool off before servicing the
engine, muffler, etc.

6. Keep machine free of grass, leaves, or other debris
build-up.

7. Use extra care in handling gasoline and diesel fuels.
They are flammable and vapor is explosive.
(1) Use only an approved container.
(2) Do not remove fuel cap or refuel with the engine

running. Allow engine to cool before refueling. Do
not smoke while refueling or when standing near
fuel.

SAFE OPERATION-4

(3) Do not refuel the machine indoors and always

clean up spilled fuel or oil.

(4) Do not store the machine or fuel container inside

where there is an open flame, such as in a water
heater.

8. Do not change the engine governor setting or
overspeed the engine.

9. Never run a machine inside a closed area.

10.Mower blades are sharp and can cut your hands. Wrap
the blade(s) or wear gloves, and use extra caution
when servicing them.

11.Keep nuts and bolts, especially blade attachment
bolts, tight and keep equipment in good condition.

12.Do not smoke when working around the battery.
Keep all sparks and flames away from battery. The
battery presents an explosion hazard because it gives
off hydrogen and oxygen...especially when
recharging.

13.Before "JUMP STARTING" a dead battery, read and
follow all of the instructions to help protect the
alternator from damage due to extreme load changes.
(See "JUMP STARTING" in "OPERATING THE
ENGINE" section.)
Batteries contain sulfuric acid and produce explosive
gases. Follow the instructions below to prevent
personal injury.

A Wear eye and skin protection.
A Keep sparks and flame away.
A Always have adequate ventilation while charging

or using the battery.

14.Keep first aid kit and fire extinguisher available at all
times.

15.Disconnect the battery's negative (-) cable before
working on or near electric components.

16.Do not use or charge the refillable type battery if the
fluid level is below the LOWER (lower limit level) mark.
Otherwise, the battery component parts may
prematurely deteriorate, which may shorten the
battery's service life or cause an explosion. Check the
fluid level regularly and add distilled water as required
so that the fluid level is between the UPPER and
LOWER levels.

17.To avoid sparks from an accidental short circuit,
always disconnect the battery's negative (-) cable first
and connect it last.

(1) Battery
(2) Positive cable (+)
(3) Negative cable (-)

18.Make sure cir-clips, nuts and spring lock washers are
properly secured on the front and rear wheels,
respectively.

19.Never tamper with safety devices.
Check their proper operation regularly.

20.Check brake operation frequently. Adjust and service
as required.

21.Properly dispose of used lubricants, filters, batteries,
and other such components.

22.Do not attempt to mount a tire on a rim. This should be
done by a qualified person with the proper equipment.

23.Always maintain the correct tire inflation pressure. Do
not inflate tires above the recommended pressure
shown in the Operator's Manual.

24.Securely support the machine when changing wheels.

25.Make sure that wheel bolts have been tightened to the
specified torque.

26.Escaping hydraulic fluid under pressure has sufficient
force to penetrate the skin causing serious personal
injury. Before disconnecting lines, be sure to relieve all
pressure. Before applying pressure to the system,
make sure all connections are tight and that lines,
pipes, and hoses are not damaged.

27.Fluid escaping from pinholes may be invisible. Use a
piece of cardboard or wood to search for suspected
leaks: do not use hands. Use safety goggles or other
eye protection.
If injured by escaping fluid, see a medical doctor at
once. Serious infection or reaction will result if proper
medical treatment is not administered immediately.
This fluid can produce gangrene or severe allergic
reaction.

-5SAFE OPERATION

7. STORAGE

1. Keep the machine and supply of fuel in locked storage
and remove the key to prevent children or others from
playing or tampering with them.

2. When machine is to be stored for a long time,
disconnect battery cables or remove the battery.
Always remove the negative (-) cable first and reinstall
the negative (-) cable last.

3. Do not store the machine with fuel in the tank inside a
building where fumes may ignite. Allow the engine to
cool before storing.

4. To avoid the danger of exhaust fume poisoning, do not
operate the engine in a closed building without
adequate ventilation.

5. To reduce fire hazards, clean the machine thoroughly
before storage. Dry grass and leaves around the
engine and mufflers may ignite.

6. Moisture content in most grasses can damage the
mower and grass catcher if these components are not
properly cleaned after use. Also, dry grass and leaves
left in the container can be a fire hazard. Always make
sure the container and the duct are clean and
completely empty before storage.

(1) Cardboard
(2) Hydraulic line
(3) Magnifying glass

28.Waste products such as used oil, fuel, hydraulic fluid,
and batteries, can harm the environment, people, pets
and wildlife. Please dispose properly.

29.Do not use beverage containers for waste fluids or
other products. Someone, particularly children, may
drink them by mistake.

30.See your local Recycling Center or KUBOTA Dealer to
learn how to recycle or get rid of waste products.
A A Material Safety Data Sheet (MSDS) provides

specific details on chemical products; physical and
health hazards, safety procedures, and emergency
response techniques. The seller of the chemical
products used with your machine is responsible for
providing the MSDS for that product upon request.

SAFE OPERATION-6

8. DANGER, WARNING AND CAUTION LABELS

-7SAFE OPERATION

SAFE OPERATION-8

-9SAFE OPERATION

SAFE OPERATION-10

9. CARE OF DANGER, WARNING AND CAUTION LABELS

1. Keep danger, warning and caution labels clean and free from obstructing material.

2. Clean danger, warning and caution labels with soap and water, dry with soft cloth.

3. Replace damaged or missing danger, warning and caution labels with new labels from your local KUBOTA Dealer.

4. If a component with danger, warning and caution label(s) affixed is replaced with new parts, make sure new label(s) is
(are) attached in the same location(s) as the replaced component.

5. Mount new danger, warning and caution labels by applying on a clean dry surface and pressing any bubbles to outside
edge.

1SERVICING OF LAWN AND GARDEN TRACTOR

SERVICING OF LAWN AND GARDEN TRACTOR

After reading this manual thoroughly, you will find that you
can do some of the regular maintenance yourself. Your
dealer is interested in helping you get the best
performance from your new machine and wants to help
you get the most value from it. When in need of parts or
major service, be sure to see your KUBOTA Dealer. When
in need of parts, be prepared to give your dealer the
machine, engine and mower serial numbers.
Locate the serial numbers now and record them in the
space provided.

Type Serial No.

Machine

Engine

Mower

Date of Purchase

Name of Dealer

(To be filled in by purchaser)

C Warranty

This machine is warranted under the Kubota Limited
Express warranty a copy of which may be obtained from
your selling dealer. No warranty shall, however, apply if
the machine has not been handled according to the
instruction given in the Operator's Manual even it is within
the warranty period.

C Scrapping the machine and its procedure

To put the machine out of service, correctly follow the
local rules and regulations of the country or territory where
you scrap it. If you have questions, consult your local
KUBOTA Dealer.

(1) Engine serial No.

(1) Machine serial No.
(2) Mower serial No.

(1) Engine serial No.

2 SPECIFICATIONS

SPECIFICATIONS

Model GR2020G GR2120 GR2120AU

Model GH630 D782

Type Air-cooled Gasoline Liquid-cooled Diesel

Total displacement cm (cu. in.) 624 (38.1) 778 (47.5)

Gross power kW (HP) 15.3 (20.5)*1 15.6 (21)*1

Rated revolution rpm --- 3000

Low idling revolution rpm --- 1200 to 1350

Engine

Capacity

Machine

No. of cylinders 2 3

Starter Electric starter with battery

Battery 10U1L (12V, 300CCA) 51R (12V, 475CCA)

Fuel

Preheating system --- Super glow

Engine stop Key stop

Fuel tank L (U.S.gals.) 16 (4.2) 18 (4.8)

Engine oil L (U.S.qts.) 1.9 (2.0) 2.8 (3.0)

Radiator coolant L (U.S.qts.) --- 2.1 (2.2)

Hydrostatic transmission oil L (U.S.qts.) 3.3 (3.5)

PTO Shaft drive

PTO clutch Hydraulic Wet Multi Discs

PTO brake Wet Multi Discs

Front

Tires

Rear

Steering type Full hydraulic power steering (Glide steer)

Brake Internal expanding brake

Travel speed control Foot pedal

Transmission Hydrostatic

Traveling
speeds

Forward km/h (mph) 0 to 10 (0 to 6.2)

Reverse km/h (mph) 0 to 5 (0 to 3.1)

Size 16 x 7.50 - 8

Type Turf, Bar Turf, Bar Turf

Size 23 x 10.50 - 12

Type Turf, Bar Turf, Bar Turf

Automobile unleaded

or regular gasoline

Gasohol*2

MTBE*2

Diesel fuel No.1 (below -10 )
Diesel fuel No.2 (above -10 )

Model GR2020G GR2120 GR2120AU

Overall length mm (in.) 1990 (78.3)

Overall width with mower deck mm (in.) 1550 (61.0) 1550 (61.0) 1700 (66.9) 1550 (61.0)

Overall height mm (in.) 1290 (50.8)

Dimensions

Mower deck Model RCK48GR RCK48GR RCK54GR RCK48GR

Grass catcher Opt. Opt. ---

Wheel base mm (in.) 1280 (50.4)

Front mm (in.) 825 (32.5)

Tread

Rear mm (in.) 820 (32.3)

Weight with mower deck kg (lbs) 400 (882) 435 (959) 440 (970) 435 (959)

Model RCK48GR RCK54GR

Cutting width mm (in.) 1219 (48.0) 1372 (54.0)

Cutting height mm (in.) 25 to 102 (1.0 to 4.0)

3SPECIFICATIONS

Adjustment of cutting height Dial gauge

Mounting method Quick joint, Parallel linkage

Weight (Approx.) kg (lbs) 75 (165.3) 80 (176.4)

Mower

Total length mm (in.) 900 (35.4) 905 (35.6)

Dimensions

Total width mm (in.) 1550 (61.0) 1700 (66.9)

Total height mm (in.) 290 (11.4)

Discharge direction RIGHT

Gear box oil L (U.S.qts.) 0.15 (0.16)

NOTE: *1 Manufacturer's estimate The company reserves the right to change the specifications without notice.
*2 Gasohol (up to 10% ethyl alcohol, 90% unleaded gasoline by volume) or Methyl Tertiary Butyl Ether (MTBE) and
unleaded gasoline blends (up to a maximum of 15% MTBE by volume) are approved for the engine. Other
gasoline/alcohol blends are not approved.

4 IMPLEMENT LIMITATIONS

IMPLEMENT LIMITATIONS

The KUBOTA Machine has been thoroughly tested for proper performance with implements sold or approved by KUBOTA.
Use of implements which exceed the maximum loading weight listed below, or which are not recommended for use with
the KUBOTA Machine may result in malfunctions or failures of the machine, damage to other property and injury to the
operator or others. (Any malfunctions or failures of the machine resulting from use with improper implements are not
covered by the warranty.)

Maximum axle loading weight

MODEL Front axle Wf Rear axle Wr Total gross vehicle weight

GR2020G

GR2120

GR2120AU

300 kg (661 lbs) 500 kg (1102 lbs) 700 kg (1543 lbs)

B Ballast

To avoid serious injury:
A Additional ballast will be needed for operating

specific attachments. When the attachment is
raised, drive slowly over rough ground,
regardless of how much ballast is used.

A Add front ballast to increase front end stability

and help prevent possible front end tip up.

A Always back up when going up a slope. Driving

forward could cause the machine to tip over
backward. Stay off hills and slopes too steep
for safe operation.

Front ballast is added for stability and steering control
when heavy rear mounted equipment is installed.
Front ballast also compensates for weight transferred to
the rear wheels by the draft of towed implements through
the hitch.
Add additional front ballast, if necessary, for stability and
safety during transport of heavy rear mounted equipment.
Front end ballast may not always maintain the required
stability if the machine is driven too fast over rough ground
with heavy rear mounted equipment in the raised position.
Use care and drive slowly under these conditions.
Limit ballast to machine operating capacity. Be sure to
remove ballast when it is not needed.
Add ballast to rear end if needed for stability. Heavy front
mounted attachments tend to lift rear wheels. Add enough
ballast to maintain steering control and prevent tipover.
The Attachment's Manual shows how much rear ballast is
required for your application. Rear ballast are available
from your KUBOTA Dealer.

5IMPLEMENT LIMITATIONS

6 INSTRUMENT PANEL AND CONTROLS

INSTRUMENT PANEL AND CONTROLS

(1) Easy checker(TM)....................................... 21

(2) Choke lever (GR2020G)............................. 13

(3) Throttle lever............................................... 19

(4) Head light switch......................................... 18

(5) Parking brake pedal.................................... 19

(6) PTO lever.................................................... 28

(7) Hydraulic lift lever........................................ 19

(8) Hour meter.................................................. 22

(9) Cruise control knob..................................... 20

(10) KRA system override switch..................... 28

(11) Key switch................................................. 12

(12) Brake pedal............................................... 11

(13) Speed control pedal.................................. 20

MOWER MOUNTING

ATTACHING THE MOWER

To avoid serious injury:
A Shut off the engine and remove the key before

attaching the mower.

BMounting the Mower Deck

1. Park the machine on level ground and place the
mower deck at the left side of the machine.

2. Set the front anti-scalp rollers at the topmost position.
Turn the front wheel to the right.

3. Pull the hydraulic lift lever to raise rear links.

4. Adjust the height control dial to "1". Slide the mower
deck under the machine, and then return wheels to
straight ahead position.

(1) Hydraulic lift lever
(2) Mower's rear link

6. Release the L pins lock to attach the rear links to the
mower deck.

7MOWER MOUNTING

(A) "RIGHT"

5. Place the hydraulic lift lever in the "DOWN" position.
Push down the rear links to align with the mower
bracket.

(1) Mower's rear link
(2) L pin

7. Attach the front links to the front roller brackets.

MOWER MOUNTING8

(1) Front link
(2) Front roller bracket

A Adjust the length (L) of the front link.

(See "ADJUSTING THE PARALLEL LINKAGE" in
"MOWER MOUNTING" section.)

8. Pull the lever fulcrum fixing pin and turn it counter
clockwise to lock.

9. Hook and raise the front link with the link fixing lever,
and then lay the link fixing lever onto the front bracket
of the machine.

10.Turn the lever fulcrum fixing pin clockwise and push it
into position to fix the link fixing lever.

(1) Link fixing lever
(2) Lever fulcrum fixing pin
(3) Front link
(4) Front bracket

(1) Universal joint
(2) Coupler

(A) "TUG"

A For dismounting the mower deck, reverse the above

procedures.

11.Pull back the coupler of the universal joint.
Push the universal joint into the PTO shaft until the
coupler locks.
Tug the universal joint backward and forward to make
sure it is locked securely.

9MOWER MOUNTING

ADJUSTING THE PARALLEL LINKAGE

ADJUSTING THE MOWER DECK (SIDE TO
SIDE)

To avoid serious injury:

A Shut off the engine and remove the key.
A Set parking brake.
A Allow the blades to stop before making

adjustments.

A Blades may be sharp, when you handle blades,

wear heavy gloves or wrap end of blade with a
rag.

1. Park the machine on a level surface.

2. Make sure the mower blades are level. Then tighten
the lock nuts securely.
Adjust (L) of front links with lock nut so that A is 0 to 5
mm (0 to 0.2 in.).
A = (Y) - (X)

To avoid serious injury:

A Shut off the engine and remove the key.
A Set parking brake.
A Allow the blades to stop before making

adjustments.

A Blades may be sharp. When you handle blades,

wear heavy gloves or wrap end of blade with a
rag.

1. Park the machine on a level surface.

2. Tire inflation pressure must be correct.
(See "TIRE AND WHEELS" section.)

3. Raise the hydraulic lift lever to the top position.

4. Turn the cutting height control dial to adjust height to
the desired height.

5. Lower the mower deck by pushing the hydraulic lift
lever forward.

6. Turn the left blade so that it is parallel to rear axle. Hold
drive belt and the turn right blade so that it is parallel
to axle.

