Scag Power Equipment STT User manual

MODEL STT
OPERATOR’S MANUAL
THIS MANUALCONTAINS THE OPERATING
INSTRUCTIONS AND SAFETY INFORMA-
TION FOR YOUR SCAG MOWER. READING
THIS MANUAL CAN PROVIDE YOU WITH
ASSISTANCE IN MAINTENANCE AND AD-
JUSTMENT PROCEDURES TO KEEP YOUR
MOWER PERFORMING TO MAXIMUM EFFI-
CIENCY. THE SPECIFIC MODELS THATTHIS
BOOK COVERS ARE CONTAINED ON THE
INSIDECOVER. BEFORE OPERATINGYOUR
MACHINE, PLEASE READ ALL THE INFOR-
MATION ENCLOSED.
PART NUMBER 03120

FAILURE TO FOLLOW SAFE OPERATING PRACTICES
MAY RESULT IN SERIOUS INJURY.
* Keepall shields inplace, especially thegrass 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.
* Read this manual completely as well as other manuals that came
with your mower.
* Keep others off the tractor (only one person at a time)
REMEMBER - YOUR MOWER IS ONLY AS SAFE AS THE 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 of the equipment.
WARNING:
Alwaysusetheentireserial number listed on the serialnumber
tag when referring to this product.
Thismanualcoverstheoperatinginstructions
andillustratedparts list for:
STT52A-23KA with a serial number of 8480001 to 8489999
STT52A-25CH with a serial number of 8490001 to 8499999
STT52A-27CH with a serial number of 8720001 to 8729999
STT61A-23KA with a serial number of 8500001 to 8509999
STT61A-25CH with a serial number of 8510001 to 8519999
STT61A-27KA with a serial number of 8520001 to 8529999
STT61A-27CH with a serial number of 8730001 to 8739999
STT61A-29KA-DFI with a serial number of 8530001 to 8539999
STT72A-27KA with a serial number of 8540001 to 8549999
STT72A-29KA-DFI with a serial number of 8550001 to 8559999
SMT-52A with a serial number of 8560001 to 8569999
SMT-61A with a serial number of 8570001 to 8579999
SMST-72A with a serial number of 8610001 to 8619999

I
TABLE OF CONTENTS
SUBJECT PAGE
Section 1 - General Information
1.1 Introduction .............................................................................................................................1
1.2 Directional Reference.............................................................................................................1
1.3 Servicing the Engine and DriveTrain Components ................................................................1
1.3 Symbols ............................................................................................................................... 2-3
Section 2 - Safety Information
2.1 Introduction .............................................................................................................................4
2.2 SignalWords ...........................................................................................................................4
2.3 Considerations Before Operation ...........................................................................................4
2.4 OperationConsiderations........................................................................................................5
2.5 Maintenance Considerations ...................................................................................................6
2.6 Safety and Instructional Decals ..............................................................................................7
Section 3 - Specifications.......................................................................................................8-9
Section 4 - Operating Instructions
4.1 Controls and Instrument Identification ..................................................................................10
4.2 Safety Interlock System........................................................................................................ 11
4.3 Initial Run-In Procedures ......................................................................................................12
4.4 Starting the Engine................................................................................................................12
4.5 Ground Travel and Steering ..................................................................................................12
4.6 Engaging the Deck Drive .....................................................................................................13
4.7 HillsideOperation .................................................................................................................14
4-8 Parking the Mower ...............................................................................................................14
4.9 After Operation ....................................................................................................................14
4.10 Removing Clogged Material .................................................................................................14
4.11 Moving Mower with Engine Stopped ...................................................................................14
4.12 Recommendations for Mowing .............................................................................................15
4.13 Adjusting Cutting Height .......................................................................................................15
4.14 Towing ..................................................................................................................................16
Section 5 -Troubleshooting Cutting Conditions.............................................................17-19

