Scag Power Equipment Turf Tiger Diesel Powered STT61V-25KBD User manual

PART NO. 03249
PRINTED 7/2008
PRINTED IN USA
© 2008
Scag Power Equipment
Division of Metalcraft of Mayville, Inc.
Congratulations on owning a Scag mower! This manual contains the operating
instructions and safety information for your Scag mower. Reading this manual
can provide you with assistance in maintenance and adjustment procedures to
keep your mower performing to maximum efciency. The specic models that
this book covers are listed on the inside cover. Before operating your machine,
please read all the information enclosed.
OPERATOR’S
MANUAL
TurfTiger
DieselPowered
Model: STT-28CAT
STT61V-25KBD

WARNING
FAILURETO FOLLOW SAFE OPERATING PRACTICES MAY RESULT
IN SERIOUS INJURY OR DEATH.
Read this manual completely as well as other manuals that came with your mower.•
DO NOT operate on steep slopes.To check a slope, attempt to back up it (with the• cutter deck down). If the machine can back up the slope without the wheels slipping,
reduce speed and use extreme caution.
Under no circumstances should the machine be operated on slopes greater than 15• degrees. ALWAYS FOLLOW OSHA APPROVED OPERATION.
DO NOT mow on wet grass.Wet grass reduces traction and steering control.•
Keep all shields in place, especially the grass discharge chute.•
Before performing any maintenance or service, stop the machine and remove the• spark plug wire and ignition key.
If a mechanism becomes clogged, stop the engine before cleaning.•
Keep hands, feet and clothing away from power-driven parts.•
Keep others off the mow• er (only one person at a time)
REMEMBER -YOUR MOWER IS ONLY AS SAFE ASTHE OPERATOR!
HAZARD CONTROL AND ACCIDENT PREVENTION ARE DEPENDENT UPON THE AWARENESS,
CONCERN, PRUDENCE, AND PROPER TRAINING OF THE PERSONNEL INVOLVED IN THE
OPERATION,TRANSPORT, MAINTENANCE, AND STORAGE OFTHE EQUIPMENT.
This manual covers the operating instructions and illustrated parts list for:
STT61V-28CAT-SS with a serial number of E2000001 to E2099999
STT-28CAT-SS with a serial number of E2100001 to E2199999
STT61V-25KBD-SS with a serial number of E3800001 to E3899999
SMT-72V with a serial number of E2300001 to E2399999
Always use the entire serial number listed on the serial number tag when referring to this product.

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Table of Contents
Table of Contents
GENERAL INFORMATIONSECTION 1 - ...................................................................................1
1.1 INTRODUCTION...........................................................................................................................................1
1.2 DIRECTION REFERENCE...........................................................................................................................1
1.3 SERVICINGTHE ENGINE AND DRIVETRAIN COMPONENTS.................................................................1
1.4 SYMBOLS ....................................................................................................................................................2
SAFETY INFORMATIONSECTION 2 - ......................................................................................3
2.1 INTRODUCTION...........................................................................................................................................3
2.2 SIGNALWORDS..........................................................................................................................................3
2.3 BEFORE OPERATION CONSIDERATIONS................................................................................................3
2.4 OPERATION CONSIDERATIONS................................................................................................................4
2.5 ROLL-OVER PROTECTION SYSTEM.........................................................................................................6
2.6 MAINTENANCE CONSIDERATIONS & STORAGE....................................................................................8
2.7 USING A SPARK ARRESTOR.....................................................................................................................8
2.8 SAFETY AND INSTRUCTIONAL DECALS.................................................................................................9
SPECIFICATIONSSECTION 3 - ..............................................................................................10
3.1 ENGINE ......................................................................................................................................................10
3.2 ELECTRICAL .............................................................................................................................................10
3.3 POWER HEAD ...........................................................................................................................................10
3.4 CUTTER DECK ..........................................................................................................................................11
3.5 HYDRAULIC SYSTEM ...............................................................................................................................11
3.6WEIGHTS AND DIMENSIONS...................................................................................................................11
3.7 PRODUCTIVITY .........................................................................................................................................11
OPERATING INSTRUCTIONSSECTION 4 - ...........................................................................12
4.1 CONTROLS AND INSTRUMENT IDENTIFICATION .................................................................................12
4.2 SAFETY INTERLOCK SYSTEM................................................................................................................13
4.3 INITIAL RUN-IN PROCEDURES (FIRST DAY OF USE OR APPROXIMATELY 10 HOURS)...................13
4.4 STARTINGTHE ENGINE ...........................................................................................................................14
4.5 GROUNDTRAVEL AND STEERING.........................................................................................................14
4.6 ENGAGINGTHE DECK DRIVE (CUTTER BLADES)................................................................................15
4.7 HILLSIDE OPERATION..............................................................................................................................16
4.8 PARKINGTHE MOWER.............................................................................................................................16
4.9 AFTER OPERATION..................................................................................................................................16
4.10 REMOVING CLOGGED MATERIAL ........................................................................................................16
4.11 MOVING MOWER WITH ENGINE STOPPED..........................................................................................17
4.12 RECOMMENDATIONS FOR MOWING....................................................................................................17
4.13 ADJUSTING CUTTING HEIGHT..............................................................................................................17
4.14 ADJUSTINGTHE HEIGHT ADJUST PEDAL ..........................................................................................18
4.15 ADJUSTINGTHE STEERING LEVERS...................................................................................................18
4.16TOWING (OPTIONAL HITCH ACCESSORY)...........................................................................................19
TROUBLESHOOTING CUTTING CONDITIONSSECTION 5 - ...............................................20