7. Measure from each outside blade tip (L) and (R) to the
level surface. The difference between measurements
should be less than 3 mm (0.1 in.).

(1) Lock nut

(H) Blade tip height

MOWER MOUNTING10

8. Loosen the locknut at both sides of the machine.
Adjust the cutting height fine tuning bolts so that the
difference between measurements (L) and (R) is less
than 3 mm (0.1 in.).

9. Lock the nuts.

(1) Lift link
(2) Cutting height fine tuning bolt
(3) Lock nut

ADJUSTING THE MOWER LIFT STOPPERS

The mower lift stoppers are designed for maintaining the
balance of the mower deck, when lifting the mower to the
highest position. Make sure that the stoppers are in
contact with the underside of the frame.
To adjust:

1. Lift the mower to the highest position.

2. Loosen the lock nuts and adjust the stoppers on both
sides so that the bolt heads are in contact with the
underside of the frame.

3. Lower the mower deck.

4. Turn the stoppers counterclockwise a half turn, and
then secure the lock nuts.

(1) Mower lift stopper
(2) Lock nut

DISMOUNTING THE MOWER DECK

For dismounting the mower deck, reverse the above
procedures.

OPERATING THE ENGINE

To avoid serious injury:
A Read "SAFE OPERATION" in the front of this

manual.

A Read the danger, warning and caution labels

located on the machine.

A To avoid danger of exhaust fume poisoning, do

not operate the engine in a closed building
without proper ventilation.

A Never start the engine while standing on the

ground. Start the engine only from the
operator's seat.

STARTING THE ENGINE

1. Sit on the operator's seat.

11OPERATING THE ENGINE

2. Apply the parking brake.

To apply the parking brake:

Depress the brake pedal firmly with your right foot and the
parking brake pedal simultaneously with your left foot.
Then release the brake pedal while holding the parking
brake pedal down.

To release the parking brake:

Depress the brake pedal and release slowly.

(1) Brake
(2) Parking brake

3. Make sure that the PTO lever is in the
"DISENGAGED" position.

(1) Brake pedal
(2) Parking brake pedal

(A) "DEPRESS"

(1) PTO lever : "ENGAGED"

: "DISENGAGED"

OPERATING THE ENGINE12

4. Set the throttle lever 1/2 way forward.

(1) Throttle lever : "FAST"

: "SLOW"

5. Insert the key into the key switch and
turn clockwise 1 notch.
Make sure the easy checker lights are
ON.

BKey Switch

[GR2020G]

OFF............ The position where the key can be

inserted into or removed from the
key switch. [When the key is turned
to this position, the engine shuts off.]

ON..............

START........ Apply the parking brake and turn the

The engine keeps running.

key switch to this position to start the
engine.

: "OFF"
: "ON"

A Do not use starting fluid or ether.
A To protect the battery and the starter, make sure that

the starter is not continuously turned for more than 10
seconds at a time.
If the engine does not start, allow 60-second cool
down period between starting attempts.

A If the starter does not turn the engine over, shut off the

starter immediately. Do not make further attempts to
start the engine until the condition is corrected. Do not
jump start using another battery.
Consult your local KUBOTA dealer.

A Do not turn the key switch to the "START" position

while the engine is running.

A When the temperature is below 0 (32 ), run the

engine at medium speed to warm up the lubricant of
the engine and the transmission for at least 10
minutes. If the machine is operated before the
lubricant is warm enough, the machine life will be
shortened.

A Do not operate the machine under full load until it is

sufficiently warmed up 2 or 3 minutes for temperature
above 0 (32 ).

A When the ambient temperature is less than -15

(5 ), remove the battery from the machine and store
it somewhere warm until the next operation.

: "START"

13OPERATING THE ENGINE

[GR2120, GR2120AU]

OFF............ The position where the key can be

inserted into or removed from the
key switch. [When the key is turned
to this position, the engine shuts off.]

ON..............

PREHEAT...

START........ Apply the parking brake and turn the

The engine keeps running.

The super glow plug is heated.

key switch to this position to start the
engine.

6. [GR2120, GR2120AU]
Turn the key switch to the "PREHEAT"
position clockwise, and hold it for about
5 seconds.
For the appropriate preheating time,
refer to the table below:

Temperature Preheating Time

Over 0 (32 ) 5 sec.

Below 0 (32 ) 10 sec.

BThrottle Lever and Choke Lever

Pulling the throttle lever downward decreases the engine
speed and pushing it upward increases the engine speed.

: "OFF"
: "ON"

A Do not turn the key switch to the "START" position

while the engine is running.

A When the temperature is below 0 (32 ), run the

engine at medium speed to warm up the lubricant of
the engine and the transmission for at least 10
minutes. If the machine is operated before the
lubricant is warm enough, the machine life will be
shortened.

A Do not operate the machine under full load until it is

sufficiently warmed.

A Do not use starting fluid or ether.
A When the ambient temperature is less than -15

(5 ), remove the battery from the machine and store
it somewhere warm until the next operation.

: "PREHEAT"
: "START"

(1) Throttle lever : "FAST"

: "SLOW"

[GR2020G]
C Choke lever
[For a Cold Engine]

Always pull the choke knob out to the "ON" position to
start the engine in cold conditions.

Gradually return the choke control to the "OFF" position
after the engine starts and warms up.

The engine/equipment may be operated during the warm­up period, but it may be necessary to leave the choke
partially on until the engine warms up.

[For a Warm Engine]

Always push the choke knob in to the "OFF" position after
the engine starts.

OPERATING THE ENGINE14

7. Turn the key switch to the "START"
position and release the key to the "ON"
position when the engine starts.

BCold Weather Starting

[GR2020G]

If the ambient temperature is below 0 (32 ) and the
engine is very cold, start it in the following manner:

1. Pull the choke knob out.

2. Turn the key switch to the "START" (" ") position.

A Operate the starter 5 seconds.
A If the engine does not start, wait 10 seconds.
A Repeat this procedure until the engine starts.

3. When the engine starts, release the key to the "ON"
(" ") position.

4. Place the throttle lever midway between the "SLOW"
and the "FAST" positions.

[GR2120, GR2120AU]

When the ambient temperature is below -5 (23 ) and
the engine is very cold. (If the engine fails to start after 10
seconds, turn off the key for 30 seconds. Then repeat
steps 6 and 7. To protect the battery and the starter, make
sure that the starter is not continuously turned for more
than 30 seconds.)

STOPPING THE ENGINE

[GR2020G]

1. After slowing the engine to half speed, turn the key
switch to the "OFF" position.

2. Remove the key.

3. Do not leave the key switch "ON" (key in the "ON"
position) as the battery will discharge when the engine
is not running.

4. Apply the parking brake.

5. Close the fuel cock.

(1) Fuel cock (A) "OPEN"

(B) "CLOSE"

BBlock Heater (Option)

A block heater is available as an option from your local
dealer. It will assist you in starting your machine when the
ambient temperature is below -15 (5 ).

8. Check to see that all the lamps on the
Easy Checker(TM) are "OFF".

If the lamp is still on, immediately stop the engine and
determine the cause.

9. Warm the engine by running at medium
speed.

A Do not stop the engine when the machine is on an

incline for a long time. The engine oil may go into the
carburetor and the muffler through the valve system.

A Place the throttle lever in the half speed position to

help prevent the engine from backfiring before
stopping the engine.

[GR2120, GR2120AU]

1. After slowing the engine to idle, turn the key switch to
the "OFF" position.

2. Remove the key.

3. Do not leave the key switch "ON" (key in the "ON"
position) as the battery will discharge when the engine
is not running.

4. Set the parking brake.

15OPERATING THE ENGINE

BEngine Stop (By manual)

[GR2020G]

The engine stops when the key switch is turned off. If the
engine does not stop, make sure the speed control pedal
are in neutral position, the PTO lever is "OFF", the mower
is lowered to the ground and the parking brake is set, and
then carefully get off the machine. Open the hood, close
the fuel cock and wait the engine stops. Then contact your
local KUBOTA Dealer immediately.

To avoid serious injury:
A Do not operate the machine until the engine

stop system is repaired.

WARMING UP

To avoid serious injury:
A Be sure to apply the parking brake during

warm-up.

For 5 minutes after engine start-up, allow engine to warm
up without applying any load. This is to allow oil to reach
every engine part. If load should be applied to the engine
without this warm-up period, trouble such as seizure,
breakage or premature wear may develop.

BWarm-up and Transmission Oil in the Low

Temperature Range

Hydraulic oil serves as transmission fluid. In cold weather,
the oil may be cold with increased viscosity. This can
cause delayed oil circulation or abnormally low hydraulic
pressure for some time after engine start-up. This in turn
can result in trouble in the hydraulic system or a damage
to the hydraulic clutch.
To prevent the above, observe the following instructions:
Warm up the engine at about 50% of rated rpm according
to the table below:

Atmospheric temperature

Warm-up time

requirement Higher

Higher than 0 (32 ) Approx. 5 minutes

-10 to 0 (14 to 32 ) 5 to 10 minutes

-20 to -10 (-4 to 14 ) 10 to 15 minutes

Below -20 (-4 ) More than 15 minutes

A Do not operate unless the engine is well warmed up. If

operation is attempted while the engine is still cold, the
hydraulic mechanism will not function properly and its
service life will be shortened.

A If noises are heard after the hydraulic control lever has

been activated and the implement is lifting, the
hydraulic mechanism is not adjusted properly. Unless
corrected, the unit will be damaged. Contact your local
KUBOTA Dealer for adjustment.

OPERATING THE ENGINE16

JUMP STARTING

To avoid serious injury:
A Keep cigarettes, sparks, and flames away from

battery.

A If machine battery is frozen, do not jump start

engine.

A Do not connect other end of negative (-) jumper

cable to negative (-) terminal of machine
battery.

When jump starting engine, follow the instructions below
to safely start the engine.

1. Bring helper vehicle with a battery of the same voltage
as disabled machine within easy cable reach. "THE
VEHICLES MUST NOT TOUCH".

2. Apply the parking brakes of both vehicles and put the
shift levers in neutral. Shut the engine off.

3. Put on safety goggles and rubber gloves.

4. Ensure the vent caps are securely in place.
(if equipped)

5. Attach the red clamp to the positive (red, (+) or pos.)
terminal of the dead battery and clamp the other end
of the same cable to the positive (red, (+) or pos.)
terminal of the helper battery.

6. Clamp the other cable to the negative (black, (-) or
neg.) terminal of the helper battery.

7. Clamp the other end to the engine block or frame of
the disabled machine as far from the dead battery as
possible.

8. Start the helper vehicle and let its engine run for a few
moments. Start the disabled machine.

9. Disconnect the jumper cables in the exact reverse
order of attachment. (Steps 7, 6 and 5).

A This machine has a 12 volt negative (-) ground starting

system.

A Use only same voltage for jump starting.
A Use of a higher voltage source on machine could

result in severe damage to machine electrical system.
Use only matching voltage source when "Jump
starting" a low or dead battery condition.

HIGH ALTITUDE OPERATION

[GR2020G]

Operating the engine with the wrong engine configuration
at a given altitude may increase its emissions and
decrease fuel efficiency and performance.
To ensure correct engine operation at altitudes above
1219 meters (4000 ft.), it may be necessary to have an
authorized KUBOTA dealer install a special high-altitude
jet kit in the carburetor. If a high-altitude kit has been
installed, the engine must be reconverted to the original
jet size, before it is operated at lower altitudes, or
overheating and engine damage can result.

(1) Dead battery
(2) Jumper cables
(3) Engine block or frame
(4) Helper battery

Connect cables in numerical order.
Disconnect in reverse order after use.

OPERATING THE MACHINE

OPERATING NEW MACHINE

How a new machine is operated and maintained
determines the life of the machine.
A new machine just off the factory production line has
been tested, but the various parts are not accustomed to
each other, so care should be taken to operate the
machine for the first 50 hours at a slower speed and avoid
excessive work or operation until the various parts
become "broken-in." The manner in which the machine is
handled during the "breaking-in" period greatly affects the
life of your machine. Therefore, to obtain the maximum
performance and the longest life of the machine, it is very
important to properly break-in your machine. In handling a
new machine, the following precautions should be
observed.

BChanging Lubricating Oil for New

Machines

The lubricating oil is especially important in the case of a
new machine. The various parts are not "broken-in" and
are not accustomed to each other; small metal grit may
develop during the operation of the machine; and this may
wear out or damage the parts. Therefore, care should be
taken to change the lubricating oil a little earlier than
would ordinarily be required.
For further details of change interval hours, see
"SERVICE INTERVALS" in "MAINTENANCE" section.

BEngine Break-in

After the first 50 hours of operation, change the engine oil
and filter. (See "EVERY 100 HOURS" and "EVERY 200
HOURS" in "PERIODIC SERVICE" section.)

To avoid serious injury or death:
A Do not operate the mower without the deflector

shield in the down position.

To avoid serious injury:
A Do not allow any person other than the driver to

ride on the machine.

A Do not drive the machine close to the edges of

ditches or banks which may collapse under the
weight of the machine, especially when the
ground is loose or wet.

A Slow down before turning.
A To avoid tip over, operate up and down slopes,

not across. Avoid sudden starts and stops on
slopes. Slow down, and use extra caution when
changing direction on a slope. Do not use the
machine on a steep incline.
Park the machine on a firm, level surface.

A Watch where you are going at all times. Watch

for and avoid obstacles. Be alert at curbs, near
trees, and other obstructions and hidden
hazards.

A Do not drive a machine on streets or highways.

Watch for traffic when you cross roads or
operate near roads.

A Look to the rear before and when backing.

Make sure the area immediately behind you is
clear of obstructions or holes and small
children. Use extra caution when a machine is
equipped with Grass Catcher.

17OPERATING THE MACHINE

BMachine Break-in

After the first 200 hours of operation, change the
transmission fluid.
After the first 50 hours of operation, change the oil filter
cartridge. (See "EVERY 200 HOURS" in "PERIODIC
SERVICE" section.)

To avoid serious injury:
A Clear the work area of objects which might be

picked up and thrown by blades.

A Do not direct the opening of the chute at

bystanders or animals. Ejected objects may
cause injury. Plan your mowing carefully
before starting operation.

A Keep bystanders especially children and

animals away from the mowing area.

A Be sure to disengage the PTO and sit on the

operator's seat before starting the engine.

OPERATING THE MACHINE18

STARTING

1. Adjust the operator's position.

BOperator's Seat

To avoid serious injury:
A Make sure that the seat is completely secured

after each adjustment.

A Do not allow any person other than the

operator to ride on the machine.

C Travel adjustment

The operator's seat position can be adjusted forward and
backward by 150 mm (6 in.) range by pulling the seat
sliding lever.

C Suspension adjustment

Turn the suspension adjust knob to achieve the optimum
suspension setting.

(1) Suspension adjust knob (A) To decrease tension

(B) To increase tension

2. Select Light Switch Positions

(1) Seat sliding lever

A After adjusting the operator's seat, be sure to check

that the seat is properly locked.

BHead Light Switch

(A)......Head lights ON.

(B)......Head lights OFF.

(1) Head light switch

19OPERATING THE MACHINE

3. Raise the implement.

BHydraulic Lift Lever

The hydraulic lift lever is used to raise and lower
implement used with the machine (ex. Mower).
To lower implement, push the lever FORWARD.
To raise it, pull the lever BACKWARD.

(1) Hydraulic lift lever : "DOWN"

N: "NEUTRAL"

: "UP"

4. Accelerate the Engine.

BThrottle Lever

Pulling the throttle lever backward decreases the engine
speed and pushing it forward increases the engine speed.

(1) Throttle lever : "FAST"

: "SLOW"

5. Unlock the Parking Brake.

A Do not operate until the engine is warmed up. If

operation is attempted when the engine is still cold, the
hydraulic system may be damaged.

A Do not operate at slow Engine rpm. Move the throttle

lever above 1/2.

A If noises are heard when implement is lifting after the

hydraulic lift lever has been activated, the hydraulic
mechanism is not adjusted properly. Contact your
local KUBOTA Dealer for adjustment.