II
TABLE OF CONTENTS (CONT'D)
SUBJECT PAGE
Section 6 - Adjustments
6.1 Parking Brake Adjustment ....................................................................................................20
6.2 TravelAdjustments ...............................................................................................................20
6.3 Throttle Control and ChokeAdjustments ..............................................................................22
6.4 BeltAdjustment ....................................................................................................................22
6.5 BeltAlignment ......................................................................................................................22
6.6 Cutter Deck Adjustments .....................................................................................................23
Section 7 - Maintenance
7.1 Maintenance Chart ...............................................................................................................26
7.2 LubricationFittingPoints ......................................................................................................27
7.3 Hydraulic System ..................................................................................................................29
7.4 EngineOil .............................................................................................................................30
7.5 Engine Fuel System ..............................................................................................................31
7.6 EngineAir Cleaner................................................................................................................31
7.7 Battery ..................................................................................................................................32
7.8 Drive Belts ............................................................................................................................33
7.9 Cutter Blades ........................................................................................................................33
7.10 Tires ......................................................................................................................................34
7.11 Cutter Deck Gearbox ...........................................................................................................35
7.12 Kawasaki Cooling System ....................................................................................................35
7.13 Body, Deck, Hopper and Upholstery ....................................................................................36
Section 8 - Replacement Parts
Notes ..............................................................................................................................................37
STT52A, STT61A Cutter Deck ............................................................................................... 38-39
STT72A Cutter Deck ............................................................................................................... 40-41
Cutter Deck Controls................................................................................................................ 42-43
Sheet Metal Components.......................................................................................................... 44-45
Deck Drive Components .......................................................................................................... 46-47
Engine and Attaching Parts (Kohler)........................................................................................ 48-49
Engine and Attaching Parts (Kawasaki) .................................................................................. 50-51
Brake and Steering Components .............................................................................................. 52-53
Fuel and Hydraulic System ....................................................................................................... 54-55
Fuel and Hydraulic System (Kawasaki 29DFI) ....................................................................... 56-57
Hydraulic Pump (BDP-16A) .................................................................................................... 58-59
Electrical System (Kohler) ....................................................................................................... 60-61
Electrical System (Kawasaki 23HP & 27HP) ......................................................................... 62-63
Electrical System (Kawasaki 29DFI)....................................................................................... 64-65
Replacement Decals................................................................................................................. 66-67
Electrical Schematic (Kohler) ........................................................................................................68
Electrical Schematic (Kawasaki 23HP & 27) ................................................................................69
Electrical Schematic (Kawasaki 29DFI)........................................................................................70
Warranty Statement............................................................................................. Inside Back Cover

1
GENERAL INFORMATION
1.1 INTRODUCTION
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
Scag dealers are informed of the latest methods to
service 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.
USE OF OTHER THAN ORIGINAL SCAG
REPLACEMENT PARTS WILL VOID THE
WARRANTY.
When ordering parts, always give the model and serial
number of your tractor. The serial number plate is
located where shown in Figure 1-1.
For pictorial clarity, some illustrations and figures in this
manual may show shields, guards or plates open or
removed. Under no circumstances should your mower
be operated without these devices in place.
All information is based upon product information
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.
1.2 DIRECTION REFERENCE
The “Right” and “Left”, “Front” and “Rear” of the
machine are referenced from the operator’s right and left
when seated in the normal operating position and facing
the forward travel direction.
1.3 SERVICING THE ENGINE AND DRIVE
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
the component manufacturer. Any unauthorized work
done on these components during the warranty period
may void your warranty.
Section 1
Figure 1-1Tractor Serial Number Plate Location
390S0137A
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

2
CE Mark
Transmission
Choke
On/Start Spring Tension on Idler
Oil
Off/Stop
SYMBOL DESCRIPTION
SYMBOL DESCRIPTION
ISO Symbols
SpinningBlade
48071S
Parking Brake
WARNING
FALLING HAZARD 
USE ONLY SCAG APPROVED 
RIDING ATTACHMENTS
SEE OPERATOR'S MANUAL
481109
FallingHazard

3
Slow
Fast
Cutting Element - Engage
Cutting Element - Basic symbol
Cutting Element - Disengage
Continuously Variable - Linear
Read Operator's Manual
Keep Bystanders Away
Pinch Point
481039S
SYMBOL DESCRIPTION SYMBOL DESCRIPTION
Hourmeter/Elapsed Operating Hours
Thown Object Hazard

4
SAFETY INFORMATION
2.1 INTRODUCTION
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, maintenance and storage of the
equipment. Make sure every operator is properly trained
and thoroughly familiar with all of the controls before
operating the mower.
READ THIS OPERATOR’S MANUAL BEFORE
ATTEMPTING TO START YOUR MOWER.
A replacement manual is available from your authorized
Scag Service Dealer or by contacting Scag Power
Equipment, Service Department at P.O. Box 152,
Mayville, WI 53050 or contact us via the Internet at
www.scag.com. Use the contact form to make your
request. Please indicate the complete model and serial
number of your Scag product when requesting
replacement manuals.
2.2 SIGNAL WORDS
This symbol means “Attention! Become Alert! Your
Safety is Involved!" The symbol is used with the
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 possible death, carefully read the
message! Be sure to fully understand the causes of
possible injury or death.
Signal Word:
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.
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.
The signal word “DANGER” denotes that an extremely
hazardous situation exists on or near the machine that
could result in high probability of death or irrepairable
injury if proper precautions are not taken.
CAUTION:
The signal word “CAUTION” is a reminder of safety
practices 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.
2.3 BEFORE OPERATION
CONSIDERATIONS
1. NEVER allow children to operate this riding mower.
Do not allow adults to operate this machine without
proper instructions.
2. DO NOT mow when children and/or others are
present.
3. Clear the area to be mowed of objects that could be
picked up and thrown by the cutter blades.
4. DO NOT carry passengers.
5. DO NOT operate the machine under the influence
of alcohol or drugs.
6. If the operator(s) or mechanic(s) cannot read English
it is the owner's responsibility to explain this material
to them.
WARNING:
Section 2