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Table of Contents
ADJUSTMENTSSECTION 6 - .................................................................................................23
6.1 PARKING BRAKE ADJUSTMENT ............................................................................................................23
6.2TRAVEL ADJUSTMENTS ..........................................................................................................................24
6.3THROTTLE CONTROL AND CHOKE ADJUSTMENTS............................................................................25
6.4 BELT ADJUSTMENT .................................................................................................................................25
6.5 BELT ALIGNMENT.....................................................................................................................................26
6.6 CUTTER DECK ADJUSTMENTS ..............................................................................................................26
6.7 ELECTRIC CLUTCH ADJUSTMENT.........................................................................................................29
MAINTENANCESECTION 7 - ..................................................................................................30
7.1 MAINTENANCE CHART - RECOMMENDED SERVICE INTERVALS ......................................................30
7.2 LUBRICATION............................................................................................................................................31
7.3 HYDRAULIC SYSTEM ...............................................................................................................................33
7.4 ENGINE OIL ...............................................................................................................................................34
7.5 ENGINE FUEL SYSTEM............................................................................................................................34
7.6 ENGINE AIR CLEANER.............................................................................................................................35
7.7 BATTERY....................................................................................................................................................35
7.8 DRIVE BELTS.............................................................................................................................................36
7.9 CUTTER BLADES......................................................................................................................................36
7.10TIRES........................................................................................................................................................37
7.11 CUTTER DECK GEARBOX .....................................................................................................................38
7.12 COOLING SYSTEM .................................................................................................................................38
7.13 BODY, DECK, AND UPHOLSTERY.........................................................................................................39
ILLUSTRATED PARTS LISTSECTION 8 - ..............................................................................40
8.1 SCAG APPROVED ATTACHMENTS AND ACCESSORIES......................................................................40
NOTES..............................................................................................................................................................41
61V & 72V CUTTER DECK..............................................................................................................................42
CUTTER DECK CONTROLS...........................................................................................................................44
SHEET METAL COMPONENTS......................................................................................................................46
STT ROLL-OVER PROTECTION SYSTEM -WITH SUSPENSION SEAT......................................................48
DECK DRIVE COMPONENTS.........................................................................................................................50
ENGINE & ATTACHING PARTS - CAT DIESEL ..............................................................................................52
RADIATOR & ATTACHING PARTS - CAT DIESEL..........................................................................................54
ENGINE & ATTACHING PARTS - KUBOTA DIESEL ......................................................................................56
BRAKE AND STEERING COMPONENTS ......................................................................................................58
FUEL AND HYDRAULIC SYSTEM - CAT DIESEL..........................................................................................60
FUEL AND HYDRAULIC SYSTEM - KUBOTA DIESEL..................................................................................62
BDP-16A HYDRAULIC PUMP ASSEMBLY WITH COOLING FAN.................................................................64
ELECTRICAL SYSTEM - CAT DIESEL ...........................................................................................................66
ELECTRICAL SYSTEM - KUBOTA DIESEL ...................................................................................................68
REPLACEMENT DECALS AND INFORMATION PLATES .............................................................................70
ELECTRICAL SCHEMATIC - CAT DIESEL.....................................................................................................72
ELECTRICAL SCHEMATIC - KUBOTA DIESEL.............................................................................................73
LIMITEDWARRANTY - COMMERCIAL EQUIPMENT......................................................Following Section 8

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Section 1
INTRODUCTION1.1
Your mower was built to the highest standards in the
industry. However, the prolonged life and maximum
efficiency of your mower depends on you following the
operating, maintenance and adjustment instructions in
this manual.
If additional information or service is needed, contact your
Scag Power Equipment Dealer.
We encourage you to contact your dealer for repairs. All
Scagdealers are informed of the latestmethodstoservice
this equipment and provide prompt and efficient service in
the field or at their service shop. They carry a full line of
Scag service parts.
THEREPLACEMENTOFANYPARTONTHISPRODUCT
BYOTHERTHANTHEMANUFACTURER'SAUTHORIZED
REPLACEMENT PART MAY ADVERSELY AFFECTTHE
PERFORMANCE, DURABILITY OR SAFETY OF THIS
PRODUCT.
USEOFOTHERTHANORIGINALSCAGREPLACEMENT
PARTSWILLVOIDTHE WARRANTY.
When ordering parts, always give the model and serial
number of your mower.The serial number plate is located
where shown in Figure 1-1.
SERIAL NUMBER
PLATE LOCATION
R
MODEL
SERIAL
Division of Metalcraft of Mayville, Inc.
Mayville, Wisconsin 53050
Patents Issued and Pending
MANUFACTURED UNDER ONE OR MORE
OF THE FOLLOWING PATENTS:
PATENTS PENDING
4,487,006
4,885,903
4,920,733
4,967,543
4,991,382
4,998,948
5,118,617
5,826,416
5,832,708
5,865,018
Mower Serial Number Plate LocationFigure 1-1.
GENERAL INFORMATION
USE ONLY SCAG APPROVED ATTACHMENTS AND
ACCESSORIES.
Attachmentsandaccessoriesmanufacturedbycompanies
other thanScagPower Equipmentarenotapproved foruse
on this machine.See Section 8-1.
WARNING
Forpictorialclarity,someillustrationsand figures
inthismanualmayshowshields,guardsorplates
open orremoved.Undernocircumstancesshould
your mower be operated without these devices
in place.
Allinformationis based uponproductinformation available
at the time of approval for printing.Scag Power Equipment
reserves the right to make changes at any time without
notice and without incurring any obligation.
DIRECTION REFERENCE1.2
The“Right”and“Left”,“Front”and“Rear”of the machineare
referenced from the operator’s right and left when seated
in the normal operating position and facing the forward
travel direction.
SERVICINGTHE ENGINE AND DRIVE1.3
TRAIN COMPONENTS
The detail servicing and repair of the engine, hydraulic
pumps and gearboxes are not covered in this manual;
only routine maintenance and general service instructions
are provided. For service of these components during
the limited warranty period, it is important to contact your
Scag dealer or find a local authorized servicing agent of
thecomponentmanufacturer.Anyunauthorized work done
on these components during the warranty period may void
your warranty.