BParking Brake

To release the parking brake, depress the brake pedal
again.

(1) Brake pedal

OPERATING THE MACHINE20

6. Depress the Speed Control Pedal.

BSpeed Control Pedal

To avoid serious injury:
A Do not operate if the machine moves on a level

ground with foot off Speed Control Pedal.

"FORWARD" ( )
Depress the speed control pedal with the toe of your right
foot to move forward.

"REVERSE" ( )
Depress the speed control pedal with the heel of your right
foot to move in reverse.

Depress the speed control pedal a little and you can drive
slowly.
To increase travel-speed, depress the speed control
pedal more until the desired speed is reached.

A When the parking brake is applied, the speed control

pedal is locked in the "NEUTRAL" position.

BCruise Control Device

The cruise control device is designed for machine
operating efficiency and operator's comfort. This device
will provide a constant forward operating speed by
mechanically holding the speed control pedal at a
selected position.

C To engage cruise control device

1. Accelerate speed to desired level using speed control
pedal.

2. Pull the cruise control knob.

3. Release the speed control pedal while pulling the
cruise control knob.

4. Release the cruise control knob and desired speed will
be maintained.

C To disengage speed set device
A Step on the forward acceleration side of the pedal or

depress the brake pedal.

A Cruise control device will not operate in reverse.

A To prevent the damage of cruise control device, do not

depress the reverse pedal when the cruise control
device is engaged.

(1) Speed control pedal (A) "FORWARD"

(B) "REVERSE"

(1) Speed control pedal (A) "FORWARD"

(B) "REVERSE"

(1) Cruise control knob : "ENGAGED"

STOPPING

BStopping

1. Slow down the engine.

2. Step on the brake pedal.

3. After the machine has stopped, disengage the PTO,
lower the implement to the ground and set the parking
brake.

CHECK DURING DRIVING

BImmediately Stop the Engine if:

A The engine suddenly slows down or accelerates.
A Unusual noises are suddenly heard.
A Exhaust fumes suddenly become discolored.

While driving, make the following checks to see that all the
parts are functioning normally.

21OPERATING THE MACHINE

BEasy Checker (TM)

If the warning lamps in the Easy Checker(TM) come on
during operation, stop the engine immediately, and find
the cause as shown below.
Never operate the machine while Easy Checker(TM) lamp
is "ON".

: Engine oil pressure

If the oil pressure in the engine goes below the
prescribed level, the warning lamp in the Easy
Checker(TM) will come on.

If this should happen during operation, and it does
not go off when the engine is accelerated to more
than 1000 rpm, check the level of engine oil.

(See "Checking Engine Oil Level" in "DAILY CHECK"
in "PERIODIC SERVICE" section.)

: Electrical charge
If the alternator is not charging the battery, the warning
lamp in the Easy Checker(TM) will come on.

If this should happen during operation, check the
electrical charging system or consult your local
KUBOTA Dealer.

: Coolant temperature
If this warning light comes on during operation, take

the actions according to "Checking and Cleaning
Radiator to Prevent Overheating".

: Glow plug Indicator (Pre-heating Indicator)

When the key switch is in the "PREHEAT" position, the
glow plug indicator illuminates.

A For checking and servicing of your machine, consult

your local KUBOTA Dealer for instructions.

(1) Easy Checker(TM)

BEngine Overheating Precautions

If the coolant temperature warning light come on or the
buzzer sounds, take the following actions.

1. Stop machine operation in a safe place, disengage the
mower deck and keep the engine idling.

2. Don't stop the engine immediately; stop it after about
5 minutes of unloaded idling.

3. Shut off the engine and keep well away from the
machine for 10 minutes or while the steam is blown
out.

4. Checking that there is no danger of being burned, get
rid of the causes of overheating according to the
manual, see "TROUBLESHOOTING" section.
Start the engine again.

OPERATING THE MACHINE22

BFuel Gauge

The fuel gauge indicates the fuel level.
Be careful not to empty the fuel tank. Otherwise air may
enter the fuel system.
If this should happen, the fuel system should be bled.
(See "SERVICE AS REQUIRED" in "PERIODIC
SERVICE" section.)

(1) Fuel gauge (E) "EMPTY"

(F) "FULL"

BHourmeter

The hourmeter indicates in 5 digits the hours the machine
has been used; the last digit indicates 1/10 of an hour.

A As the hour meter works electrically, it starts to work

when the key switch is turned to "ON", regardless of
the engine running or not.

(1) Hours used

A Use proper fuel for your machine, or it damages the

machine.
GR2020G: Gasoline, Gasohol, MTBE
GR2120, GR2120AU: Diesel fuel
Gasohol (up to 10% ethyl alcohol, 90% unleaded
gasoline by volume) or Methyl Tertiary Butyl Ether
(MTBE) and unleaded gasoline blends (up to a
maximum of 15% MTBE by volume) are approved for
the engine. Other gasoline/alcohol blends are not
approved.

A Do not refuel over "F". Fill the tank only to the bottom

of the filler neck in the fuel tank.

23OPERATING THE MACHINE

PARKING

BParking

To avoid serious injury:
Before leaving the operator's position:

A Apply parking brake.
A Lower all implements to the ground.
A Shut off the engine.
A Remove the key.

1. When parking, be sure to set the parking brake.

To apply the parking brake;

Depress the brake pedal firmly with your right foot and
the parking brake pedal simultaneously with your left
foot. Then release the brake pedal while holding the
parking brake pedal down.

2. Before getting off the machine, disengage the PTO,
lower all implements to the ground, place all control
levers in their "NEUTRAL" positions, set the parking
brake, stop the engine and remove the key.

3. If it is necessary to park on an incline, be sure to chock
the wheels to prevent accidental rolling of the
machine.

TRANSPORTING

1. Transport the machine on a trailer.

A Fasten the machine to the trailer.
A To prevent the hood from opening by wind while in

transit, it is necessary to either load the machine
forward or use a suitable tie down for the hood.

2. Do not attempt to tow this machine, or damage to the
transmission may result.

3. Follow all federal and local regulations for securement.

BDirections for Use of Power Steering

1. Power steering is activated only while the engine is
running. Slow engine speeds make the steering a little
heavier. While the engine is stopped, the machine
functions in the same manner as machines without
power steering.

2. When the steering wheel is turned all the way to the
stop, the relief valve is activated. Do not hold the
steering wheel in this position for a long period of time.

3. Avoid turning the steering wheel while the machine is
stopped, or tires may wear out sooner.

4. The power steering mechanism makes the steering
easier. Be careful when driving on a road at high
speeds.

(1) Chocks

OPERATING THE MACHINE24

BGlide Steer

This machine is equipped with the Glide Steer.
It allows full time front axle drive preventing turf damage.
The rear axle has left and right axle clutches inside and
both clutch arms are connected to the front axle king pin
support with rods.
When driving straight, the rear axle clutches are engaged
and both left and right tires have traction. When turning
right or left, the rods are pulled by the king pin and
disengage the inside rear tire clutch. This will make the
front tire and outside rear tire speed differences small.

(1) Differential (A) Rear axle clutch:

"ENGAGED"
(B) Rear axle clutch:
"DISENGAGED"
(C) Rotation speed:
"DOWN"

If the adjustment is not correct or some malfunction
occurs in the system, rear clutches are engaged all times
and result in larger turn radius or turf damage. In that
case, contact your Kubota dealer for checking.

OPERATING THE MOWER

25OPERATING THE MOWER

MAKING THE MOST OF YOUR MOWER

1. When using your mower for the first time, choose a
smooth level area and cut in straight and slightly
overlapping strips.

2. The size and type of the area to be mowed will
determine the proper mowing pattern. Take into
account obstructions, such as trees, fences and
buildings. To keep grass clippings off fences,
sidewalks, etc., it is advisable to go over the outside of
the area to be mowed several times in a clockwise
direction. To mow the area remaining, work in a
counterclockwise direction so that the clippings are
dispersed onto the previously cut area.

3. Always keep the left side of the mower toward trees,
posts or other obstacles on the first trip around the
obstacle.

4. Most lawns should be mowed to keep the grass
approximately 50 to 80 mm (2 to 3 in.) high. Best
results are obtained by cutting often and not too short.
To keep a green lawn, never mow more than 1/3 of the
height of the grass or a maximum of 25 mm (1 in.) in 1
mowing.
For extremely tall grass, set the cutting height at
maximum cutting height for the first mowing, then
reset to the desired height and mow again. Allow the
grass to grow to 80 mm (3 in.), then cut off only the top
inch.

5. For best appearance, grass should be cut in the
afternoon or evening when it is free of moisture.

ADJUSTING CUTTING HEIGHT

To avoid serious injury or death:

A Do not operate mower in the "TOP" position.

BCutting Height Control Dial

Raise the mower deck to the top position. Turn the cutting
height control dial to the desired cutting height.
Lower the mower deck, and then the mower deck will be
set to the cutting height.

(1) Cutting height control dial

To avoid serious injury:
A Clear the work area of objects which might be

picked up and thrown by blades.

A Keep bystanders and animals away from the

mowing area.

A Be sure to disengage the PTO and sit on the

operator's seat before starting the engine.

1. Before adjusting the cutting height, check that all tire
pressures are correct. If necessary, adjust to the
correct tire pressure.

2. To set the cutting height, pull the hydraulic lift lever
backward to raise mower deck to the top position.

3. Turn the cutting height control dial to adjust the height.

4. Set the anti-scalp rollers' height as shown to keep
clearance between rollers and ground from 6 mm
(0.25 in.) to 13 mm (0.5 in.).

OPERATING THE MOWER26

(1) Anti-scalp roller (Rear)

(1) Hydraulic lift lever
(2) Cutting height control dial

5. Lower the mower deck by pushing the hydraulic lift
lever downward. This lowers the mower deck from the
"Transport" position to the "Operating" position.

6. Use the higher settings for mowing in a rough area or
when mowing tall grass. Lower settings should be
used only for smooth lawns where short grass is
desired.

(1) Anti-scalp roller

27OPERATING THE MOWER

Reference

A Set the position for a recommended ground clearance

of 19 mm (3/4 in.).
(Figure shows a setting position of cutting height 50 or
55 mm (2.0" or 2.25"))

(Ref.) Ground

Cutting height

inch (mm)

1" (25) *1

1.25" (32) *2 12.4 mm (0.5 in.)

1.5" (38) 19.0 mm (0.7 in.)

1.75" (44) 25.4 mm (1.0 in.)

2.0" (50)

2.25" (58) 25.4 mm (1.0 in.)

Position of bolts

1

2

clearance
between rollers
and the ground

6 mm (0.2 in.)

19.0 mm (0.7 in.)

OPERATING THE MOWER

To avoid serious injury or death:
A Do not operate the mower without the

discharge deflector being in place properly.

A This machine is equipped with the KRA (KUBOTA

Reverse Awareness) system.
This feature shuts down the engine if the operator
attempts reverse travel while any PTO driven
implement is engaged. The purpose of the KRA
system is to increase operator awareness of the risk of
back-over accidents. The KRA system incorporates an
override switch on the dash that allows the operator to
override the system and keep the PTO engaged
during reverse travel. KUBOTA strongly recommends
against overriding the KRA system, but if the operator
deems it absolutely necessary and safe to do so, he
may activate the override switch. The override switch
light flashes while activated as a reminder to the
operator that the PTO (i.e. mower, grass catcher,
snowblower, etc.) remains engaged during reverse
travel. The operator should return the KRA system to
normal operating mode as soon as possible by
momentarily disengaging the PTO.

2.5" (64)

2.75" (70) 25.4 mm (1.0 in.)

3.0" (76) *3 (31.8 mm) (1.3 in.)

3.5" (89) *3 (44.6 mm) (1.8 in.)

4.0" (102) *3 (57.4 mm) (2.3 in.)

*1. Cutting height 1" is a ground clearance of 6 mm.

*2. Cutting height 1.25" is a ground clearance of 12.4

mm.

*3. For cutting heights above 3.0". The anti-scalp rollers

will still be effective against scalping.

3

19.0 mm (0.7 in.)

BKRA system Normal Operating Mode

1. Start the engine.

2. Set the throttle lever to the "FAST" position.

(1) Throttle lever : "FAST" position

: "SLOW" position

3. Push down the PTO lever to the "ENGAGED" position.

OPERATING THE MOWER28

BPTO Lever

To engage mower blade, push the PTO lever to the
"ENGAGED" position. To stop the mower blades, pull the
PTO lever to the "DISENGAGED" position.

(1) PTO lever : "ENGAGED"

: "DISENGAGED"

A When attempting to operate the machine in reverse

with the PTO engaged, the engine will shut down.

A If you dismount from the seat while the PTO is running,

the engine will stop automatically. (Operator Presence
Control)

A Before starting the engine, pull the PTO lever to the

"DISENGAGED" position and depress brake pedal,
otherwise, the starter will not operate.

A For best cut quality and performance, always mow

with the throttle lever in "FAST" position.

BKRA system Override Mode

To avoid serious injury:
A Before and when backing, look down and

behind the machine to be sure no bystanders,
especially children, have entered the area.

A K.R.A. System override switch allows the operator to

mow or operate attachments while in reverse if the
operator deems it absolutely necessary and safe to do
so. (i.e. the operator should make sure that no
bystanders, especially children, have entered the
area.)
If the owner does not wish certain operators to utilize
the override switch allowing mowing or implement
operation in reverse, then he or she may remove the
fuse from the system to prevent override. (See NOTE
(4) below)

1. Start the engine.

2. Set the throttle to the "FAST" position.

3. Push the PTO lever to the "ENGAGED" position.

4. Stop the machine (Set the speed control pedal to
NEUTRAL) or depress the speed control pedal
forward.

5. Push the K.R.A. System override switch.

Use the speed control pedal to select the desired mowing
speed range.

(1) During heavy duty use, operate the machine at a

slower ground speed or go over the area twice.
The first pass should be with the deck at the highest
cutting position, then mow to desired height.

(2) The mower will not cut cleanly if the ground speed is

too high or if the blade speed drops due to an
overload.

1. Control ground speed by using the speed control
pedal of the machine.

A Keep the mower deck in the fully raised position when

the mower is not engaged.

(1) K.R.A. System switch

6. Look down and behind the machine to be sure that no
bystanders, especially children have entered the area.

7. Depress the speed control pedal with the heel of your
right foot to move in the reverse direction.

(1) The K.R.A. System Override Mode can not be

activated by pushing the switch while the speed
control pedal is depressed to initiate rearward
movement.

(2) The override switch light flashes while activated as

a reminder to the operator that PTO (i.e. mower,
tiller, etc.) remains engaged during reverse travel.

(3) The K.R.A. System Override Mode will remain

activated until the PTO lever is returned to the
"DISENGAGED" position.

(4) To prevent use of the K.R.A. System Override

Mode, remove the fuse located under the fender:

A The engine can be started.
A The machine PTO can be engaged if the speed

control pedal is in the neutral or forward position.

A Selection of PTO operation (i.e. mower. tiller

etc.) during reverse travel is not possible.

29OPERATING THE MOWER

(1) Fuse (A) Left rear tire

To avoid serious injury or death:
A Engine components can get extremely hot from

operation. To prevent severe burns, do not
touch these areas while the engine is running,
or immediately after it is turned off.
Never operate the engine with heat shields or
guards removed.

30 CLEANING

CLEANING

To avoid serious injury:

A Do not clean the machine with engine running.
A Be sure to set the parking brake during

cleaning.

CLEANING WITH WATER

The use of a high pressure cleaner is not recommended.
However if you use one, take care not to splash water on
engine parts such as the air filter, exhaust muffler, battery.
Do not direct jet towards hydraulic elements.

CLEANING THE MOWING SYSTEM

After each use, carefully clean the mowing deck,
particularly underneath. Switch the engine off before
cleaning your machine.
The inside part of the mowing system can also be cleaned
with water through the discharge duct.
Remove the grass container to access the discharge duct.
Operate the mowing system for a few minutes after
cleaning.