5
12. DO NOT add fuel to a running or hot engine. Allow
the engine to cool for several minutes before adding
fuel.
13. Keep flammable objects (cigarettes, matches, etc.),
open flames and sparks away from the fuel tank and
fuel container.
14. Equipment must comply with the latest requirements
per SAE J137 and/or ANSI/ASAE S279 when
driven on public roads.
If the mower is driven on public roads, it must
comply with state and local ordinances as well as
SAE J137 and/or ANSI / ASAE S279
requirements. Contact your local authorities for
regulations and equipment requirements.
15. DO NOT operate without the side discharge chute
installed and in the down position.
16. Check the blade mounting bolts at frequent intervals
for proper tightness.
17. Make sure all hydraulic fluid connections are tight
and all hydraulic hoses and lines are in good condition
before starting the machine.
2.4 OPERATION CONSIDERATIONS
1. Know the function of all controls and how to stop
quickly.
2. Reduce speed and exercise extreme caution on
slopes and in sharp turns to prevent tipping or loss of
control. Be especially cautious when changing
directions on slopes.
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. ALWAYS FOLLOW OSHA APPROVED
OPERATION.
8. Operator hearing protection is recommended,
particularly for continuous operation of the mower.
Wear suitable hearing protection. Prolonged
exposure to loud noise can cause hearing
impairment or loss.
9. Keep the machine and attachments in good
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.
Thismachineisequipped with an interlock system
intended to protect the operator and others from
injury. This is accomplished by preventing the
2.3 BEFORE OPERATION
CONSIDERATIONS (CONT'D)
7. DO NOT wear loose fitting clothing that 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.
Section 2
WARNING:
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
engine if the operator leaves the seat with the deck
driveengagedand/orthesteering control levers are
not in the neutral postion and the parking brake is
not engaged. Never operate equipment with the
interlock system disconnected or malfunctioning.
10. Be sure the interlock switches are functioning
correctly.
11. Fuel is flammable; handle it with care. Fill the fuel
tank outdoors. Never fill it indoors. Use a funnel or
spout to prevent spillage. Clean up any spillage
before starting the engine.
-NOTE-
WARNING:

6
Section 2
3. To prevent tipping or loss of control, do not start or
stop suddenly. Always avoid unnecessary turns and
travel at reduced speed.
4. When using any attachment, never direct the
discharge of material toward bystanders or allow
anyone near the machine while in operation.
5. Before attempting to start the engine, with the
operator in the seat, disengage power to the cutter
deck, place the steering control levers in the neutral
position and engage the parking brake.
6. If the mower discharge ever plugs, shut off the
engine, remove the ignition key, and wait for all
movement to stop before removing the obstruction.
Do not use your hand to dislodge the clogged
discharge chute. Use a stick or other device to
remove clogged material.
7. Be alert for holes, rocks, roots and other hidden
hazards in the terrain. Keep away from any dropoff.
Beware of overhead obstructions (low limbs, etc.),
underground obstacles (sprinklers, pipes, tree roots,
etc.). Cautiously enter a new area. Be alert for
hidden hazards.
8. Disengage power to cutter deck before backing up.
Do not mow in reverse unless absolutely necessary
and then only after observation of the entire area
behind the mower.
9. DO NOT turn sharply. Use care when backing up.
10. Disengage power to cutter deck before crossing
roads, walks or gravel drives.
11. Mowonlyin daylight or good artificial light.
12. Take all possible precautions when leaving the
machine unattended, such as disengaging the mower,
lowering the attachments, setting the parking brake,
stopping the engine, and removing the key.
13. Disengage power to the attachments when
transporting or when not in use.
14. The machine and attachments should be stopped and
inspected for damage after striking a foreign object,
and damage should be repaired before restarting and
operating the machine.
15. 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.
16. DO NOT run the engine inside a building or a
confined area without proper ventilation. Exhaust
fumes are hazardous and could cause death.
2.5 MAINTENANCE CONSIDERATIONS
1. Never make adjustments to the machine with the
engine running unless specifically instructed to do so.
If the engine is running, keep hands, feet, and
clothing away from moving parts.
2. Remove the key from the ignition switch to prevent
accidental starting of the engine when servicing or
adjusting the machine.
3. Keep all nuts, bolts and screws tight, to ensure the
machine is in safe working condition. Check blade
mounting bolts frequently to be sure they are tight.
4. Do not change the engine governor settings or
overspeed the engine. See the engine operator's
manual for information on engine settings.
5. To reduce fire hazard, keep the engine free of grass,
leaves, excessive grease, oil and dirt.
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 surgically removed
within a few hours by a doctor or gangrene may
result.
WARNING:
2.4 OPERATION CONSIDERATIONS
(CONT'D)