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Section 1
SYMBOLS1.4
SYMBOL DESCRIPTION SYMBOL DESCRIPTION
Choke Transmission
Parking Brake
48071S
Spinning Blade
On/Start Spring Tension on Idler
Off/Stop Oil
Falling Hazard Thrown Object Hazard
Fast Slow
Continuously Variable - Linear Cutting Element - Basic Symbol
481039S
Pinch Point Cutting Element - Engage
Hour meter/Elapsed Operating Hours Cutting Element - Disengage
STT MODELS
Seat must be installed under the seat
hold down bracket during installation.
Failure to secure the seat under the hold
down bracket could result in serious
injury or death in a roll over.
CE Mark
Thrown Object Hazard
Keep Bystanders Away
Read Operator's Manual

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Section 2
INTRODUCTION2.1
Your mower is only as safe as the operator. Carelessness
or operator error may result in serious bodily injury
or death. Hazard control and accident prevention are
dependent upon the awareness, concern, prudence, and
proper training of the personnel involved in the operation,
transport,maintenanceandstorageof theequipment.Make
sure every operator is properly trained and thoroughly
familiar with all of the controls before operating the
mower.The owner/user can prevent and is responsible for
accidentsor injuries occurringtothemselves,other people
or property.
READ THIS OPERATOR’S MANUAL BEFORE
ATTEMPTINGTO STARTYOUR MOWER.
A replacement manual is available from your authorized
Scag Service Dealer or by contacting Scag Power
Equipment,Service Department at P.O.Box152, Mayville,
WI 53050 or contact us via the Internet at www.scag.com.
The manual for this machine can be downloaded by using
the model and serial number or use the contact form to
make your request. Please indicate the complete model
and serial number of your Scag product when requesting
replacement manuals.
SIGNALWORDS2.2
This symbol means “Attention! Become Alert! Your
Safety is Involved!" Thesymbolisusedwiththe following
signal words to attract your attention to safety messages
found on the decals on the machine and throughout this
manual. The message that follows the symbol contains
important information about safety. To avoid injury and
possibledeath,carefullyreadthemessage!Besuretofully
understand the causes of possible injury or death.
SIGNALWORD:
It is a distinctive word found on the safety decals on the
machine and throughout this manual that alerts the viewer
to the existence and relative degree of the hazard.
DANGER
The signal word “DANGER” denotes that an extremely
hazardous situation exists on or near the machine that
couldresultinhighprobabilityofdeathorirrepairableinjury
if proper precautions are not taken.
WARNING
The signal word“WARNING”denotes that a hazard exists
on or near the machine that can result in injury or death if
proper precautions are not taken.
CAUTION
Thesignalword“CAUTION”isareminderof safetypractices
on or near the machine that could result in personal injury
if proper precautions are not taken.
Your safety and the safety of others depends significantly
upon your knowledge and understanding of all correct
operating practices and procedures of this machine.
BEFORE OPERATION2.3
CONSIDERATIONS
NEVER allow children to operate this riding mower.1. Do not allow adults to operate this machine without
proper instructions.
Do not mow when children and/or others are2. present. Keep children out of the mowing area and
in the watchful care of a responsible adult other than
the operator. Be alert and turn machine off if a child
enters the area.
DO NOT allow children to ride or play on the3. machine, it is not a toy.
Clear the area to be mowed of objects that could be4. picked up and thrown by the cutter blades.
DO NOT carry passengers.5.
DO NOT operate the machine under the influence of6. alcohol or drugs.
SAFETY INFORMATION

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Section 2
If the operator(s) or mechanic(s) cannot read English7. or Spanish, it is the owner's responsibility to explain
this material to them.
DO NOT wear loose fitting clothing. Loose clothing,
8. jewelry or long hair could get tangled in moving
parts.Do not operate the machine wearing shorts;
always wear adequate protective clothing including
long pants.Wearing safety glasses, safety shoes and
a helmet is advisable and is required by some local
ordinances and insurance regulations.
WARNING
Always wear hearing protection. Operating this
machine over prolonged periods of time can
cause loss of hearing.
Keep the machine and attachments in good9. operating condition.Keep all shields and safety
devices in place.If a shield, safety device or decal
is defective or damaged, repair or replace it before
operating the machine.
WARNING
Thismachineisequippedwithaninterlocksystem
intended to protect the operator and others from
injury. This is accomplished by preventing the
engine from starting unless the deck drive is
disengaged,the parking brake is on,the steering
control levers are in the neutral position and the
operator is in the seat.The system shuts off the
engineiftheoperatorleavestheseatwiththedeck
drive engaged and/or the steering control levers
are not in the neutral position and the parking
brake is not engaged. Never operate equipment
with the interlock system disconnected or
malfunctioning.
Be sure the interlock switches are functioning10. correctly.
Fuel is flammable;handle it with care.Fill the fuel11. tank outdoors.Never fill it indoors. Use a funnel or
spout to prevent spillage.Clean up any spillage
before starting the engine.
DO NOT add fuel to a running or hot engine.Allow
12. the engine to cool for several minutes before adding
fuel. Never fuel indoors or inside enclosed trailers.
Keep flammable objects (cigarettes, matches, etc.),13. open flames and sparks away from the fuel tank and
fuel container. Use only approved containers.
Equipment must comply with the latest requirements14. per SAE J137 and/or ANSI/ASAE S279 when driven
on public roads.
- NOTE -
If the mower is driven on public roads, it must
comply with state and local ordinances as well as
SAE J137and/or ANSI/ ASAE S279requirements.
Contact your local authorities for regulations and
equipment requirements.
Do not operate without the side discharge chute15. installed and in the down position or with an optional
grass catcher or mulch plate completely installed.
Check the blade mounting bolts at frequent intervals16. for proper tightness.
Make sure all hydraulic fluid connections are tight17. and all hydraulic hoses and lines are in good
condition before starting the machine.
OPERATION CONSIDERATIONS2.4
Know the function of all controls and how to stop1. quickly.
WARNING
DONOToperate on steepslopes.To checkaslope,
attempt to back up it (with the cutter deck down).
If the machine can back up the slope without the
wheels slipping, reduce speed and use extreme
caution. Under no circumstances should the
machine be operated on slopes greater than 15
degrees. ALWAYS FOLLOW OSHA APPROVED
OPERATION.
Reduce speed and exercise extreme caution on2. slopes and in sharp turns to prevent tipping or loss
of control. Be especially cautious when changing
directions on slopes.
To prevent tipping or loss of control, start and stop3. smoothly, avoid unnecessary turns and travel at
reduced speed.