A If the mower was used under very difficult conditions

(very wet grass, mowing in a very low position), it may
be necessary to remove the cutting deck to clean it. At
the same time, you should take the opportunity to
check the condition of the blades, belts and bolts and
replace them if needed.

TIRE AND WHEELS

31TIRE AND WHEELS

TIRES

To avoid serious injury:
A Do not attempt to mount a tire. This should be

done by a qualified person with the proper
equipment.

A Always maintain the correct tire pressure.

Do not inflate tires above the recommended
pressure shown in the Operator's Manual.

A Inflation pressure in front tires rises quickly

when using compressed air.

To avoid serious injury:
A Never operate machine with a loose rim, wheel,

or axle.

A Whenever bolts are loosened, retighten to

specified torque.

A Check all bolts frequently and keep them

tightened.

BInflation Pressure

Though the inflation pressure is factory-set to the
prescribed level, it naturally drops slowly in the course of
time. Thus, check it everyday and inflate as necessary.

[Turf tire]

Recommended Inflation

Max. Pressure

160 kPa

(1.6 kgf/cm , 24 psi)

150 kPa

(1.5 kgf/cm , 22 psi)

Recommended Inflation

Max. Pressure

190 kPa

(1.9 kgf/cm , 28 psi)

140 kPa

(1.4 kgf/cm , 20 psi)

Front

Rear

[Bar tire]

Front

Rear

Tire sizes

16 x 7.50 - 8,

4PR

23 x 10.50 - 12,

4PR

Tire sizes

16 x 7.50 - 8,

4PR

23 x 10.50 - 12,

4PR

(1) Ground (A) "INSUFFICIENT"

(B) "NORMAL"
(C) "EXCESSIVE"

TIRE AND WHEELS32

WHEELS

A When re-fitting a wheel, tighten the wheel bolts to the

following torques then recheck after travelling 200 m
(220 yards) changing directions several times.

A Wheels with beveled or tapered holes:

Use the tapered wheel bolts. (Front)

(1) Bolt Front 108.5 to 130.2 N-m

(11.07 to 13.28 kgf-m)
(80 to 96 lbf-ft)

(1) Nut
(2) Spring washer

Rear 77.6 to 90.2 N-m
(7.9 to 9.2 kgf-m)
(57.2 to 66.5 lbf-ft)

MAINTENANCE

SERVICE INTERVALS

The following servicing tasks should be carried out on the machine at the stated running-time intervals.

[GR2020G]

Indication hour meter (Hr)

1

1

1

1

2

2

2

2

3

3

3

3

4

4

4

4

5

5

5

5

No. Items

1 Engine oil Change

Engine oil

2

filter

Transmissi-

3

on fluid

Transmissi-

4

on oil filter

Transmissi-

5

on strainer

Front axle

6

case oil

Front axle

7

pivot

Engine

8

shroud
panel

Engine

9

shroud

Engine start

10

system

11 OPC system Check

PTO control

12

system

13 Oiling -

14 Greasing -

Mower gear

15

box oil

Air

16

clea­ner

Pre­clea­ner
ele­ment

Air
clea­ner
ele­ment

Re­place

Change

Re­place

Clean

Change

Adjust

Clean

Clean

Check

Check

Check

Change

Clean

Clean

Re­place

25507

0

2

5

7

0

2

5

7

0

2

5

7

0

2

5

7

0

5

0

5

0

5

0

5

0

5

0

5

0

5

0

5

0

2

5

0

5

6

5

7

0

0

5

0

After

600 Hr

every

200 Hr

every

200 Hr

every

400 Hr

every

200 Hr

every

400 Hr

every

400 Hr

every

200 Hr

every

100 Hr

every

200 Hr

every
50 Hr

every
50 Hr

every
50 Hr

every
50 Hr

every
50 Hr

every
50 Hr

every

150 Hr

every
25 Hr

every
25 Hr

every

100 Hr

33MAINTENANCE

Ref.

Page

64

63

69

65

70

70

68 *2

59 *2

68 *2

49

50

50

54

53

53

62

48 *1

48

58

34 MAINTENANCE

No. Items

Carbon

17

canister air
filter

Battery

18

condition

19 Brake Check

Fuel filter

20

element

21 Fuel line

Spark plug

22

condition
and gap

Hydraulic

23

hose

Mower gear

24

box oil seal

25 Fuel system Bleed

26 Fuse

27 Blade

28 Mower belt

Check

Check

Check

Re­place

Check

Re­place

Check

Check

Re­place

Re­place

Re­place

Re­place

Re­place

25507

Indication hour meter (Hr)

1

1

1

1

2

2

2

2

3

3

3

3

4

4

4

4

5

5

5

5

6

0

2

5

7

0

2

5

7

0

2

5

7

0

2

5

7

0

2

5

5

0

5

0

5

0

5

0

5

0

5

0

5

0

5

0

5

0

7

5

0

5

0
0

After

600 Hr

every
50 Hr

every
50 Hr

every

100 Hr

every

100 Hr

every

200 Hr

every

100 Hr

every

2 years

every

200 Hr

every

200 Hr

every

2 years

every

2 years

Service

as

required

Ref.

Page

52 *3

57

61

59

69 *2

59

73 *2

68

66

*2

73

73 *2

76

73

74

76

A The jobs indicated by must be done initially.

*1 This maintenance should be done daily or more often in dusty conditions than in normal conditions.
Suggested cleaning interval is every 100 hours in normal conditions.
*2 These items should be serviced by an authorized KUBOTA Dealer.
*3 Clean or replace only if necessary.

A GASOLINE ENGINE EMISSION RELATED MAINTENANCE INSTRUCTIONS:

1. Non-warranty maintenance, repair, or replacement of the emission control devices and systems should be
performed by a qualified repair establishment or individual which has the experience and equipment to perform such
work.
See the Emissions Warranty Statement.

2. To ensure the best quality and reliability, use new KUBOTA Genuine parts or their equivalents for repair and
replacement, whenever you have maintenance done.

[GR2120, GR2120AU]

No. Items

1 Engine oil Change

2 Engine oil filter Replace

3 Transmission fluid Change

4 Transmission oil filter Replace

5 Transmission strainer Clean

6 Front axle case oil Change

7 Front axle pivot Adjust

8 Engine start system Check

9 OPC system Check

10 PTO control system Check

11 Oiling -

12 Greasing -

Check

13 Mower gear box oil

Change

Clean

14 Air cleaner element

Replace

15 Battery condition Check

16 Brake Check

17 Fan drive belt Check

Check

18 Fuel filter element

Replace

Check

19 Fuel line

Replace

Check

20 Hydraulic hose

Replace

Indication on hour meter (Hr)

50 100 150 200 250 300 350 400 450 500 550 600

After

since

every

200 Hr

every

200 Hr

every

400 Hr

every

200 Hr

every

400 Hr

every

400 Hr

every

200 Hr

every
50 Hr

every
50 Hr

every
50 Hr

every
50 Hr

every
50 Hr

every
50 Hr

every

150 Hr

every
50 Hr

every

1 year

every
50 Hr

every

100 Hr

every

100 Hr

every

100 Hr

every

400 Hr

every

100 Hr

every

2 years

every

200 Hr

every

2 years

35MAINTENANCE

Ref.

page

64

63

69

65

70

70

68 *2

49

50

50

54

53

53

62

51 *1

@

71

57

61

61

59

@

71 *2

59

@

73 *2

66

73 *2

36 MAINTENANCE

No. Items

Check

21 Radiator hose and clamp

Replace

Check

22 Intake air line

Replace

Fuel injection nozzle

23

injection pressure

24 Injection pump Check

25 Radiator Clean

26 Coolant Change

27 Mower gear box oil seal Replace

28 Engine breather hose Replace

29 Fuel system Bleed

30 Fuse Replace 73

31 Blade Replace 74

32 Mower belt Replace 76

Check

50 100 150 200 250 300 350 400 450 500 550 600

Indication on hour meter (Hr)

After

since

every

200 Hr

every

2 years

every

200 Hr

every

2 years

every

1500Hr

every

3000Hr

every

1 year

every

1 year

every

2 years

every

2 years

Service

as

Required

page

Ref.

66

73 *2

68

@

73 *3

71 *2 @

71 *2 @

72

71

73 *2

73 *2

76

A The jobs indicated by must be done initially.

*1 This maintenance should be done daily more often in dusty conditions than in normal conditions.
Suggested cleaning interval is every 100 hours in normal conditions.
*2 These items should be serviced by an authorized KUBOTA Dealer.
*3 Replace only if necessary.

A The items listed above (@ marked) are registered as emission related critical parts by KUBOTA in the U.S.EPA non-

road emission regulation. As the engine owner, you are responsible for the performance of the required maintenance
on the engine according to the above instruction.
Please see the Warranty Statement for complete details.

LUBRICANTS, FUEL AND COOLANT

Capacities Lubricants, fuel and coolant

Place

GR2020G

GR2120,

GR2120AU

37MAINTENANCE

---

Fuel

16 L

(4.2 U.S.gals.)

Coolant ---

Recovery tank ---

---

Engine crankcase

1.9 L *1

(2.0 U.S.qts.)

Transmission case 3.3 L (3.5 U.S.qts.)

Mower gear box 0.15 L (0.16 U.S.qts.)

18 L

(4.8 U.S.gals.)

---

2.1 L

(2.2 U.S.qts.)

0.25 L

(0.26 U.S.qts.)

2.8 L *1

(3.0 U.S.qts.)

---

No.2-D diesel fuel
No.1-D diesel fuel if temperature is below -10 (14 )

Automobile unleaded or regular gasoline
Unleaded gasoline 87 octane or higher
Gasohol
Methyl Tertiary Butyl Ether

Fresh clean water with anti-freeze

Engine oil: API Service
Classification CF or higher

Above 25 (77 ).........SAE30, SAE10W-30 or 15W-40

0 to 25 (32 to 77 )....SAE20, SAE10W-30 or 15W-40

Below 0 (32 )...........SAE10W, SAE10W-30 or 15W-40

Engine oil: API Service
Classification SG, SH, SJ or higher

Above -18 (0 )......SAE10W-30

Below 0 (32 ).......SAE5W-20 or 5W-30

KUBOTA SUPER UDT-2 fluid*2Front axle case 1.9 L (2.0 U.S.qts.)

Note *1 Oil amount when the oil level is at the upper level of the oil level gauge.
*2 The product name of KUBOTA genuine UDT fluid may be different from that in the Operator’s Manual depending
on countries or territories. Consult your local KUBOTA Dealer for further detail.

A Check the oil level of the transmission case with the mower lifted up.

A To prevent serious damage to hydraulic systems, use only KUBOTA genuine fluid or its equivalent.

38 MAINTENANCE

Greasing No. of greasing points Capacity Type of grease

Engine transmission
universal joint

Glide steer link bolt 2

Front axel
(Center Pin)

Glide steer rear arm 2

Glide steer arm 2

Speed control pedal
shaft

Cruise control link 2

PTO lever 1

Hydraulic lift lever 1

Seat adjuster 6

Around the hole of
the mower link

Around the pin of the
mower link

Pivot of mower link 2

Pivot of lift arm 2

2

2

4

2

2

Until grease overflows Multipurpose EP2 Grease

(NLGI Grade No. 2)

Moderate amount Oil

Front link 2

Link fulcrum 2

Choke cable
[GR2020G only]

Throttle cable 2

[MOWER] Until grease overflows Multipurpose EP2 Grease

Mower universal joint 1

Spindle shafts 3

Belt tension pivot 1

1

(NLGI Grade No. 2)

For North American market

C Engine Oil:

A Oil used in the engine should have an American Petroleum Institute (API) service classification and Proper SAE

Engine Oil according to the ambient temperatures as shown above:

A Refer to the following table for the suitable API classification engine oil according to the engine type (with internal

EGR, external EGR or non-EGR) and the fuel.

39MAINTENANCE

Fuel used

Ultra Low Sulfur Fuel
[<0.0015% (15 ppm)]

EGR: Exhaust Gas Re-circulation
A The CJ-4 engine oil is intended for DPF (Diesel Particulate Filter) type engines, and cannot be used on this

machine.

Model GR2120 ---

C Fuel:

A Cetane number of 45 is minimum. Cetane number greater than 50 is preferred, especially for temperatures below

-20 (-4 ) or elevations above 1500 m (5000 ft).

A Diesel fuels specified to EN 590 or ASTM D975 are recommended.
A No.2-D is a distillate fuel of lower volatility for engines in industrial and heavy mobile service. (SAE J313 JUN87)
A Gasohol (up to 10% ethyl alcohol, 90% unleaded gasoline by volume) or Methyl Tertiary Butyl Ether (MTBE) and

unleaded gasoline blends (up to a maximum of 15% MTBE by volume) are approved for the engine. Other gasoline/
alcohol blends are not approved.

C Transmission Oil:

*KUBOTA Super UDT-2: For an enhanced ownership experience, we highly recommend Super UDT-2 to be used
instead of standard hydraulic/transmission fluid.
Super UDT-2 is a proprietary KUBOTA formulation that deliveries superior performance and protection in all operating
conditions.
Regular UDT is also permitted for use in this machine.

A Indicated capacities of water and oil are manufacturer's estimate.

Oil class of engines except external EGR Oil class of engines with external EGR

CF, CF-4, CG-4, CH-4 or CI-4

except external EGR with external EGR

Engine oil classification (API classification)

CF or CI-4
(Class CF-4, CG-4 and CH-4 engine oils
cannot be used on EGR type engines)

40 MAINTENANCE

For other than North American market

C Engine Oil:

A Oil used in the engine should have an American Petroleum Institute (API) service classification and Proper SAE

Engine Oil according to the ambient temperatures as shown above:

A With the emission control now in effect, the CF-4 and CG-4 lubricating oils have been developed for use of a low-

sulfur fuel on on-road vehicle engines. When an off-road vehicle engine runs on a high-sulfur fuel, it is advisable to
employ the "CF or better" lubricating oil with a high Total Base Number (TBN of 10 minimum).

A Refer to the following table for the suitable API classification engine oil according to the engine type (with internal

EGR, external EGR or non-EGR) and the fuel (low-sulfur or high-sulfur fuel).

Fuel used

High Sulfur Fuel
[ 0.05% (500 ppm)]

Low Sulfur Fuel
[<0.05% (500 ppm)] or
Ultra Low Sulfur Fuel
[<0.0015% (15 ppm)]

EGR: Exhaust Gas Re-circulation
A The CJ-4 engine oil is intended for DPF (Diesel Particulate Filter) type engines, and cannot be used on this

machine.

Model GR2120AU ---

C Fuel:

A Cetane number of 45 minimum. Cetane number greater than 50 is preferred, especially for temperatures below

-20 or elevations above 1500 m.

A If diesel fuel with sulfur content greater than 0.5% (5000 ppm) sulfur content is used, reduce the service interval for

engine oil and filter by 50%.

A NEVER use diesel fuel with sulfur content greater than 0.05% (500 ppm) for EXTERNAL EGR type engine.
A DO NOT use diesel fuel with sulfur content greater than 1.0% (10000 ppm).
A Diesel fuels specified to EN 590 or ASTM D975 are recommended.
A No.2-D is a distillate fuel of lower volatility for engines in industrial and heavy mobile service. (SAE J313 JUN87)
A Gasohol (up to 10% ethyl alcohol, 90% unleaded gasoline by volume) or Methyl Tertiary Butyl Ether (MTBE) and

unleaded gasoline blends (up to a maximum of 15% MTBE by volume) are approved for the engine. Other gasoline/
alcohol blends are not approved.

C Transmission Oil:

The oil used to lubricate the transmission is also used as hydraulic fluid. To insure proper operation of the hydraulic
system and to complete lubrication of the transmission, it is important that a multi-grade transmission fluid is used in
this system. We recommend the use of KUBOTA UDT or SUPER UDT fluid for optimum protection and performance.
(Consult your local KUBOTA Dealer for further detail.)
Do not mix different brands together.

