Scag Power Equipment STT-31BSD User manual

MODEL STT-31BSD
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 NO. 03153
PRINTED10/04
PRINTED IN USA
©2004
SCAGPOWEREQUIPMENT
DIVISION OF METALCRAFT OF MAYVILLE, INC.

FAILURE TO FOLLOW SAFE OPERATING PRACTICES
MAY RESULT IN SERIOUS INJURY.
* Keep all shields in place, especially the grass discharge chute.
* Before performing any maintenance or service, stop the machine and
remove the spark plug wires and ignition key.
* Ifa mechanism becomes clogged,stop the engine beforecleaning.
* Keep hands, feet and clothing away from power-driven parts.
* Read this manual completely as well as other manuals that came
withyourmower.
* Keep others off the tractor (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 of the equipment.
This manual covers the operating instructions
and illustrated parts list for:
STT-31BSD with a serial number of A7400001 to A7499999
SMST-61A with a serial number of A7500001 to A7599999
SMST-72A with a serial number of A7600001 to A7699999
Always use the entire serial number listed on the serial number
tag when referring to this product.
WARNING:

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
Section 2 - Safety Information
Symbols ............................................................................................................................... 2-3
2.1 Introduction .............................................................................................................................4
2.2 SignalWords ...........................................................................................................................4
2.3 Before Operation Considerations ...........................................................................................4
2.4 Operation Considerations ........................................................................................................5
2.5 Roll Over Protection System ..................................................................................................6
2.6 Maintenance Considerations ...................................................................................................8
2.7 Safety and Instructional Decals ..............................................................................................9
Section 3 - Specifications ....................................................................................................10-11
Section 4 - Operating Instructions
4.1 Controls and Instrument Identification ..................................................................................12
4.2 Safety Interlock System........................................................................................................13
4.3 Initial Run-In Procedures......................................................................................................14
4.4 Starting the Engine ................................................................................................................14
4.5 Ground Travel and Steering ..................................................................................................14
4.6 Engaging the Deck Drive .....................................................................................................15
4.7 HillsideOperation .................................................................................................................16
4-8 Parking the Mower ...............................................................................................................16
4.9 After Operation ....................................................................................................................16
4.10 Removing Clogged Material .................................................................................................17
4.11 Moving Mower with Engine Stopped ...................................................................................17
4.12 Recommendations for Mowing .............................................................................................17
4.13 Adjusting Cutting Height .......................................................................................................18
Section 5 -Troubleshooting Cutting Conditions.............................................................. 19-21

II
TABLE OF CONTENTS (CONT'D)
SUBJECT PAGE
Section 6 - Adjustments
6.1 Parking Brake Adjustment ....................................................................................................22
6.2 TravelAdjustments ...............................................................................................................22
6.3 Throttle Control and ChokeAdjustments..............................................................................24
6.4 BeltAdjustment ....................................................................................................................24
6.5 BeltAlignment ......................................................................................................................24
6.6 Cutter Deck Adjustments .....................................................................................................25
Section 7 - Maintenance
7.1 Maintenance Chart ...............................................................................................................28
7.2 LubricationFitting Points ......................................................................................................29
7.3 Hydraulic System ..................................................................................................................31
7.4 EngineOil .............................................................................................................................32
7.5 Engine Fuel System ..............................................................................................................33
7.6 EngineAir Cleaner................................................................................................................33
7.7 Battery ..................................................................................................................................33
7.8 Drive Belts ............................................................................................................................35
7.9 Cutter Blades ........................................................................................................................35
7.10 Tires ......................................................................................................................................36
7.11 Cutter Deck Gearbox ...........................................................................................................36
7.12 CoolingSystem .....................................................................................................................37
7.13 Body, Deck, Hopper and Upholstery ....................................................................................38
Section 8 - Illustrated Parts List
Notes ..............................................................................................................................................39
SMST 61"Adv., 72"Adv. Cutter Decks ................................................................................... 40-41
Cutter Deck Controls................................................................................................................ 42-43
Sheet Metal Components.......................................................................................................... 44-45
STT Roll Over Protection......................................................................................................... 46-47
Deck Drive Components .......................................................................................................... 48-49
Radiator, Coolers & Engine Brackets.................................................................................50-51
Brake & Steering Components..........................................................................................52-53
Fuel & Hydraulic System ......................................................................................................... 54-55
Electrical System ...................................................................................................................... 56-57
Hydraulic Pump Assembly - BDP-21L .................................................................................... 58-59
Wire Harness, STT-31BSD ............................................................................................................60
Replacement Decals................................................................................................................. 61-62
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
DivisionofMetalcraftofMayville,Inc.
Mayville,Wisconsin53050
PatentsIssuedandPending
MANUFACTUREDUNDERONEORMORE
OF THEFOLLOWINGPATENTS:
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
WARNING:
USE ONLY SCAG APPROVED ATTACHMENTS
AND ACCESSORIES.
Attachments and accessories manufactured by companies
otherthanScagPowerEquipmentarenotapprovedforuse
on this machine.
Scag approved attachments and accessories:
GC-STT(p/n 9049, 9039)
GC-STT-CS (p/n 9053, 9041)
Mulch Plate (p/n 9261, 9262)
Hurricane Mulch (p/n 9266, 9267)
Cup Holder (p/n 9240)
STT Hitch (p/n 9242)
STT Bumper (p/n 9256)
STT - Suspension Seat (p/n 9270)
STT - Lights (p/n 9279)
Tiger Striper (p/n 9269)
Blade Buddy (p/n 9212)

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. The owner/user can prevent and is
responsible for accidents or injuries occuring to
themselves, other people or property.
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 via the Internet at
www.scag.com. The manual for your 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.
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. 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.
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.
WARNING:
Section 2

5
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.
This machine is equipped with an interlock system
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
engine if the operator leaves the seat with the deck
driveengagedand/or the steering 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.
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 or with an optional
grass catcher or mulch plate completely installed.
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
7. DO NOT wear loose fitting clothing. Loose
clothing, 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.
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.
2.3 BEFORE OPERATION
CONSIDERATIONS (CONT'D)
6. If the operator(s) or mechanic(s) cannot read English
or Spanish, it is the owner's responsibility to explain
this material to them.
Section 2
WARNING:
OPERATION.
-NOTE-
WARNING:

6
Section 2
2.4 OPERATION CONSIDERATIONS
(CONT'D)
3. To prevent tipping or loss of control, start and stop
smoothly, avoid unnecessary turns andtravelatreduced
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
ofoverheadobstructions(lowlimbs, etc.), underground
obstacles(sprinklers,pipes,treeroots,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
andthenonlyafterobservationoftheentireareabehind
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. NEVER raise the deck with the blades engaged.
13. Takeallpossibleprecautionswhenleavingthemachine
unattended, such as disengaging the mower, lowering
theattachments, setting the parking brake, stoppingthe
engine, and removing the key.
14. Disengagepower to theattachments when transporting
or when not in use.
15. 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.
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.
DO NOT run the engine inside a building or a
confined area without proper ventilation. Exhaust
fumes are hazardous and could cause death.
16. Keep hands and feet away from cutter blades and
moving parts. Contact can injure.
17. Use care when loading or unloading the machine onto
a trailer or truck.
18. Usecarewhenapproachingblindcorners,shrubs,trees,
or other objects that may obscure vision.
WARNING: WARNING:
CAUTION:
2.5 ROLL OVER PROTECTION SYSTEM
WARNING:
Seat belt must be securely fastened during
operation. Failure to do so could cause
serious injury or loss of life.