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Section 2
When using any attachment, never direct the4. discharge of material toward bystanders or allow
anyone near the machine while in operation.
Before attempting to start the engine, with the5. operator in the seat, disengage power to the cutter
deck, place the steering control levers in the neutral
position and engage the parking brake.
If the mower discharge ever plugs, shut off the6. engine, remove the ignition key, and wait for all
movement to stop before removing the obstruction.
WARNING
DO NOT use your hand to dislodge the clogged
discharge chute. Use a stick or other device to
remove clogged material after the engine has
stopped running and the blades have stopped
turning.
Be alert for holes, rocks, roots and other hidden7. hazards in the terrain. Keep away from any drop-
offs.Beware of overhead obstructions (low limbs,
etc.), underground obstacles (sprinklers, pipes, tree
roots, etc.).Cautiously enter a new area. Be alert for
hidden hazards.
Disengage power to cutter deck before backing up.8. Do not mow in reverse unless absolutely necessary
and then only after observation of the entire area
behind the mower. If you must mow in reverse,
maintain a constant lookout to the rear of the
machine and mow slowly.
DO NOT turn sharply. Use care when backing up.9.
Disengage power to cutter deck before crossing10. roads, walks or gravel drives.
Mow only in daylight or good artificial light.11.
NEVER raise the deck with the blades engaged.12.
Take all possible precautions when leaving the13. machine unattended, such as disengaging the
mower, lowering the attachments, setting the parking
brake, stopping the engine, and removing the key.
Disengage power to the attachments when14. transporting or when not in use.
The machine and attachments should be stopped15. and inspected for damage after striking a foreign
object, and damage should be repaired before
restarting and operating the machine.
CAUTION
Do not touch the engine or the muffler while the
engine is running or immediately after stopping.
These areas may be hot enough to cause a
burn.
DANGER
DO NOT run the engine inside a building or
a confined area without proper ventilation.
Exhaust fumes are hazardous and contain
carbon monoxide which can cause brain injury
and death.
Keep hands and feet away from cutter blades and16. moving parts.Contact can injure.
Transport the mower using a heavy duty trailer17. or truck.Insure the trailer or truck has all of the
necessary lighting and markings as required by
laws, codes, and ordinances.Secure a trailer with a
safety chain.
Be cautious when loading and unloading onto18. trailers or trucks.Use only a full width ramp. Ramp
angle should be no more than 15 degrees. Back up
the ramp and drive down forward.
When transporting the mower, make sure the park19. brake is engaged, the steering control levers are in
the neutral position, the engine is off with the key
removed, and the wheels have been blocked.
Tie the mower down securely using straps, chains,20. cable, or ropes. Both front and rear straps must be
directed down and outward from machine.
Use care when approaching blind corners, shrubs,21. trees, or other objects that may obscure vision.
NEVER leave the machine running unattended.22.

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Section 2
Lower the roll bar only when absolutely necessary.
To lower the roll bar, loosen the tension knob on both1. the left hand and right hand bar. See Figure 2-1.
Remove the hairpin cotter pins and remove the two2. (2) lock pins.See Figure 2-2.
Lower the roll bar to the down position.3.
To raise the roll bar, lift the bar to the upright4. position.
Install the two (2) lock pins through the hole, secure5. with the two (2) hairpin cotter pins and tighten the
tension knobs.See Figure 2-2. Remove the seat belt
from the retainer brackets.
UPRIGHT AND
LOCKED POSITION
TENSION
KNOBS
Foldable Roll-Over Protection SystemFigure 2-1.
TENSION
KNOB
HAIR PIN
LOCK PIN
ROPS HingeFigure 2-2.
The potential exposure of the seat belt to severe
environmentalconditionsmakeitcrucialtoinspecttheseat
belt system regularly.
ROLL-OVER PROTECTION SYSTEM2.5
WARNING
Keep the roll bar in the raised and locked position
and the seat belt securely fastened during
operation. Failure to do so could cause serious
injury or loss of life.
This mower has been designed for good traction and
stabilityundernormalmowingconditions. However,caution
mustbeusedwhentravelingonslopes,especiallywhenthe
grass is wet.Do not mow on wet grass.Wet grass reduces
traction and steering control.
Any or all parts of the Roll-Over Protection System MUST
NOT be removed.Failure to adhere to this guideline could
result in injury or death.
WARNING
There is no roll-over protection when the roll bar
is in the down position.
Lower the roll bar only when absolutely
necessary.
Raise the roll bar as soon as clearance permits.
DO NOT wear the seat belt when the roll bar is in
the down position.
ALWAYS wear seat belt when roll bar is in the up
position.
Operate the machine smoothly,no sudden turns,
starts or stops.
Check theareacarefullybeforemowingforproper
overhead clearance (i.e. branches, doorways,
etc.).
DO NOT contact any overhead object with the
roll bar.

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Section 2
It is recommended that the seat belt be inspected on a
daily basis for signs of damage. Any seat belt system that
shows cuts, fraying, extreme or unusual wear, significant
discolorationduetoUVexposure, dirtorstiffness,abrasion
to the seat belt webbing, or damage to the buckle, latch
plate, hardware or any other obvious problem should be
replaced immediately.
WARNING
Failure to properly inspect and maintain the seat
belt can cause serious injury or loss of life.
Check the full length of the seat belt webbing for1. cuts, wear, fraying, dirt and stiffness. See Figure 2-3.
Check the seat belt webbing in areas exposed to2. ultra violet rays from the sun or extreme dust or
dirt. If the original color of the webbing in these
areas is extremely faded and/or is packed with dirt,
the physical strength of this webbing may have
deteriorated. If this condition exists, replace the seat
belt system.
Check the buckle and latch for proper operation
3. and determine if the latch plate is excessively worn,
deformed, or if the buckle is damaged or cracked.
See Figure 2-3.
INSPECTWEBBING
INSPECT BUCKLE
& LATCH
Seat Belt InspectionFigure 2-3.
WARNING
Reduce speed when turning,operating on slopes,
slick or wet surfaces. Allow extra distance to
stop.
Stay off of slopes too steep for safe operation.
To check a slope, attempt to back up it (with the
cutter deck down). If the machine can not back
up the slope without the wheels slipping, do not
operate the machine on this slope. Under no
circumstances should the machine be operated
on slopes greater than 15 degrees.
DO NOT mow near drop-offs, ditches or
embankments.The machine could suddenly roll
over if a wheel goes over the edge or if the edge
caves in.
Operate the machine smoothly, no sudden turns,
starts or stops on a slope.
NEVER tow on slopes. The weight of the towed
equipment may cause loss of traction and loss
of control.
DO NOT permit untrained personnel to operate
the machine.
Be cautious when loading and unloading onto
trailers or trucks.
Use only a full width ramp.
Ramp angle should be no more than 15
Degrees.
Back up the ramp and drive down forward.