A Indicated capacities of water and oil are manufacturer's estimate.

Oil class of engines except external EGR Oil class of engines with external EGR

CF

(If the "CF-4, CG-4, CH-4 or CI-4" lubricating oil is
used with a high-sulfur fuel, change the lubricating
oil at shorter intervals. (approximately half))

CF, CF-4, CG-4, CH-4 or CI-4

except external EGR with external EGR

Engine oil classification (API classification)

---

CF or CI-4
(Class CF-4, CG-4 and CH-4 engine oils
cannot be used on EGR type engines)

PERIODIC SERVICE

DAILY CHECK

To prevent trouble from occurring, it is important to know

To avoid serious injury:
A Do not work under any hydraulically supported

devices. They can settle, suddenly leak down,
or be accidentally lowered. If necessary to work
under the machine or any machine elements
for servicing or adjustment, securely support
them with stands or suitable blocking
beforehand.

HOW TO OPEN THE HOOD

To avoid serious injury from contact with moving
parts:
A Never open the hood while the engine is

running.

A Do not touch muffler or exhaust pipes while

they are hot; Severe burns could result.

To open the hood, lift the hood as shown in the figure.

the condition of the machine. Check it before starting.

To avoid serious injury:
A Be sure to check and service the machine on a

Walking
around the
machine

41PERIODIC SERVICE

level surface with the engine shut off, the key
removed and the parking brake securely set.

No. Check item

Tire pressure, wear and

1

damage

2 Oil and water leak ---

3 Engine oil level 42

4 Transmission fluid level 46

Coolant level in the

5

recovery tank

Ref.

Page

31, 45

46

Damage to machine

6

body, tightness of all
bolts and nuts

7 Radiator screen 44

8 Panel screen 44

9 Brake free travel 61

10 Fuel level 43

11 Check air cleaner 51

Mower 1 Oil leak 53

Make sure blade cap

2

screws are tight

3 Blade wear or damage 74

4 Check all hardware. ---

Make sure all pins are in

5

place

6 Mower deck cleaning ---

Greasing
A Mower universal

7

joint

A Spindle shafts
A Belt tension pivot

---

74

---

47

PERIODIC SERVICE42

No. Check item

While sitting in
the operator's
seat

Turning the
key switch "on"

Starting the
engine

Others 1

Ref.

Page

Speed control pedal

1

Brake pedal

---

2 Brake lock ---

3 Other movable parts 48

Performance of the

1

easy checker light

Color of the exhaust

1

fumes

21

---

Safety systems.
If either of these do not
operate properly,

2

contact your local
KUBOTA Dealer

49
50
50

immediately.

Check for abnormal

3

noise and vibration.

---

Check the areas where
previous trouble was

---

experienced.

BChecking Engine Oil Level

To avoid serious injury:
A Always stop the engine and remove the key

before checking oil.

1. Check engine oil before starting and 5 minutes or more
after the engine has stopped.

2. Wipe dipstick area clean.

3. To check the oil level, remove the dipstick, wipe it
clean, replace it, and draw it out again. Check to see
that the oil level is between the 2 notches.

4. Add new oil to the prescribed level at the oil port if
necessary.

(1) Engine oil port
(2) Oil level dipstick

(1) Engine oil port

(F) "UPPER LEVEL"
(L) "LOWER LEVEL"

(1) Oil level dipstick (A) "UPPER LEVEL"

(B) "LOWER LEVEL"

A When using a different brand or viscosity oil from the

previous one, remove all of the old oil and oil filter.
Never mix 2 different types of oil.

A Use the proper Engine Oil SAE according to the

ambient temperatures. (See "LUBRICANTS, FUEL
AND COOLANT" in "MAINTENANCE" section.)

BChecking Amount of Fuel and Refueling

To avoid serious injury:
A Handle fuel carefully. If the engine is running,

do not fill the fuel tank. If engine is hot, let
engine cool several minutes before adding fuel.
Do not smoke while filling the fuel tank or
servicing the fuel system. Fill fuel tank only to
bottom of filler neck. Do not fill completely full.
The empty space in the tank allows gasoline to
expand, when it heats up. Never remove the
fuel tank cap or add fuel when the fuel tank is
hot.

43PERIODIC SERVICE

Check the fuel level. Take care that the fuel tank does not
become empty. When refueling it, park the machine on a
level surface.

GR2020G 16 L (4.2 U.S.gals.)

Fuel tank capacity

C [GR2020G]

A Do not mix oil with gasoline.
A Tighten the fuel cap until it clicks.
A Do not use the fuel cap other than KUBOTA approved

one.

Unleaded fuel is recommended. Regular leaded gasoline
with an octane rating index of 87 or higher may be used.
Avoid switching from unleaded to regular gasoline to
prevent engine damage.

A Use fuel within approximately 30 days after purchase

to avoid deterioration in fuel quality, or add fuel
stabilizer to keep fuel fresh and stabilized.

A Fuel blend differs from season to season for the best

seasonal engine performance. To prevent engine
performance troubles such as vapor lock or hard
starting, use fuel within the season in which the fuel is
purchased.

A Infrequent use of the engine during a season can

make fuel stale in the fuel tank of the machine. Stale
fuel condition can cause engine performance troubles
by varnish and plugged carburetor components.

A Seal the fuel storage container tightly and store it out

of sunlight and heat to prevent fuel degradation.

A Condensation in the fuel tank may occur because of

various operating or environmental conditions. To
reduce condensation and avoid affecting machine
operation, fill the fuel tank at the end of daily operation
and store fuel in the plastic container.

A Do not use stale fuel.
A Fill fuel tank at the end of daily operation to prevent

condensation in the fuel tank.

GR2120

GR2120AU

18 L (4.8 U.S.gals.)

Gasoline/Alcohol blends

Gasohol (up to 10% ethyl alcohol, 90% unleaded gasoline
by volume) is approved as a fuel. Other gasoline/alcohol
blends including E20 and E85 are not to be used and any
failures resulting from use of these fuels will not be
warranted.

Gasoline/Ether blends

Methyl Tertiary Butyl Ether (MTBE) and unleaded
gasoline blends (up to a maximum of 15% MTBE by
volume) are approved as a fuel. Other gasoline/ether
blends are not approved.

PERIODIC SERVICE44

C [GR2120, GR2120AU]

A Use Diesel Fuel Only

1. Use No.2 diesel fuel.

2. Use No.1 diesel fuel if the temperature is below -10
(14 ).

3. Always use a strainer when refueling to prevent fuel
injection pump contamination.

A Do not permit dirt or trash or water to get into the fuel

system.

A Be careful not to let the fuel tank become empty,

otherwise air will enter the fuel system, necessitating
bleeding before next engine start.

A Be careful not to spill fuel during refueling. If a spill

should occur, wipe it off at once, or it may cause a fire.

A To prevent condensation (water accumulation) in the

fuel tank, fill the tank before parking overnight.

BChecking and Cleaning Radiator and

Screen to Prevent Overheating

To avoid serious injury:
A Engine components can get extremely hot from

operation. To prevent severe burns, do not
touch these areas while the engine is running,
or immediately after it is turned off.

A Never operate the engine without heat shields

or guards.

To avoid serious injury:
A Be sure to stop the engine and remove the key

before cleaning.

A The air intake area must be clear of debris to prevent

the engine from overheating.

[GR2020G]

Daily or after every 5 hours of operation, check to be sure
the panel screen is clean.
Dirt or chaff on the panel screen decrease cooling
performance.

1. Remove the panel screen and remove all foreign
material.

2. Each time the panel screen is covered with grass
during operation, rub it off the screen with the hand.

3. If the dust or chaff has accumulated inside the panel,
remove the panel screen, and clean inside completely.

(1) Fuel port
(2) Fuel tank filler neck
(3) Empty space
(4) Max. fuel level

(C) Clearance
(Fuel level is under the filler neck.)

(1) Panel screen

[GR2120, GR2120AU]

Daily or after every 5 hours of operation, check to be sure
the radiator screen, radiator core and panel screen are
clean.
Dirt or chaff on the radiator screen, radiator core or panel
screen decrease cooling performance.

1. Remove the radiator screen and panel screen and
remove all foreign material.

2. Remove the dust from between the fins and the tube.

3. Tighten the fan drive belt as necessary. For this, refer
to "EVERY 100 HOURS" in Maintenance section.

4. If scale forms in the tube, clean with the scale inhibitor
or its equivalent.

5. Each time the panel screen is covered with grass
during operation, rub it off the screen with the hand.
Check the radiator screen from time to time if grass
accumulates.

6. If the dust or chaff has accumulated inside the panel,
remove the radiator screen and the panel screen, and
clean inside completely.
After cleaning, replace the radiator screen and panel
screen properly.

45PERIODIC SERVICE

BChecking Tire Pressure

To avoid serious injury:
A Do not attempt to mount a tire on a rim. This

should be done by a qualified person with the
proper equipment.

A Always maintain the correct tire pressure.

Do not inflate tires above the recommended
pressure shown in the Operator's Manual.

A Inflation pressure in front tires rises quickly

when using compressed air.

To avoid serious injury:
A Never operate machine with a loose rim, wheel,

or axle.

A Whenever bolts are loosened, retighten to

specified torque.

A Check all bolts frequently and keep them

tightened.

(1) Radiator screen
(2) Panel screen

C Inflation Pressure

Though the inflation pressure is factory-set to the
prescribed level, it naturally drops slowly in the course of
time. Thus, check it everyday and inflate as necessary.

[Turf tire]

Recommended Inflation

Max. Pressure

160 kPa

(1.6 kgf/cm , 24 psi)

150 kPa

(1.5 kgf/cm , 22 psi)

Recommended Inflation

Max. Pressure

190 kPa

(1.9 kgf/cm , 28 psi)

140 kPa

(1.4 kgf/cm , 20 psi)

Front

Rear

[Bar tire]

Front

Rear

Tire sizes

16 x 7.50 - 8,

4PR

23 x 10.50 - 12,

4PR

Tire sizes

16 x 7.50 - 8,

4PR

23 x 10.50 - 12,

4PR

PERIODIC SERVICE46

BChecking Coolant Level

[GR2120, GR2120AU]

To avoid serious injury:
A Be sure to stop the engine and remove the key

before checking coolant level.

A Do not remove the radiator cap while coolant is

hot. When cool, slowly rotate cap to the first
stop and allow sufficient time for excess
pressure to escape before removing the cap
completely.

(1) Ground (A) "INSUFFICIENT"

(B) "NORMAL"
(C) "EXCESSIVE"

BChecking Transmission Fluid Level

1. Park the machine on a flat surface, raise the mower,
shut off engine and remove the key.

2. Raise the operator's seat.

3. To check the oil level, draw out the dipstick, wipe it
clean, replace it, and draw it out again. Check to see
that the oil level lies between the 2 notches.
If the level is too low, add new oil to the prescribed
level at the oil inlet.
(See "LUBRICANTS, FUEL AND COOLANT" in
"MAINTENANCE" section.)

Check the coolant level daily both the radiator and the
recovery tank before starting engine.

1. Remove the radiator cap and check to see that the
coolant level is just below the fill port.

2. Check to see that the coolant level is between the
"FULL" and "LOW" marks of recovery tank.

3. When the coolant level drops due to evaporation, add
water only up to just below the fill port of the radiator
and the full level of the recovery tank.
In case of leakage, add anti-freeze and water in the
specified mixing ratio up to the full level.
(See "Flush Cooling System and Changing Coolant" in
"EVERY 1 YEAR" in "PERIODIC SERVICE" section.)

(1) Oil level dipstick (A) Oil level is acceptable

within this range.

A Check the oil level of the transmission case with the

mower lifted up.

A If oil level is low, do not run the engine.

(1) Radiator cap
(2) Over flow pipe

BLubricating All Grease Fittings

To avoid serious injury:
A Be sure to stop the engine and remove the key

before greasing.

Grease the following locations.

47PERIODIC SERVICE

(1) Recovery tank cap
(2) Recovery tank

(A) "FULL"
(B) "LOW"

A If the radiator cap has to be removed, follow the

caution above and securely retighten the cap.

A Use clean, distilled water and anti-freeze to fill the

radiator and the recovery tank.

A If water should leak, consult your local KUBOTA

Dealer.

(1) Spindle shaft
(2) Belt tension pivot

(1) Mower universal joint (Apply grease on the spline shaft.)

PERIODIC SERVICE48

BChecking Movable Parts

If any of the movable parts, such as levers and pedals, is
not smoothly moved because of rust or anything sticky, do
not attempt to force it into motion.
In the above case, remove the rust or the sticky thing, and
apply oil or grease on the relevant spot.
Otherwise, the machine may get damaged.

EVERY 25 HOURS

BCleaning Precleaner and Air Cleaner

Paper Element

[GR2020G]

A Operating in dusty conditions requires more frequent

maintenance.

1. Stop the engine and apply the parking brake.

2. Loosen the cover retaining knob and remove the
cover.

(1) Cover retaining knob
(2) Cover

3. Inspect the foam precleaner without removing it.

A Do not wash the paper element.

[If the foam precleaner is dirty]

1. Remove the precleaner.

(1) Element cover nut
(2) Element cover
(3) Precleaner
(4) Paper element

49PERIODIC SERVICE

2. Wash the precleaner in warm water with detergent.
Rinse the precleaner thoroughly until all traces of
detergent are eliminated. Squeeze out excess water
(do not wring). Allow the precleaner to air dry.

3. Saturate the precleaner with new engine oil.
Squeeze out all excess oil.

4. Reinstall the precleaner.

5. When the precleaner replacement is necessary, order
genuine KUBOTA parts.

EVERY 50 HOURS

BChecking Engine Start System

The Engine Start System in your machine are designed to
protect you while operating. Please check these Engine
Start System periodically. It is recommended to check the
Engine Start System before daily operation.

To avoid serious injury:
A Do not allow anyone near the machine while

testing.

A If the machine does not pass one of the

following tests, do not operate the machine.
See your local KUBOTA Dealer.

A Sit on operator's seat for all tests.

A Check the following tests before operating the

machine.

Test 1 (Safety Start Control 1)

1. Depress the brake pedal fully.

2. Engage the PTO lever.

3. Turn the key switch to the "START" position.

4. The engine should not crank.

Test 2 (Safety Start Control 2)

1. Disengage the PTO lever.

2. Release the brake pedal.

3. Turn the key to the "START" position.

4. The engine should not crank.

(1) Brake pedal
(2) PTO lever
(3) Key switch
(4) Throttle lever

PERIODIC SERVICE50

BChecking OPC System

The OPC (Operator Presence Control) system in your
machine are designed to protect you while operating.
Please check these OPC system periodically. It is
recommended to check the OPC system before daily
operation.

To avoid serious injury:
A Do not allow anyone near the machine while

testing.

A If the machine does not pass one of the

following tests, do not operate the machine.
See your local KUBOTA Dealer.

A Sit on operator's seat for all tests.

A Check the following tests before operating the

machine.

Test 1 (Seat Safety Control 1)

1. Run the engine at half throttle.

2. Engage the PTO lever.

3. Stand up. (DO NOT GET OFF THE MACHINE.)

4. Engine should shut off.

Test 2 (Seat Safety Control 2)

1. Run the engine at half throttle.

2. Disengage the PTO lever.

3. Release the brake pedal.

4. Stand up. (DO NOT GET OFF THE MACHINE.)

5. Engine should shut off.

BChecking PTO Control System

The PTO control system in your machine are designed to
protect you while operating. Please check these PTO
control system periodically - daily is best - to test function
of the PTO control system before operation.

To avoid serious injury:
A Do not allow anyone near the machine while

testing.

A If the machine does not pass one of the

following tests, do not operate the machine.
Contact your KUBOTA Dealer.

A Sit on operator's seat for all tests.

A Check the following tests before operating the

machine.

Test 1 (KUBOTA Reverse Awareness system
(KRA system) 1)

1. Start and run the engine at half throttle.

2. Engage the PTO lever.

3. Press slightly on reverse side of speed control pedal.

4. Engine should shut off.

Test 2 (KUBOTA Reverse Awareness system
(KRA system) 2)

1. Start and run the engine at 1/4 throttle.

2. Engage the PTO lever.

3. Press the KRA system override switch.

4. The KRA indicator light should flash.

5. Press slightly on the reverse side of speed control
pedal.

6. Engine should not shut off.

(1) Brake pedal
(2) PTO lever
(3) Key switch
(4) Throttle lever

Remove the fuse from under the seat before Test 3
Test 3 (KUBOTA Reverse Awareness system
(KRA system) 3)

1. Start and run the engine at 1/4 throttle.

2. Engage the PTO lever.

3. Press the KRA system override switch.

4. The KRA indicator light should not flash.

5. Press slightly on reverse side of speed control pedal.

6. Engine should shut off.

51PERIODIC SERVICE

(1) Brake pedal
(2) PTO lever
(3) Key switch
(4) Throttle lever
(5) KRA system override switch

BCleaning Air Cleaner Element

[GR2120, GR2120AU]

To avoid serious injury:
A Be sure to stop engine and remove the key

before cleaning air cleaner element.

1. Remove the air cleaner cover and element.
(1) Undo the hook.

(2) Turn the cover clockwise and detach it.

2. Clean the element:
(1) When dry dust adheres to the element, blow

compressed air from the inside, turning the
element. Pressure of compressed air must be
under 205kPa (2.1kgf/cm , 30psi).

(2) When carbon or oil adheres to the element, soak

the element in detergent for 15 minutes, and then
wash it several times in water, rinse with clean
water and dry it naturally. After element is fully
dried, inspect the inside of the element with a
light and check if it is damaged or not. (referring
to the instructions on the label attached to the
case.)

3. Replace the air cleaner element if:
Once yearly or after every sixth cleaning, whichever
comes first.

(1) Air cleaner cover
(2) Air cleaner element
(3) Evacuator valve

A The air cleaner uses a dry element, never apply oil.
A Do not run the engine with the filter element removed.
A Align the arrow marks when reinstalling the cover. If

the cover is improperly fitted, dust passes by the baffle
and directly adheres to the element.

C Evacuator valve

Open the evacuator valve one a week under ordinary
conditions - or daily when used in a dusty place - to get rid
of large particles of dust and dirt.

A Checked to see if the evacuator valve is blocked with

dust.

A Operating in dusty conditions requires more frequent

maintenance.

PERIODIC SERVICE52

BChecking Carbon Canister Air Filter

[GR2020G]

Check the carbon canister air filter every 50 hours of
operation. (more often under extremely dusty or dirty
conditions.)

To avoid serious injury:
A Always stop the engine, set the parking brake,

remove the key, and disengage PTO.

1. Remove the rear cover and remove the carbon
canister air filter.

4. If the air filter is worn out, damaged or too dirty to wash
clean, replace it with a new one.

5. Reinstall the carbon canister air filter and secure it with
the cover.

A Operating in dusty condition may require more

frequent maintenance than above.

(1) Rear cover

(1) Canister air filter
(2) Cover
(3) Carbon canister

(A) Right rear tire
(B) Air port

2. Check to see if the carbon canister air filter is worn out,
damaged or dirty.

3. If the air filter is dirty, wash the air filter in warm water
with detergent. Then rinse the air filter thoroughly until
all traces of detergent are eliminated. Squeeze out
excess water. (do not wring.) Allow the air filter to air
dry. Do not use high pressure air to clean filter.

53PERIODIC SERVICE

BChecking Gear Box Oil Level

To avoid serious injury:
A Always stop the engine and remove the key

before checking oil.

1. Park the machine on a flat surface and lower the
mower to the ground.
To check the oil level, loosen the check plug and check
to see that the oil level is just below the check plug
port.
If the level is too low, add new oil to the prescribed
level at the oil inlet.
(See "LUBRICANTS, FUEL AND COOLANT" in
"MAINTENANCE" section.)

BGreasing

To avoid serious injury:
A Be sure to stop the engine and remove the key

before greasing.

Grease the following locations.

(1) Engine transmission universal joint
(Apply grease on the spline shaft.)
(2) Engine transmission universal joint (Nipple)

(1) Check plug (Bolt)
(2) Oil filler plug

(1) Glide steer link bolt (LH, RH)

(1) Front axle (Center pin)

PERIODIC SERVICE54

(1) Glide steer rear arm

BOiling

To avoid serious injury:
A Be sure to stop the engine and remove the key

before oiling.

Oil the following locations.

(1) Glide steer arm (RH)

(1) Speed control pedal shaft (RH) (A) Fender

(1) Speed control pedal shaft (LH)

(1) Glide steer arm (LH)

55PERIODIC SERVICE

(1) Cruise control link

(1) PTO lever (fulcrum)
(2) Hydraulic lift lever (fulcrum)

(1) Around the hole of the mower link (LH, RH)
(2) Around the pin of the mower link (LH, RH)
(3) Pivot of mower link (LH, RH)
(4) Pivot of liftarm (LH, RH)

(1) Front link

(1) Seat adjuster

(1) Link fulcrum

PERIODIC SERVICE56

(1) Choke cable
(2) Throttle cable

(1) Throttle cable

(1) Throttle cable

(1) Throttle cable

57PERIODIC SERVICE

BChecking Battery Condition

To avoid the possibility of battery explosion:
For the refillable type battery, follow the
instructions below.
A Do not use or charge the refillable type battery

if the fluid level is below the LOWER (lower limit
level) mark. Otherwise, the battery component
parts may prematurely deteriorate, which may
shorten the battery's service life or cause an
explosion. Check the fluid level regularly and
add distilled water as required so that the fluid
level is between the UPPER and LOWER levels.

To avoid serious injury or death:
A When the battery is being activated, hydrogen

and oxygen gases in the battery are extremely
explosive. Keep open sparks and flames away
from the battery at all times, especially when
charging the battery.

To avoid serious injury:
A Batteries, battery posts, terminals and related

accessories contain lead and lead compounds,
and other chemicals known to the State of
California to cause cancer and birth defects or
other reproductive harm. WASH HANDS
AFTER HANDLING.

A Never remove the battery cap while the engine

is running.

A Keep electrolyte away from eyes, hands and

clothes. If you are spattered with it, wash it
away completely with water immediately and
get medical attention.

A Keep open sparks and flames away from the

battery at all times. Hydrogen gas mixed with
oxygen becomes very explosive.

A Wear eye protection and rubber gloves when

working around battery.

A Mishandling the battery shortens the service life and

adds to maintenance costs.
The original battery is maintenance free, but needs
some servicing.
If the battery is weak, the engine will be difficult to start
and the lights will be dim. It is important to check the
battery periodically.

A When exchanging an old battery for new one, use

battery of equal specification in table below.

Battery

Type

10U1L 12 - 25 300 6 to 10

51R1280454304.5

Volts

(V)

Reserve
Capacity

(min)

Capacity

20 HR

(Ah)

Cold

Cranking

Amps

Normal

Charging

Rate (A)

(For non-accessible maintenance-free type batteries.)
Maintenance-free, non-accessible batteries are designed
to eliminate the need to add water. Yet the volume of
electrolyte above plates may eventually become depleted
due to abnormal conditions such as high heat or improper
regulator setting. Use a voltmeter to check the state of
charge. (See reference chart below to determine if
charging is necessary.)

Battery voltage Reference state of charge

12.6 100%(Full charge)

12.4 75%

12.2 50%

12.0 25%

11.8 0%

C Battery Charging

To avoid serious injury or death:
A When the battery is being activated, hydrogen

and oxygen gases in the battery are extremely
explosive. Keep open sparks and flames away
from the battery at all times, especially when
charging the battery.

The factory-installed battery is of non-refillable type.
If the battery is weak, charge the battery or replace it
with new one.

To avoid serious injury:
A When disconnecting the cable from the battery,

start with the negative terminal first. When
connecting the cable to the battery, start with
the positive terminal first.

A Never check battery charge by placing a metal

object across the posts.
Use a voltmeter or hydrometer.

PERIODIC SERVICE58

EVERY 100 HOURS

BReplacing Air Cleaner Paper Element

[GR2020G]

1. Loosen the cover retaining knob and remove the
cover.

(1) Battery
(2) Ground cable

(1) Battery
(2) Ground cable

(+): Positive terminal
(-): Negative terminal

(+): Positive terminal
(-): Negative terminal

1. To slow charge the battery, connect the battery
positive terminal to the charger positive terminal and
the negative to the negative, then charge for at least 1
hour at 6 to 10 amperes (10U1L) or 4.5 amperes
(51R).

2. A boost charge is only for emergencies. It will partially
charge the battery at a high rate and in a short time.
When using a boost-charged battery, it is necessary to
recharge the battery as early as possible.
Failure to do this will shorten the battery's service life.

3. When the specific gravity of electrolyte is between

1.27 and 1.29 the charging is completed.

C Battery for storage

1. When storing the machine for a long period, remove
the battery from machine, adjust the electrolyte to the
proper level and store in a dry place out of direct
sunlight.

2. The battery self-discharges while it is stored.
Recharge it once every 3 months in hot seasons and
once every 6 months in cold seasons.

(1) Cover retaining knob
(2) Cover

2. Remove the element cover nut, the element cover,
and the paper element with the precleaner.

(1) Element cover nut
(2) Element cover
(3) Precleaner
(4) Paper element

3. Carefully remove the precleaner from the paper
element. Service the precleaner as described.
(See "Cleaning Precleaner and Air Cleaner Paper
Element" in EVERY 25 HOURS.)

A Operating in dusty condition may require more

frequent maintenance than above.

59PERIODIC SERVICE

A Do not wash a paper-element. Do not oil a paper-

element. Do not use pressurized air to clean a paper­element, as this will damage the element. Replace a
dirty, bent, or damaged element with a genuine
KUBOTA element. Handle new elements carefully; do
not use if the sealing surfaces are bent or damaged.

4. When servicing the air cleaner, check the air cleaner
base. Make sure it is secured and not bent or
damaged. Also, check the element cover for damage
or improper fit. Replace all damaged air cleaner
components.

A If any loose dirt or debris fell on the air cleaner base

when the element was removed, carefully remove it
and wipe the base clean. Be careful that none of it
drops into the intake throat. Check the condition of the
rubber seal on the air cleaner stud. If the condition is
questionable in any way, replace it with the new seal
packaged with the replacement element.

5. Reinstall the paper element, precleaner, element
cover, element cover nut, and air cleaner cover.
Secure cover with the cover retaining knob.

6. When element replacement is necessary, order
genuine KUBOTA parts.

BCleaning Engine Shroud Panel

[GR2020G]

Consult your local KUBOTA for this service.

BChecking Fuel Lines, Fuel Vapor Lines

and Fuel Filter

To avoid serious injury:
A Be sure to stop the engine and remove the key

when attempting to make the following checks
and changes.

A Never fail to check the fuel lines and fuel vapor

lines periodically. The fuel lines and fuel vapor
lines are subject to wear and aging. Fuel may
leak out onto the running engine, causing a
fire.

A Only for GR2020G, check the fuel vapor lines.

The fuel line and fuel vapor line connections should be
checked annually or every 100 service hours, whichever
comes first.

1. The fuel line and fuel vapor line are made of rubber
and ages regardless of service period.

2. If the fuel line, fuel vapor line and clamps are found to
be damaged or deteriorated, replace them.

3. Check fuel filter, if it is clogged by debris or
contaminated with water, replace it.

A When the fuel line and fuel vapor line are disconnected

for maintenance or repair, close both ends of the fuel
line and fuel vapor line with a piece of clean cloth or
paper to prevent dust and dirt from entering. In
addition, particular care must be taken not to admit
dust and dirt into the fuel pump. Entrance of even a
small amount dust or dirt cause premature wear and
malfunction of the fuel pump.

PERIODIC SERVICE60

(1) Pipe clamps
(2) Fuel filter
(3) Fuel line
(4) Fuel cock

(1) Fuel vapor line
(2) Pipe clamps

(1) Pipe clamps
(2) Fuel line
(3) Fuel filter

(1) Pipe clamps
(2) Fuel line
(3) Fuel filter

(1) Fuel vapor line
(2) Pipe clamps
(3) Carbon canister

(A) Right rear tire

61PERIODIC SERVICE

BChecking Brake

To avoid serious injury:
A When checking brake, park the machine on a

flat area, block wheels, stop the engine and
remove the key.

Correct free travel ranges from 15 to 25 mm (0.59 to 0.98
in.). If it is not correct, consult your local KUBOTA dealer.

BChecking Fan Drive Belt Tension

[GR2120, GR2120AU]

To avoid serious injury:
A Be sure to stop the engine and remove the key

before checking belt tension.

If the fan drive belt becomes loose, the engine may
overheat. To adjust, remove the right cover. Then loosen
the tension bolt and adjusting bolt and move the dynamo
outward to tighten the belt. After adjustment, securely
tighten the bolts.

Moderate belt tension:
The belt should deflect approx. 10 mm (0.39 in.) when the
center of the belt is depressed with finger pressure of 98
N (10 kgf).

(1) Brake pedal (A) Free travel 15 to 25 mm

(0.59 to 0.98 in.)

(1) Right cover

PERIODIC SERVICE62

EVERY 150 HOURS

BChanging Gear Box Oil

To avoid serious injury:
A Be sure to stop the engine and remove the key

before changing the oil.

1. To drain the used oil, remove the filler plug at the gear
box, tilt the mower deck and drain the oil completely
into the oil pan.

2. Fill with the new oil up to the check plug port.
(See "LUBRICANTS, FUEL AND COOLANT" in
"MAINTENANCE" section.)

3. After filling reinstall the filler plug and the check plug.

(1) Fan drive belt
(2) Dynamo
(3) Tension bolt
(4) Adjusting bolt
(5) Cap

(A) Approx. 10 mm (0.39 in.)
(M) "MOVE"
(L) "LEFT"
(X) Incorrect belt pass

A When replacing the fan drive belt, be careful not to

catch it on the cap under the water pump.

(1) Check plug (Bolt)
(2) Oil filler plug

EVERY 200 HOURS

BReplacing Engine Oil Filter Cartridge

To avoid serious injury:
A Be sure to stop the engine and remove the key

before changing the oil and the oil filter
cartridge.

A Allow engine to cool down sufficiently; oil can

be hot and may cause burns.

1. The oil filter cartridge must be changed every 200
service hours.

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

3. Tighten the filter quickly until it contacts the mounting
surface.

[GR2020G]

Tighten filter by hand.

[GR2120, GR2120AU]

Tighten filter by hand an additional 1/2 turn only.

4. After the new cartridge has been replaced, the engine
oil level normally lowers a little. Add engine oil to
proper level. Check for oil leaks around filter gasket.

63PERIODIC SERVICE

(1) Engine oil filter cartridge

A To prevent serious damage to the engine,

replacement element of the recommended type must
be used. Use only a genuine KUBOTA filter or its
equivalent.

(1) Engine oil filter cartridge

PERIODIC SERVICE64

BChanging Engine Oil

To avoid serious injury:
A Be sure to stop the engine and remove the key

before changing the oil.

A Allow engine to cool down sufficiently; oil can

be hot and may cause burns.

1. To keep dirt, debris, etc., out of the engine, clean the
area around the oil fill cap/dipstick before removing it.

2. Remove the oil drain plug, the oil fill cap, and the
dipstick. Be sure to allow ample time for complete
drainage.

(1) Engine oil port
(2) Oil level dipstick

(F) "UPPER LEVEL"
(L) "LOWER LEVEL"

(1) Drain plug

(1) Drain plug

3. The used oil can be drained out more easily if the
engine is warm.

4. Reinstall the drain plug. Make sure it is tightened to

13.6 N-m (10 lbf-ft) torque.

5. Fill the crankcase, with new oil of the proper type, to
the "F" mark on the dipstick. (See "LUBRICANTS,
FUEL AND COOLANT" in Maintenance section.)
Always check the level with the dipstick before adding
more oil.