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Section 2
MAINTENANCE CONSIDERATIONS &2.6
STORAGE
Never make adjustments to the machine with the1. engine running unless specifically instructed to do
so. If the engine is running, keep hands, feet, and
clothing away from moving parts.
Disengage drives, lower implement, set parking
2. brake, stop engine and remove key or disconnect
spark plug wire to prevent accidental starting of the
engine when servicing or adjusting the machine.
Wait for all movement to stop before adjusting,
cleaning or repairing.
Disconnect battery or remove spark plug wire before3. making any repairs. Disconnect the negative terminal
first and the positive last.Reconnect the positive first
and the negative last.
Keep all nuts, bolts and screws tight, to ensure the
4. machine is in safe working condition. Check blade
mounting bolts frequently to be sure they are tight.
Do not change the engine governor settings or5. overspeed the engine. See the engine operator's
manual for information on engine settings.
To reduce fire hazard, keep the cutting units, drives,6. muffler and engine free of grass, leaves, excessive
grease, oil and dirt.
Park the machine on level ground and engage the
7. parking brake.
NEVER allow untrained personnel to service the
8. machine.
Use care when checking blades. Use a Blade Buddy,9. wrap the blade(s) or wear gloves and USE CAUTION
when servicing blades. Only replace blades.NEVER
straighten or weld blades.
Keep all parts in good working condition. Replace all10. worn or damaged decals.
Use jack stands to support components when11. required.
Carefully release pressure from components with
12. stored energy.
WARNING
Hydraulic fluid is under high pressure. Keep
body and hands away from pinholes or nozzles
that eject hydraulic fluid under high pressure.
If you need service on your hydraulic system,
please see your authorized Scag dealer. If
hydraulic fluid is injected into the skin,it must be
surgicallyremovedwithina fewhoursbya doctor
or gangrene may result.
Let the engine cool before storing.13.
DO NOT store the machine near an open flame.14.
Shut off fuel while storing or transporting.15.
DO NOT store fuel near flames or drain indoors.16.
Charge batteries in an open, well ventilated area,17. away from spark and flames.Unplug charger before
connecting or disconnecting from battery.Wear
protective clothing and use insulated tools.
USING A SPARK ARRESTOR2.7
The engine in this machine is not equipped with a spark
arrestor muffler. It is in violation of California Public
ResourceCodeSection4442 touseor operatethisengine
on or near any forest covered, brush covered or grass
covered land unless the exhaust system is equipped with
a spark arrestor meetingany applicable local or state laws.
Otherstatesorfederalareasmayhave similarlaws.Check
withyourstateor localauthoritiesforregulationspertaining
to these requirements.

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Section 2
SAFETY AND INSTRUCTIONAL DECALS2.8
390S0150F
483395
483406
483407
483402
483444
483154
WARNING
INSTALL BELT COVER BEFORE
OPERATING MACHINE
READ OPERATOR'S MANUAL
481568
FORWARD
REVERSE
FR483429
483633
!CAUTION
DIESEL FUEL ONLY
Avoid injury from burns.
Shut off engine before
removing fuel tank cap.
483395
483154
!
WARNING
483444
START / DRIVE PROCEDURE
AVOID SERIOUS INJURY OR DEATH
483425

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Section 3
SPECIFICATIONS
ENGINE3.1
General Type ....................................................................................................Heavy Duty Industrial/Commercial Diesel
Brand.......................................................................................................................CAT 28HP Diesel [Spec.#307-9829]
Kubota 25HP Diesel [Spec. #D902-E2B-KAE-2 (1G447-00000)]
Model............................................................................................................................................................... CAT - C1.1
Kubota - D902
Horsepower.................................................................28 HP at 3200 RPM (Model STT61V-28CAT-SS, STT-28CAT-SS)
25 HP at 3600 RPM (Model STT61V-25KBD-SS)
Type.....................................................................................4 Stroke Diesel, 3 Cylinder, Horizontal Shaft, Liquid-Cooled
Displacement............................................................................................................................898 cc Kubota, 1.13L.Cat
Cylinders..........................................................................................................................................................................3
Governor..............................Mechanical Type with Variable Speed Control Set At 3200 RPM - CAT, 3670 RPM -Kubota
Idle Speed ........................................................................................................................................................1200 RPM
Fuel Pump.......................................................................................................Electric Fuel Pump with in-line filter - CAT
Injection Pump, Bosch MD Mini Type with in-line fuel filter - Kubota
Fuel......................................................................................................... Diesel Fuel with a minimum cetane rating of 40
Oil Pump Group............................................................................... Pressure Lube, 5.2 U.S. Quarts with Oil Filter - CAT
Positive Displacement Gerotor™ Oil Pump with Oil Filter - Kubota
Starter............................................................................................................Electric Starting with Solenoid Shift Starter
Belts:................................................................................................................Kevlar cord.Self-adjusting, Self-tightening
Deck Drive Belt................................................................................................................Scag Part Number - 481460
Pump Drive Belt ....................................................................................................Scag Part Number - 483735 - CAT
Scag Part Number - 483678 - Kubota
ELECTRICAL3.2
Battery.....................................................................................................................12Volt, Maintenance Free (525CCA)
Charging System............................................................................................................................................... Alternator
Charging Output.......................................................................................................................................12 Volt, 40 Amp
System Polarity.......................................................................................................................................Negative Ground
Starter.................................................................. 12 Volt Electric Ring Gear Type, Key and Solenoid Operated Interlock
Switches.....................................................................Seat, Neutral Control, Mower Engagement (BBC), Parking Brake
Instrument Panel ............................................Volt Meter, Key Switch, Throttle Lever, BBC Switch, Temperature Gauge,
Fuses, Safety Start Module, Oil Pressure Gauge, Glow Plug Indicator
Fuses..................................................................................................................Two (1) 20 Amp, (1) 50 Amp Resettable
POWER HEAD3.3
Drive System................Hydraulic Drive with Two Variable Displacement Pumps and Two Cast-iron High Torque Motors
Hydrostatic Pumps .......................................................................Two Hydro-Gear™ 16cc Pumps with Dump Valves for
movement without running the engine and pressure relief valves
Drive Wheel Motors...........................................Two Hydro-Gear Model 18E, 18 cu. Inch Cast-Iron High-Torque Motors
Steering/Travel Control....................................................................................Twin Lever Fingertip Steering Control with
Individual Control to Each Wheel with Gas Spring Dampers
Parking Brake...................................................................Lever Actuated Linkage to Brakes on Both Drive Wheel Axles
Wheels:
(2) Front Caster............................................................................................................................. 13 X 6.00 Flat Free
(2) Drive............................................................. 24X12.0X12 Four-Ply Pneumatic Tubeless, Radius Edge, 61" & 72"
Tire Pressure:
Front Caster....................................................................................................................................................Flat Free
Drive..................................................................................................................................................................12 PSI
Fuel Tank.......................................10-Gallon Seamless Polyethylene Tank with large opening and Fuel Gauge Fill Cap
Seat..........................................................................................................................................Padded, Suspension Seat

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Section 3
Travel Speed:
Forward .................................................................................................................................................................0-12
Reverse..........................................................................................................................................................0-6 MPH
-NOTE- The machine will travel at 12mph for transport purposes. For best cutting performance the forward travel
speed should be adjusted depending upon the cutting conditions.
CUTTER DECK3.4
Type...........................Floating, Adjustable, Anti-scalping, Hybrid Design Combines Out-front and Belly-mount Designs
Construction ..........................10-gauge steel reinforced with 7-gauge (3/16") Support Plate. 7-gauge (3/16") deck skirt.
True Cutting Width:
61V........................................................................................................................................................61" (155.0 cm)
72V........................................................................................................................................................72" (182.9 cm)
Cutting Height Adjustment.......Foot-Operated Lever Adjustment from Operator's Seat, 1.00" to 6.00" in 1/4"increments
Cutter Blades..................................................................................0.197 Thick, Milled Edge, Wear Resistant Marbain™
61V.............................................................................................................................................. Three (3) 21" blades
72V........................................................................................................................................... Three (3) 24.5" blades
Blade Engagement......................................... Electric Blade Engagement Clutch with Control Panel Switch Connected
to the Cutter Deck Gearbox through a Drive Shaft.
Discharge Opening......................................Extra Wide 11.5" Discharge Opening with Spring Loaded Discharge Chute
Discharge Chute...................................................................................................Black, Polypropylene (Plastic), Flexible
Caster Wheels.................................................................................................................................... 13 X 6.00 Flat Free
Spindles...................................... Heavy-duty 1-1/8" Top Dimension Spindle Shaft, Cast Housing, Taper Roller Bearing,
Low Maintenance with Top Access Grease Fitting and Grease Overfill Relief Poppet
Spindle Pulleys............................................................................................ Split Steel with Easily Removed Taper Hubs
Cutter Deck Belts .............................................................B-section with Kevlar Cord. Self-Adjusting, Self-Tightening
61V..................................................................................................................................Scag Part Number - 481558
72V.................................................................................................................................. Scag Part Number - 481980
Electric Clutch Type.........................................................................................................................Ogura Electric Clutch
Drive Shaft............................................................................................ClampYoke Shaft With Two High Speed U-Joints
HYDRAULIC SYSTEM3.5
Hydraulic Oil Filter......................................................................................................... 10 Micron Spin-on Element Type
Hydraulic Reservoir.....................................................................................................................Nylon; 3 Quart Capacity
WEIGHTS AND DIMENSIONS SMT61V SMT72V3.6
Length...............................................................................................................................87.5"................................87.5"
Tracking Width................................................................................................................... 55" ....................................55"
Overall Width w/chute down .............................................................................................73.5"...................................83"
Overall Width w/chute up...................................................................................................62" ....................................73"
Overall Height w/ROPS up...............................................................................................67.5"................................67.5"
Overall Height w/ROPS down...........................................................................................56.5"................................56.5"
Operating Weight...........................................................................................1540# (Kubota), 1700# (Cat)...........1750#
PRODUCTIVITY SMT61V SMT72V3.7
Cutting Width..................................................................................................................... 61" ....................................72"
Acres Per Day................................................................................................................... 23.7.....................................28
The preceding chart will aid you in determining how many acres your Scag mower will cut per day.The chart is an
estimate based on 8 hours per day cutting time at 6 MPH with an allowance for overlap and turns.