(1) Engine oil port

(1) Oil level dipstick (A) "UPPER LEVEL"

(B) "LOWER LEVEL"

6. To check the oil level. Remove the dipstick, wipe it
clean, insert it and draw it out again. Check to see that
the oil level is between the 2 marks.

7. Reinstall the oil fill cap and tighten it securely.
Reinstall the dipstick.

A To prevent extensive engine wear or damage, always

maintain the proper oil level in the crankcase. Never
operate the engine with the oil level below the "L" mark
or over the "F" mark on the dipstick.

BReplacing Transmission Oil Filter

Cartridge

65PERIODIC SERVICE

To avoid serious injury:
A Be sure to stop the engine and remove the key

before changing the oil filter cartridge.

A Allow transmission case to cool down

sufficiently; oil can be hot and may cause
burns.

1. The oil filter cartridge must be changed every 200
service hours.

2. Remove rear cover.

(1) Transmission oil filter cartridge (2) Gasket

5. Apply a slight coat of oil onto the gasket of new filter.

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

7. After the new cartridge has been replaced, the
transmission fluid level normally lowers a little. Add
fluid to proper level. Check for oil leaks around filter
gasket.

8. Assemble the rear cover.

A To prevent serious damage or premature failure to the

hydraulic system, the replacement filter must be a
highly efficient, 10 filter. Use only a genuine
KUBOTA filter or its equivalent.

(1) Rear cover

3. Remove the oil filter cartridge by using the filter
wrench.

(1) Transmission oil filter cartridge

4. Lightly tighten the screw (A) by using a screwdriver.

PERIODIC SERVICE66

BChecking Radiator Hose and Clamp

[GR2120, GR2120AU]

Check to see if radiator hoses are properly fixed every 200
hours of operation or 6 months, whichever comes first.

1. If hose clamps are loose or water leaks, tighten clamps
securely.

2. Replace hoses and tighten hose clamps securely, if
radiator hoses are swollen, hardened or cracked.

(1) Radiator core
(2) Radiator hose

BChecking Hydraulic Hose

To avoid serious injury:
A Be sure to stop the engine and remove the key

before checking and replacing hydraulic hose.

A Allow transmission case to cool down

sufficiently; oil can be hot and may cause
burns.

Check to see if hydraulic hoses are properly fixed every
200 hours of operation.

1. Check to see that all lines and hose clamps are tight
and not damaged.

2. If hoses and clamps are found worn or damaged,
replace or repair them at once.

(1) Power steering hose (RH)
(2) Power steering hose (LH)

(1) Power steering hose (RH)

67PERIODIC SERVICE

(1) Power steering hose (RH)

(1) Power steering hose (LH)

(1) Mower lift cylinder hose

(1) Power steering hose (LH)

PERIODIC SERVICE68

BAdjusting Front Axle Pivot

If the front axle pivot pin adjustment is not correct,
vibration in the front wheel can occur. When vibration
occurs please contact your KUBOTA Dealer to adjust the
free travel of front axle.

BChecking Spark Plug Condition & Gap

[GR2020G]

Remove the spark plugs, check condition, and reset the
gap or replace with new plugs as necessary.

1. Open the hood.

2. Before removing spark plugs, the area around the
base of the plug to keep dirt and debris out of the
engine.

3. Remove the spark plug wires from spark plugs.

4. Use a spark plug wrench to remove the spark plugs.

5. Remove plugs and check its condition.
Replace the plug if worn or reuse is questionable.

6. Inspect spark plugs for cracked porcelain, pitted
electrodes, or other wear and damage. Replace the
spark plug if necessary.

8. Reinstall the spark plug into the cylinder head.

Tightening torque

24.4 to 29.8 N-m
(18 to 22 lbf-ft)

BCleaning Engine Shroud

[GR2020G]

Consult your local KUBOTA Dealer for this service.

(1) Spark plug

A Do not clean the spark plug in a machine using

abrasive grit. Some grit could remain in the spark plug
and enter the engine causing extensive wear and
damage.

Recommended spark plug RC12YC CHAMPION

7. Check the gap using a wire feeler gauge. Adjust the
gap to 0.76 mm (0.030 in.) by carefully bending the
ground electrode.

BChecking Intake Air Line

[GR2120, GR2120AU]

1. Check to see that hoses and hose clamps are tight and
not damaged.

2. If hoses and clamps are found worn or damaged,
replace or repair them at once.

(1) Hose
(2) Clamp

BReplacing Fuel Filter

[GR2020G]

Change fuel filter every 200 hours. Consult your local
KUBOTA Dealer for this service.

EVERY 400 HOURS

BChanging Transmission Fluid

To avoid serious injury:
A Be sure to stop the engine and remove the key

before changing or checking the oil.

A Allow transmission case to cool down

sufficiently; oil can be hot and may cause
burns.

The fluid in the transmission case is also used for the
hydrostatic drive system.

1. To drain the transmission oil, place oil pan underneath
the transmission case and remove the drain plug.

69PERIODIC SERVICE

(1) Transmission oil filter cartridge

3. Remove the dipstick and fill with the new oil.

4. After running the engine for a few minutes, stop it and
check the oil level again and add oil to the prescribed
level if necessary.

(1) Suction pipe
(2) Seal washer
(3) Drain plug

2. After draining, disassemble and clean the strainer and
change the oil filter cartridge. After reassembling, fill
with UDT or SUPER UDT hydrostatic transmission
fluid, or its equivalent.

(1) Dipstick (A) Oil level is acceptable within this range

A Check the oil level of the transmission case with the

mower lifted up.

A Operate only at low rpms immediately after changing

the transmission fluid and filter cartridge.
Keep the engine at medium speed for a few minutes to
insure proper lubrication of all parts so there is no
damage to transmission.

A Do not engage PTO before checking the oil level.

PERIODIC SERVICE70

BCleaning Transmission Strainer

When changing the transmission fluid, disassemble and
rinse the strainer with nonflammable solvent to completely
clean off filings.
Check "O" rings. Replace it if damaged, cracked or
hardened.
When reassembling be careful not to damage the parts.

(1) Suction pipe
(2) Strainer
(3) Boss
(4) O-ring (Small)
(5) O-ring (Large)

BChanging Front Axle Case Oil

1. Park the machine on a firm, flat and level surface.

2. To drain the used oil, remove the right and left drain
plugs and filling plug at the front axle case and drain
the oil completely into the oil pan.

3. After draining reinstall the drain plugs.

4. Remove the right and left breather plugs.

5. Fill with the new oil up to the upper notch on the
dipstick.
(See "LUBRICANTS, FUEL AND COOLANT" in
"MAINTENANCE" section.)

A After 10 minutes, check the oil level again; add oil to

prescribed level.

6. After filling reinstall the filling plug and breather plugs.

Oil capacity 1.9 L (2.0 U.S.qts)

A Since the fine filings in the oil can damage the

precision component parts of the hydraulic system, the
end of the suction line is provided with an oil strainer.

(1) Breather plug
(2) Filling plug with dipstick
(3) Drain plug

(A) Oil level is acceptable
within this range
(F) FRONT
(L) Left rear wheel
(R) Right rear wheel

BReplacing Fuel Filter

[GR2120, GR2120AU]

Change fuel filter every 400 hours. Consult your local
KUBOTA Dealer for this service.

EVERY 1500 HOURS

BChecking Fuel Injection Nozzle (Injection

Pressure)

[GR2120, GR2120AU]

Consult your local KUBOTA Dealer for this service.

EVERY 3000 HOURS

BChecking Injection Pump

[GR2120, GR2120AU]

Consult your local KUBOTA Dealer for this service.

EVERY 1 YEAR

71PERIODIC SERVICE

(1) Radiator drain plug

BReplacing Air Cleaner Element

[GR2120, GR2120AU]

Change the element once a year.

BFlush Cooling System and Changing

Coolant

[GR2120, GR2120AU]

To avoid serious injury:
A Do not remove the radiator cap when the

engine is hot. Then loosen cap slightly to the
stop to relieve any excess pressure before
removing cap completely.

1. Stop the engine and let cool down.

2. To drain the coolant, remove the radiator drain plug
and the engine drain plug, and remove the radiator
cap. The radiator cap must be removed to completely
drain the coolant.

(1) Engine drain plug

3. After all coolant is drained, install the drain plugs.

4. Fill with clean water and cooling system cleaner.

5. Follow directions of the cleaner instruction.

6. After flushing, fill with clean water and anti-freeze until
the coolant level is just below the fill port on the
radiator.
Install the radiator cap securely.

7. Fill with coolant up to "FULL" on the recovery tank.

8. Start and operate the engine for a few minutes.

9. Stop the engine and let cool.

10.Check coolant level of recovery tank and add coolant
if necessary.

PERIODIC SERVICE72

(1) Clamp
(2) Recovery tank
(3) Recovery tank cap

A Do not start engine without coolant.
A Use clean, distilled water and anti-freeze to fill the

radiator and recovery tank.

A When the anti-freeze is mixed with water, the anti-

freeze mixing ratio must be less than 50%.

A Securely tighten radiator cap. If the cap is loose or

improperly fitted, water may leak out and the engine
could overheat.

(A) "FULL"
(B) "LOW"

BAnti-freeze

[GR2120, GR2120AU]

To avoid serious injury:
A When using anti-freeze, put on some protection

such as rubber gloves. (Anti-freeze contains
poison.)

A If it is swallowed, seek immediate medical help.

Do NOT make a person throw up unless told to
do so by poison control or a health care
professional. Use standard first aid and CPR
for signs of shock or cardiac arrest. Call your
local Poison Control Center or your local
emergency number for further assistance.

A When anti-freeze comes in contact with the

skin or clothing, wash it off immediately.

A Do not mix different types of Anti-freeze.

The mixture can produce chemical reaction
causing harmful substances.

A Anti-freeze is extremely flammable and

explosive under certain conditions. Keep fire
and children away from anti-freeze.

A When draining fluids from the engine, place

some container underneath the engine body.

A Do not pour waste onto the ground, down a

drain, or into any water source.

A Also, observe the relevant environmental

protection regulations when disposing of anti­freeze.

Always use a 50/50 mix of long-life coolant and clean soft
water in KUBOTA engines.
Consult your local KUBOTA dealer concerning coolant for
extreme conditions.

1. Long-life coolant (hereafter LLC) comes in several
types. Use ethylene glycol (EG) type for this engine.

2. Before employing LLC-mixed cooling water, fill the
radiator with fresh water and empty it again.
Repeat this procedure 2 or 3 times to clean up the
inside.

3. Mixing the LLC
Premix 50% LLC with 50% clean soft water. When
mixing, stir it up well, and then fill into the radiator.

4. The procedure for the mixing of water and anti-freeze
differs according to the make of the anti-freeze and the
ambient temperature. Refer to SAE J1034 standard,
more specifically also to SAE J814c.

A When mixing the anti-freeze with water, the anti-freeze

mixing ratio is 50%.

Vol %

Freezing Point Boiling Point*

Anti-freeze

50 -37 -34 108 226

73PERIODIC SERVICE

* At 1.013 x 10 Pa (760 mmHg) pressure (atmospheric).

A higher boiling point is obtained by using a radiator
pressure cap which permits the development of pressure
within the cooling system.

5. Adding the LLC
(1) Add only water if the coolant level reduces in the

cooling system by evaporation.

(2) If there is a mixture leak, add the LLC of the same

manufacturer and type in the mixing ratio 50%.

* Never add any long-life coolant of different

manufacturer. (Different brands may have
different additive components, and the engine
may fail to perform as specified.)

6. When the LLC is mixed, do not employ any radiator
cleaning agent. The LLC contains anti-corrosive
agent. 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
2 years. Be sure to change the coolant every 2 years.

A The above data represent industry standards that

necessitate a minimum glycol content in the
concentrated anti-freeze.

BReplacing Intake Air Line

[GR2120, GR2120AU]

(See "Checking Intake Air Line" in every 200 hours
maintenance.)

SERVICE AS REQUIRED

BReplacing Fuses

Replacement of the fuse.

1. Open the hood.

2. Remove the blown fuse.

3. Place a new 3A, 10A, 15A fuse or 40A slow blow fuse
in position.

EVERY 2 YEARS

BReplacing Hydraulic Hose

Replace hoses and hose clamps every 2 years or earlier
if checked and found that hoses are swollen, hardened or
cracked.

BReplacing Fuel Lines and Fuel Vapor

Lines

Consult your local KUBOTA Dealer for this service.

BReplacing Engine Breather Hose

[GR2120, GR2120AU]

Consult your local KUBOTA Dealer for this service.

BReplacing Radiator Hose

[GR2120, GR2120AU]

Replace hoses and clamp bands every 2 years or earlier
if checked and found that hoses are swollen, hardened or
cracked.

(1) Fuse location

(2) Slow blow fuse (A) Starter

BReplacing Mower Gear Box Oil Seal

Consult your local KUBOTA Dealer for this service.

PERIODIC SERVICE74

(2) Slow blow fuse (A) Starter

BReplacing bulbs

(A) Replacement of the headlight bulb

1. Open hood.

2. Turn bulb socket to remove socket from headlight
housing.

3. Push bulb down and turn 1/4 turn to remove bulb from
the socket.

4. Install new bulb to the socket.

5. Install the socket in housing.

6. Close hood.

Headlight bulb 24W

(B) Replacement of the Indicator light bulb

1. Open hood.

2. Turn bad bulb socket to the left.
And remove it.

3. Pull bulb from the socket.

4. Push new bulb into the socket.

5. Install the socket.

6. Close hood.

Indicator light bulb

14.0 Rated Voltage/0.27
AMP/2 MSCP

(1) KRA system (A) Left rear tire

A If the new fuse happens to blow out within a short time,

contact your dealer for inspection and repair. Never
"jump" the fuse with wire or foil, or install a larger
capacity fuse than is recommended.

a: Stamp or stick label "E/G STOP"
b: Stamp or stick label "IG/M"
c: Stamp or stick label "OPC"

C Protected circuit

FUSE NO.

(ID LABEL)

E/G STOP 15 Engine stop timer relay

(1)

IG/M 10 Fuel pump, Head light, etc.

OPC 3 Engine running circuit

(2) ---

(3) --- 3 KRA system

CAPACITY

(A)

Slow blow fuse40Check circuit against

Protected circuit

wrong battery connection

BChecking and Replacing Blade

To avoid serious injury:

A Be sure to stop the engine and remove the key.
A Blades may be sharp. When you handle blades,

wear heavy gloves or wrap end of blade with a
rag.

C Checking

The blade cutting edges should be kept sharp at all times.
Sharpen the cutting edges, if they resemble blade (B).
Replace the blades if they appear similar to blade (C).

(A) New blade
(B) Worn blade
(C) Cracked blade

C Replacing

1. Remove the mower deck from the machine and turn it
over to expose the blades.

2. Wedge a block of wood between the blade and mower
housing or use a box wrench over the pulley nut to
prevent the spindle from rotating while removing the
blade bolts; loosen the blade bolt as illustrated.

A Use the proper metric size box or socket wrench to

tighten or loosen the blade mounting bolt.

75PERIODIC SERVICE

(1) Spindle holder
(2) Cover
(3) Blade
(4) Cup washer
(5) Lock washer
(6) Bolt

(1) Block (A) "LOOSEN"

3. To sharpen the blades yourself, clamp the blade
securely in a vise.
Use a large mill file and file along the original bevel
until it becomes sharp.

4. To check the blade for balance, place a small rod
through the center hole. If the blade is not balanced,
file the heavy side of the blade until balance is
achieved.

5. To attach blades, be sure to install the 2 cup washers
and lock washer between the blade and the bolt head.

A Make sure that the cup washer is not flattened out or

worn; this may cause blade to slip excessively.
Replace the 2 cup washers if either is damaged.

6. Before checking or replacing the blade, wipe grass
and mud off the top and the inside of the mower.
Especially clean up the inside of the belt cover,
because otherwise the belt life will be reduced.

A Tighten the bolts of the outer blades from 103 to 118

N-m (76 to 87 lbf-ft, 10.5 to 12.0 kgf-m) of torque.

A To prolong the service life of the blades, rearrange

them as shown in the figure below periodically.

(1) LH blade
(2) Center blade
(3) RH blade

PERIODIC SERVICE76

BMower Belt Replacement

1. Remove the mower deck from the machine according
to the procedure "DISMOUNTING THE MOWER
DECK".

2. Remove the left and right hand shield from the mower
deck.

3. Clean around the gear box.

4. Remove the belt from the tension pulley.

5. Remove the right hand bracket which mounts the gear
box to the mower deck and slip the belt over the top of
the gear box.

6. To install a new belt, reverse the above procedure.

Tighten each bolt with following torque.
A Bolts (4) (For aluminum gear case)

39.2 to 44.1 N-m (28.9 to 32.5 lbf-ft, 4.0 to 4.5 kgf­m)

A Bolts and Nuts (5)

48.1 to 55.9 N-m (35.5 to 41.2 lbf-ft, 4.9 to 5.7 kgf­m)

(1) Tension pulley
(2) Bracket (RH)
(3) Belt
(4) Bolt
(5) Bolt and Nut

BBleeding Fuel System

[GR2120, GR2120AU]

Air must be removed:

1. When the fuel filter or lines are removed.

2. When tank is completely empty.

3. After the machine has not been used for a long period
of time.

C Bleeding procedure is as follows:

1. Fill the fuel tank with fuel.

2. Turn the key switch to the "ON" position and hold it for
about 10 seconds.

3. Start the engine and run for about 30 seconds, and
then stop the engine.

ADJUSTMENT

GENERAL TORQUE SPECIFICATION

77ADJUSTMENT

SAE grade No.

(lbf-ft)

1/4

5/16

3/8

7/16

1/2

9/16

(N-m)

(kgf-m)

(lbf-ft)
(N-m)

(kgf-m)

(lbf-ft)
(N-m)

(kgf-m)

(lbf-ft)
(N-m)

(kgf-m)

(lbf-ft)
(N-m)

(kgf-m)

(lbf-ft)
(N-m)

(kgf-m)

American standard cap screws

with UNC or UNF threads

GR.5 GR.8

8 - 9.6

10.7 - 12.9

1.11 - 1.33

17 - 20.5

23.1 - 27.8

2.35 - 2.84

35 - 42

47.5 - 57.0

4.84 - 5.82

56 - 66

75.9 - 89.5

7.74 - 9.12

80 - 96

108.5 - 130.2

11.07 - 13.29

110 - 132

149.2 - 179.0

15.22 - 18.27

10.37 - 12.44

149.2 - 179.0

15.22 - 18.27

22.14 - 26.57

12 - 14.4

16.1 - 19.3

1.66 - 1.99

24 - 29

32.5 - 39.3

3.31 - 4.01

45 - 54

61.0 - 73.2

6.22 - 7.47

75 - 90

101.7 - 122

110 - 132

160 - 192

217 - 260.4

Property class

(lbf-ft)

M6

M8

M10

M12

M14

M16

(N-m)

(kgf-m)

(lbf-ft)
(N-m)

(kgf-m)

(lbf-ft)
(N-m)

(kgf-m)

(lbf-ft)
(N-m)

(kgf-m)

(lbf-ft)
(N-m)

(kgf-m)

(lbf-ft)
(N-m)

(kgf-m)

Metric cap screws

Class 8.8 Class 10.9

7.2 - 8.3

9.81 - 11.3

1.0 - 1.15

17.4 - 20.2

23.6 - 27.4

2.4 - 2.8

35.5 - 41.2

48.1 - 55.8

4.9 - 5.7

57.2 - 66.5

77.5 - 90.1

7.9 - 9.2

91.2 - 108
124 - 147

12.6 - 15.0

145 - 166
196 - 225

20.0 - 23.0

21.7 - 25.3

29.4 - 34.3

3.0 - 3.5

44.9 - 52.1

60.8 - 70.5

6.2 - 7.2

76.0 - 86.8
103 - 117

10.5 - 12.0

123 - 144
167 - 196

17.0 - 20.0

192 - 224
260 - 303

26.5 - 31.0

5/8

(lbf-ft)
(N-m)

(kgf-m)

150 - 180

203.4 - 244.1

20.75 - 24.91

220 - 264

298.3 - 358.0

30.44 - 36.53

78 ADJUSTMENT

TIGHTENING TORQUE CHART

Thread

size

d (mm)

M8 12 or 13

M10 14 or 17

M12 17 or 19

M14 19 or 22

A Figure "7" on the top of the bolt indicates that the bolt is of special material.
A Before tightening, check the figure on the top of bolt.

Hexa-Bolt
Head size

B (mm)

No mark 7T

lbf-ft N-m kgf-m lbf-ft N-m kgf-m

13.0 - 15.2

(14.1 1.1)

28.9 - 33.3

(31.1 2.2)

46.3 - 53.5

(49.9 3.6)

79.6 - 92.6

(86.1 6.5)

17.8 - 20.6

(19.2 1.4)

39.3 - 45.1

(42.2 2.9)

62.8 - 72.6

(67.7 4.9)

107.9 - 125.5

(116.7 8.8)

1.9 - 2.1

(2.0 0.1)

4.0 - 4.6

(4.3 0.3)

6.4 - 7.4

(6.9 0.5)

11.0 - 12.8

(11.9 0.9)

17.5 - 20.3

(18.9 1.4)

35.4 - 41.2

(38.3 2.9)

57.1 - 66.5

(61.8 4.7)

91.1 - 108.5

(99.8 8.7)

23.5 - 27.5

(25.5 2.0)

48.1 - 55.9

(52.0 3.9)

77.6 - 90.2

(83.9 6.3)

123.6 - 147.0

(135.3 11.7)

2.4 - 2.8

(2.6 0.2)

4.9 - 5.7

(5.3 0.4)

8.0 - 9.2

(8.6 0.6)

12.6 - 15.0

(13.8 1.2)

STORAGE

To avoid serious injury:
A To reduce fire hazards, allow the engine and

exhaust system to cool before storing the
machine in an enclosed space or near
combustible materials.

A To avoid the danger of exhaust fume

poisoning, do not operate the engine in a
closed building without proper ventilation.

A Do not clean the machine with engine running.
A To avoid fire hazards, Do not leave grass and

leaves in the mower and the grass catcher.

A When storing, remove the key from the key

switch to avoid operation by unauthorized
persons.

79STORAGE

[GR2020G]

11.The fuel system must be completely emptied, or the
gasoline must be treated with a stabilizer to prevent
deterioration. If you choose to use a stabilizer, follow
the manufacturer's recommendations, and add the
correct amount for the capacity of the fuel system. Fill
the fuel tank with clean, fresh gasoline. Run the engine
for 2-3 minutes to get stabilized fuel into the rest of the
system. Close the fuel shut-off valve when the unit is
being stored.
To empty the system, run the engine until the tank and
the system are empty.

12.Remove the spark plugs. Add 1 tablespoon of engine
oil into each spark plug hole. Install the plugs, but do
not connect the plug leads. Crank the engine 2 or 3
revolutions.

When the machine will not be operated for over 2 months,
clean the machine and perform the following operations
before storage.

1. Repair parts as necessary.

2. Check bolts and nuts and tighten as necessary.

3. Apply grease or engine oil to parts most likely to rust.

4. Inflate the tires to a little above the standard pressure
levels. (Approximately 110%)

5. Lower the mower to the ground.

6. Remove the battery from the machine, recharge it,
adjust the electrolyte to the proper level, and store in a
cool dry place.
The battery discharges over time even while in
storage. Recharge it once a month in hot seasons and
once every 2 months in cold seasons.

7. Drain fuel tank, fuel lines.

8. Store the machine where it is dry and sheltered from
rain. Cover the machine with a tarpaulin.

9. Moisture content in most grasses can damage the
mower and grass catcher if these components are not
properly cleaned after use.
Make sure the mower and the grass catcher are clean
and completely empty before storage.

10.Jack the machine up and place blocks under the front
and rear axles so that all 4 tires are off the ground.
Keep the tires out of direct sunlight and extreme heat.

A When washing the machine, be sure to stop the

engine. Allow sufficient time for the engine to cool
before washing.

A Cover the machine after the muffler and the engine

have cooled down.

REMOVING THE MOWER FROM STORAGE

1. Check the tire inflation pressure and adjust as
required.

2. Install the battery. Before installing the battery, be sure
it is fully charged.

3. Do daily checking. (See "DAILY CHECK" in
"PERIODIC SERVICE" section.)

4. Check all fluid levels. (engine oil, hydrostatic oil)

5. Start the engine. Shut the engine off and walk around
the machine and make a visual inspection looking for
evidence of oil or other fluids.

6. Run engine a couple of minutes before you put engine
under load.

7. With the engine fully warmed up, release the parking
brake and test the brakes for proper adjustment as you
move forward. Adjust the brakes as necessary.

80 TROUBLESHOOTING

TROUBLESHOOTING

ENGINE TROUBLESHOOTING

If the engine is not performing correctly, refer to the table below for the cause.

If Probable cause

Engine is difficult to start. A Fuel tank or fuel filter is clogged by dirt.

A Air or water in the fuel system.

A In winter, oil viscosity increases, and engine cranks

slowly.

A Battery is discharged.

Insufficient engine power. A Air cleaner element is clogged.

A Insufficient fuel flow or quality.

Engine stops suddenly. A Insufficient fuel.

Exhaust fumes are colored. A Fuel quality is poor.

Black smoke is emitted from the muffler during operation;
power output is lowered.

Bluish white smoke is emitted from the muffler during
operation.

Engine will not idle. A Fuel filter is clogged.

Engine overheats. A [For GR2120, GR2120AU] Low coolant level.

If you have any questions, contact your local KUBOTA Dealer.

A Air cleaner element clogged.

A Too much engine oil.

A [For GR2120, GR2120AU] Loose or defective fan belt.

A [For GR2120, GR2120AU] Coolant flow route corroded.

A [For GR2020G] Cooling fan trouble.

BATTERY TROUBLESHOOTING

If Probable cause

Starter does not function. A Battery discharged.

A Poor terminal connection.

A Battery life expired.

When viewed from top, the top of plates looks whitish. A Electrolyte level is low.

A Battery was used too much without recharging.

Recharging is impossible. A Battery life expired.

Terminals are severely corroded and heat up. A Poor terminal connection or stained terminal.

Battery electrolyte level drops rapidly. A There is a crack or pin holes in the electrolytic cells.

A Charging system trouble.

If you have any questions, contact your local KUBOTA Dealer.

MACHINE TROUBLESHOOTING

If Probable cause

Machine operation is not smooth. A Hydrostatic transmission oil is low.

Machine does not move while engine is running. A Parking brake is on.

A Transmission oil is insufficient.

81TROUBLESHOOTING

Machine moves when speed control pedal is not
depressed.
(Engine is operated.)

Larger turn radius or turf damage by inside rear axle issue. A Glide steer system is not correctly adjusted.

If you have any questions, contact your local KUBOTA Dealer.

A Hydrostatic neutral system is not correctly adjusted.

82 TROUBLESHOOTING

MOWER TROUBLESHOOTING

If Probable cause

Discharge chute plugged. A Grass too wet.

A Grass too long.
A Cutting too low.
A Engine rpm too low.
A Ground speed too fast.
A Restricted airflow.

Streaking of uncut grass. A Ground speed too fast.

A Engine rpm too low.
A Grass too long.
A Blades dull or damaged.
A Debris in mower deck.

Uneven cut. A Mower deck not level.

A Ground speed too fast.
A Blades dull.
A Blades worn.
A Tire inflation.
A Mower rollers not adjusted correctly.

Blades scalping grass. A Cutting height too low.

A Blades speed too fast.
A Ridges in terrain.
A Rough or uneven terrain.
A Bent blade(s).
A Low tire inflation.
A Anti-scalp rollers not adjusted correctly.

Belt slipping. A Belt tension incorrect.

A Mower deck plugged.
A Debris in pulleys.
A Worn belt.

Excessive vibration. A Debris on mower deck or in pulleys.

A Damaged mower belt.
A Damaged pulleys.
A Pulleys out of alignment.
A Blades out of balance.

Mower loads down machine. A Engine rpm too low.

A Ground speed too fast.
A Debris wrapped around mower spindles.

Grass tips are jagged and turn grayish brown. A Blades dull.

A Blades worn.
A Mower deck is not level.

If you have any questions, contact your local KUBOTA Dealer.

INDEX

83INDEX

Air Cleaner Element .......................................51

Air Cleaner Element .......................................71

Air Cleaner Paper Element.............................58

Amount of Fuel and Refueling........................43

Anti-freeze ......................................................72

Battery Condition............................................57

Blade ..............................................................74

Block Heater (Option).....................................14

Brake ..............................................................61

bulbs...............................................................74

Carbon Canister Air Filter...............................52

Cold Weather Starting ....................................14

Coolant Level .................................................46

Cruise Control Device ....................................20

Cutting Height Control Dial.............................25

Directions for Use of Power Steering .............23

Easy Checker (TM) ........................................21

Engine Break-in..............................................17

Engine Breather Hose ....................................73

Engine Oil.......................................................64

Engine Oil Filter Cartridge..............................63

Engine Oil Level .............................................42

Engine Overheating Precautions....................21

Engine Shroud................................................68

Engine Shroud Panel .....................................59

Engine Start System.......................................49

Engine Stop (By manual) ...............................15

Fan Drive Belt Tension...................................61

Flush Cooling System and Changing

Coolant ...........................................................71

Front Axle Case Oil ........................................70

Front Axle Pivot ..............................................68

Fuel Filter .......................................................69

Fuel Filter .......................................................71

Fuel Gauge.....................................................22

Fuel Injection Nozzle (Injection Pressure)...... 71

Fuel Lines and Fuel Vapor Lines....................73

Fuel Lines, Fuel Vapor Lines and Fuel Filter..59

Fuel System ...................................................76

Fuses..............................................................73

Gear Box Oil...................................................62

Gear Box Oil Level .........................................53

Glide Steer .....................................................24

Greasing.........................................................53

Head Light Switch ..........................................18

Hourmeter ......................................................22

Hydraulic Hose ...............................................66

Hydraulic Hose ...............................................73

Hydraulic Lift Lever........................................ 19

Immediately Stop the Engine if:..................... 21

Inflation Pressure........................................... 31

Injection Pump............................................... 71

Intake Air Line................................................ 68

Intake Air Line................................................ 73

Key Switch..................................................... 12

KRA system Normal Operating Mode............ 27

KRA system Override Mode .......................... 28

Lubricating All Grease Fittings....................... 47

Lubricating Oil for New Machines.................. 17

Machine Break-in........................................... 17

Mounting the Mower Deck............................... 7

Movable Parts................................................ 48

Mower Belt Replacement .............................. 76

Mower Gear Box Oil Seal .............................. 73

Oiling ............................................................. 54

OPC System.................................................. 50

Operator's Seat.............................................. 18

Parking .......................................................... 23

Parking Brake ................................................ 19

Precleaner and Air Cleaner Paper Element .. 48

PTO Control System...................................... 50

PTO Lever ..................................................... 28

Radiator and Screen to Prevent

Overheating ................................................... 44

Radiator Hose................................................ 73

Radiator Hose and Clamp ............................. 66

Spark Plug Condition & Gap.......................... 68

Speed Control Pedal ..................................... 20

Stopping ........................................................ 21

Throttle Lever ................................................ 19

Throttle Lever and Choke Lever .................... 13

Tire Pressure ................................................. 45

Transmission Fluid ........................................ 69

Transmission Fluid Level............................... 46

Transmission Oil Filter Cartridge ................... 65

Transmission Strainer.................................... 70

Warm-up and Transmission Oil in the Low

Temperature Range ...................................... 15