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Section 4
CAUTION
Do not attempt to operate this mower unless you
have read this manual. Learn the location and
purpose of all controls and instruments before
you operate this mower.
CONTROLS AND INSTRUMENT4.1
IDENTIFICATION
Before operating the mower, familiarize yourself with all
mowerand engine controls.Knowingthelocation,function
and operation of these controls is important for safe and
efficient operation of the mower.
Ignition Switch (Figure 4-1).1. The ignition switch
is used to start the engine.The ignition switch for
the STT-28CAT-SS has four positions; PREHEAT,
OFF, ON, and START.The ignition switch for the
STT61V-25KBD-SS has three positions; OFF, ON /
PREHEAT, and START
OPERATING INSTRUCTIONS
Mower Deck Switch (Figure 4-1).2. Used to engage
and disengage the mower drive system. Pulling up
on the switch will engage the deck drive. Pushing
down on the switch will disengage the deck drive.
Glow Plug Indicator (Figure 4-1).
3. Yellow indicator
turns on when the key switch is turned to the
PREHEAT position. Glow plugs must be preheated
for 5 to 10 seconds before starting the engine.
EngineThrottle Control (Figure 4-1).4. Used to
control the engine speed. Pushing the lever forward
increases engine speed. Pulling the lever back
decreases engine speed. Full back position is the
IDLE position. Full forward is the cutting position.
Voltmeter (Figure 4-1).5. Indicates the condition of
the charging system.When the engine is running, in
normal operating conditions, the needle should be in
the 12 to 14 volt range.
Oil Pressure (Figure 4-1).6. Indicates engine oil
pressure.Reference the engine operator's manual
for further information.
H
aljalefjairj f;o3rf
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aljalefjairj f;o3rf
OFF
OFF
OFF
C
LEFT STEERING
CONTROL
HOURMETER
FUEL GAUGE
DUMPVALVE
FUSES
ENGINE
THROTTLE
CONTROL
RIGHT STEERING
CONTROL
DECK LIFT
DECK RELEASE
PARKING BRAKE
CONTROL CUTTING HEIGHT
ADJUSTMENT
SEAT BELT
483762 GLOW
PLUGS
OFF ON
START
PREHEAT
MOWER DECK
PULL OUT TO ENGAGE
PUSH IN TO DISENGAGE
WATERTEMPERATURE
MOWER DECK SWITCH
OIL PRESSURE
IGNITION SWITCH
VOLTMETER
GLOW PLUG INDICATOR
Controls and InstrumentsFigure 4-1.

13
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Section 4
Hour meter (Figure 4-1).7. Indicates the number of
hours the engine has been operated.It operates
whenever the engine is running. Has preset
maintenance reminders for engine and hydraulic
system oil changes.Will start flashing scheduled
maintenance 2 hours before preset time and
continue flashing until 2 hours after. Automatically
resets.
Fuse Holders (Figure 4-1).
8. There are one 20-amp
fuse and one 50-amp resettable fuse that protect the
mower’s electrical system.To replace fuse, pull fuse
out of the socket and install a new fuse.
Left Steering Control (Figure 4-1).
9. Used to control
the mower's left wheel when traveling forward or
reverse.
Right Steering Control (Figure 4-1).10. Used to
control the mower's right wheel when traveling
forward or reverse.
Parking Brake Control (Figure 4-1).11. Used to
engage and disengage the parking brakes. Pull the
lever back to engage the parking brakes. Push the
lever forward to disengage the parking brakes.
FuelTank Gauge (Figure 4-1)12. . Indicates the
amount of fuel in the fuel tank.
DumpValve Control Levers (Figure 4-2).13. Located
on the hydraulic pumps, used to “free-wheel” the
mower. Rotating the levers clockwise until they stop
allows the unit to move under hydraulic power.The
levers must be in this position and torqued to 10ft/lbs
during operation of the mower.Rotating the levers
counter-clockwise allows the mower to be moved by
hand (free-wheeling).
DUMP VALVE
CONTROL
2007 STTDVC
DumpValve ControlFigure 4-2.
Deck Lift Foot Lever (Figure 4-1).14. Used to raise
and lower the cutter deck.
Cutting Height Adjustment (Figure 4-1).15. Used to
set the cutter deck at the desired cutting height.
Deck Release Lever (Figure 4-1).
16. Used to lock
the cutter deck in the transport position. Push the
foot pedal forward and lift up on the release lever to
release the cutter deck for normal mowing.
Temperature Gauge (Figure 4-1).17. Indicates the
operating temperature of the engine.
Seat Belt (Figure 4-1).
18. Used to secure the operator.
Seat belt must be worn at all times when the ROPS
is in the upright and locked position.
SAFETY INTERLOCK SYSTEM4.2
The mower is equipped with a safety interlock system
that prevents the engine from starting unless the deck
drive is disengaged, the parking brake is engaged, the
steering control levers are in the neutral position and the
operator is in the seat.The interlock system shuts off the
engine if the operator leaves the seat with the steering
control levers not in the neutral position and/or the cutter
blades engaged and the parking brake not engaged.
WARNING
Never operate the mower with the interlock
system disconnected or malfunctioning. Do not
disengage orbypassanyswitch;injurytoyourself
and others or property damage could result.
INITIAL RUN-IN PROCEDURES (FIRST4.3
DAY OF USE OR APPROXIMATELY 10
HOURS)
Check all belts for proper alignment and wear at 2, 41. and 8 hours.
Change the engine oil and oil filter after the first 202. hours of operation.(See Section 7.4.)
Check hydraulic oil level in reservoir. (See Section
3. 7.3.)
Check for loose hardware.Tighten as needed.4.
Check interlock system for proper operation.(See5. Section 4.2.)
Check tire pressure. Adjust pressure if6. necessary. (See Section 7.10)

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Section 4
STARTINGTHE ENGINE4.4
CAUTION
DO NOT USE STARTING FLUIDS. Use of starting
fluids in the air intake system may be potentially
explosive or cause a“runaway”engine condition
that could result in engine damage and/or
personal injury.
Be sure the fuel shutoff valve, located behind the1. operator's seat, is completely open.(See Section 7.5
Page 35)
Secure the ROPS in the upright and locked position.2.
Sit in the operator’s seat, fasten seat belt and place3. the steering control levers in the neutral position.
Engage the parking brake.
4.
Place the PTO switch in the disengaged position.5.
Move the engine throttle control to about half engine6. speed.
Turn the ignition key to the PREHEAT position for the7. STT-28CAT-SS or the ON position for the STT61V-
25KBD-SS for approximately 5 to 10 seconds to
allow the glow plugs to preheat before starting the
engine.Then turn the ignition key to the START
position and release the key as soon as the engine
starts.Do not hold the key in the START position for
more than 15 seconds at a time.Allow at least 60
seconds between each cranking attempt to prevent
overheating of the starter motor. Prolonged cranking
can damage the starter motor and shorten battery
life.
Allow engine to warm before operating the mower.8.
GROUNDTRAVEL AND STEERING4.5
- IMPORTANT -
If you are not familiar with the operation of a
machine with lever steering and/or hydrostatic
transmissions, the steering and ground speed
operations should be learned and practiced in
an open area, away from buildings, fences, or
obstructions. Practice until you are comfortable
withthehandlingofthemachinebeforeattempting
to mow. Learn the operation on flat ground before
operating on slopes.
- IMPORTANT -
Start practicingwithaslowenginespeedandslow
forward travel.
Learn to feather the steering controls to obtain a
smooth operating action.
Practice operating the mower until you are
comfortable with the controls before proceeding
to mow.
FORWARDTRAVEL
To travel forward with the mower, disengage the parking
brake and slowly push the steering control levers forward
an equal distance.The further the steering control levers
are pushed forward, the greater the forward speed will be.
To increase the speed, push the steering control levers
furtherforwardandtodecreasethespeed,pullthesteering
control levers back.
To stop the forward travel, pull the steering control levers
back to the neutral position.
To steer the mower left while traveling forward, pull the left
steering lever back.The further the lever is pulled back,the
quicker the mower will turn left.
To steer the mower right while traveling forward, pull the
right steering control lever back. The further the lever is
pulled back, the quicker the mower will turn right.
- NOTE -
Smooth operation of the steering levers will
produce smooth mower operation.While learning
the operation of the steering controls, keep the
travel speed low.
- IMPORTANT -
Do not travel forward over a curb.The mower will
hang up on the curb. Raise the deck and travel
backwardsoverthecurbata45degreeangle.(see
Section 4.13 on Page 18 for cutter deck raising
instructions)

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Section 4
REVERSETRAVEL
CAUTION
Disengage power to the mower before backing
up. Do not mow in reverse unless absolutely
necessary and then only after observation of the
entire area behind the mower.
CAUTION
Before backing up, observe the rear for persons
and obstructions. Clear the area before backing
up. Possible injury or property damage could
occur.
To travel in reverse,pull both handles back.Keepthe travel
speed low while traveling in reverse.
- NOTE -
The mower may not travel straight in reverse.
Slight adjustments may need to be made using
the steering controls.
To steer leftwhiletravelingin reverse,allowthe left steering
control lever to move forward. The further the control is
allowed to move forward, the quicker the mower will turn
left.
To steer right while traveling in reverse, allow the right
steering control lever to move forward. The further the
control is allowed to move forward, the quicker the mower
will turn right.
To stop the reverse travel, allow the steering control levers
toreturntotheneutralposition.Ifthemoweristobeparked,
engage the parking brake.
ENGAGINGTHE DECK DRIVE (CUTTER4.6
BLADES)
Set the throttle at about 3/4 speed. Do not attempt to1. engage the deck drive at high speed as this shortens
the electric clutch life — use only moderate engine
speed when engaging the deck drive.
Engage the deck drive by pulling out on the yellow
2. switch, located on the instrument panel, (Figure 4-3)
to the engage position.
390S0138
PULL UP TO ENGAGE
PUSH DOWN TO DISENGAGE
Cutter Engage SwitchFigure 4-3.
- NOTE -
A squealing noise may be heard when engaging
or disengaging the deck drive.It is caused by the
electricclutchplatesmeshingasthemowercomes
up to speed.
To disengage the deck drive, push the switch in to3. the disengage position.
Always operate the engine at full throttle to properly4. maintain cutting speed. If the engine starts to lug
down, reduce the forward speed and allow the
engine to operate at maximum RPM.

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Section 4
HILLSIDE OPERATION4.7
WARNING
DONOToperate on steepslopes.To checkaslope,
attempt to back up it (with the cutter deck down).
If the machine can back up the slope without the
wheels slipping, reduce speed and use extreme
caution. Under no circumstances should the
machine be operated on slopes greater than 15
degrees. ALWAYS FOLLOW OSHA APPROVED
OPERATION.
This mower has been designed for good traction1. and stability under normal mowing conditions.
However, caution must be used when traveling on
slopes, especially when the grass is wet.Wet grass
reduces traction and steering control.The Roll-Over
Protection System is standard equipment for this
machine.See Section 2.5, page 6 of this manual for
further details.
To prevent tipping or loss of control, do not start or2. stop suddenly, avoid unnecessary turns and travel
at reduced speed. If tires lose traction, disengage
blades and proceed slowly off the slope.
Avoid sudden starts when mowing uphill.Sudden3. starts may cause the machine to tip backwards.
Loss of traction may occur when traveling down hill.
4. Weight transfers to the front of the machine and
may cause the drive wheels to slip causing loss of
braking or steering.
Keep tires properly inflated.
5.
PARKINGTHE MOWER4.8
Park the machine on a flat, level surface only. Do not1. park the machine on an incline.
Place the steering control levers in the neutral
2. position.
Disengage the cutter blades.3.
Slow the engine to idle speed.4.
Engage the parking brake.5.
Turn the ignition key to the OFF position and remove6. the key.
AFTER OPERATION4.9
Wash the entire mower after each use.Do not1. use high pressure spray or direct the spray onto
electrical components.
- IMPORTANT -
Do not wash a hot or running engine. Cold water
will damage the engine. Use compressed air to
clean the engine if it is hot.
Keep the entire mower clean to inhibit serious heat
2. damage to the engine or hydraulic oil circuit.
Check the drive belts for proper alignment and any3. signs of wear. Correct and adjust if necessary.
DANGER
To avoid injury from burns, allow the mower
to cool before removing the fuel tank cap and
refueling.
After the mower has cooled down, fill the fuel tank
4. with fresh, clean fuel with a minimum cetane rating
of 40 at the end of every day of operation.
Check the tire pressure. Adjust pressure if5. necessary.
REMOVING CLOGGED MATERIAL4.10
DANGER
ROTATING BLADES
NEVERPUTYOURHANDSINTOTHEDISCHARGE
CHUTE FOR ANY REASON!
Shut off the engine and remove the key and
only then use a stick or similar object to remove
material if clogging has occurred.
If the discharge chute becomes clogged, shut off
1. the engine and remove the ignition key. Using a stick
or similar item, dislodge the clogged material.Then
resume normal mowing.