Scag Power Equipment STT User manual

MODEL STT
OPERATOR’S MANUAL
THIS MANUAL CONTAINS 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 THAT THIS
BOOK COVERS ARE CONTAINED ON THE
INSIDE COVER. BEFORE OPERATING YOUR
MACHINE, PLEASE READ ALL THE INFOR-
MATION ENCLOSED.
PART NUMBER 03092

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 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:
Always use the entire serial number listed on the serial number
tag when referring to this product.
This manual covers the operating instructions
and illustrated parts list for:
STT52A-23CH with a s rial numb r of 6670001 to 6679999
STT61A-23CH with a s rial numb r of 6680001 to 6689999
STT52A-23KA with a s rial numb r of 7200001 to 7209999
STT61A-23KA with a s rial numb r of 7210001 to 7219999
STT52A-25CH with a s rial numb r of 6700001 to 6709999
STT61A-25CH with a s rial numb r of 6710001 to 6719999
STT52A-22KA with a s rial numb r of 6740001 to 6749999
STT61A-22KA with a s rial numb r of 6750001 to 6759999
STT61A-27KA with a s rial numb r of 6760001 to 6769999
STT 72A-27KA with a s rial numb r of 7140001 to 7149999

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 Drive Train Components ................................................................1
1.3 Sym ols ............................................................................................................................... 2-3
Section 2 - Safety Information
2.1 Introduction .............................................................................................................................4
2.2 Signal Words ...........................................................................................................................4
2.3 Considerations Before Operation ...........................................................................................4
2.4 Operation Considerations ........................................................................................................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 ...................................................................................................... 11
4.4 Starting the Engine ................................................................................................................ 12
4.5 Ground Travel and Steering ..................................................................................................12
4.6 Engaging the Deck Drive .....................................................................................................13
4.7 Hillside Operation .................................................................................................................14
4-8 Parking the Mower ...............................................................................................................14
4.9 After Operation .................................................................................................................... 14
4.10 Removing Clogged Material .................................................................................................15
4.11 Moving Mower with Engine Stopped ...................................................................................15
4.12 Recommendations for Mowing ............................................................................................. 15
4.13 Adjusting Cutting Height .......................................................................................................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 Travel Adjustments ............................................................................................................... 20
6.3 Throttle Control and Choke Adjustments .............................................................................. 22
6.4 Belt Adjustment .................................................................................................................... 22
6.5 Belt Alignment ...................................................................................................................... 22
6.6 Cutter Deck Adjustments .....................................................................................................23
Section 7 - Maintenance
7.1 Maintenance Chart ............................................................................................................... 25
7.2 Lu rication Fitting Points ...................................................................................................... 26
7.3 Hydraulic System .................................................................................................................. 27
7.4 Engine Oil ............................................................................................................................. 29
7.5 Engine Fuel System .............................................................................................................. 30
7.6 Engine Air Cleaner ................................................................................................................ 30
7.7 Battery .................................................................................................................................. 31
7.8 Drive Belts ............................................................................................................................ 32
7.9 Cutter Blades ........................................................................................................................ 32
7.10 Tires ...................................................................................................................................... 33
7.11 Cutter Deck Gear ox ........................................................................................................... 34
7.12 Kawasaki Cooling System .................................................................................................... 34
7.13 Body, Deck, Hopper and Upholstery ....................................................................................35
Section 8 - Replacement Parts
STT52A, STT61A Cutter Deck ............................................................................................... 36-37
STT72A Cutter Deck ............................................................................................................... 38-39
Cutter Deck Controls ................................................................................................................ 40-41
Sheet Metal Components .......................................................................................................... 42-43
Deck Drive Components .......................................................................................................... 44-45
Engine and Attaching Parts (Kohler) ........................................................................................ 46-47
Engine and Attaching Parts (22HP Kawasaki) ........................................................................ 48-49
Engine and Attaching Parts (23HP & 27HP Kawasaki) .......................................................... 50-51
Brake and Steering Components .............................................................................................. 52-53
Fuel and Hydraulic System for Kohler & Kawasaki w/52" & 61" Cutter Decks .................... 54-55
Fuel and Hydraulic System for 27HP Kawasaki w/72" Cutter Deck ...................................... 56-57
Electrical System (Kohler) ....................................................................................................... 58-59
Electrical System (22HP Kawasaki) ........................................................................................ 60-61
Electrical System (23HP & 27HP Kawasaki) .......................................................................... 62-63
Hydraulic Pump ........................................................................................................................ 64-65
Replacement Decals ................................................................................................................. 66-67
Electrical Schematic (Kohler) ........................................................................................................ 68
Electrical Schematic (22HP Kawasaki) ......................................................................................... 69
Electrical Schematic (23HP & 27HP Kawasaki ............................................................................ 70

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 quipment 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 i ba ed upon product information
available at the time of approval for printing. Scag
Power Equipment re erve the right to make
change 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 1-1 Tractor 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
C Mark
Transmission
Choke
On/Start Spring Tension on Idler
Oil
Off/Stop
SYMBOL DESCRIPTION
SYMBOL DESCRIPTION
ISO Symbol
Spinning Blade
48071S
Parking Brake
WARNING
FALLING HAZARD
USE ONLY SCAG APPROVED
RIDING ATTACHMENTS
SEE OPERATOR'S MANUAL
481109
Falling Hazard

3
Slow
Fast
Cutting lement - ngage
Cutting lement - Basic symbol
Cutting lement - Disengage
Continuously Variable - Linear
Read Operator's Oanual
Keep Bystanders Away
Pinch Point
481039S
SYMBOL DESCRIPTION SYMBOL DESCRIPTION
Hourmeter/ lapsed 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
quipment, Service Department at P.O. Box 152,
Mayville, WI 53050. 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 i 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 DANG R 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 nglish
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. quipment must comply with the latest requirements
per SA J137 and/or ANSI/ASA 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 A SI / 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.
DONOT 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.
This machine is equipped with an interlock
system intended to protect the operator and
others from injury. This is accomplished by
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:
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 drive engaged and/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.
-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. Mow only in 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. xhaust
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 i under high pre ure. 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)

7
Section 2
2.6 SAFETY AND INSTRUCTIONAL DECALS
WARNING
INSTALL BELT COVER BEFORE
OPERATING MACHINE
READ OPERATOR'S MANUAL
481039
390S0150A
481568
FORWARD
REVERSE
FR
IMPORTANT ADJUSTMENT
PROCEDURES
READ OPERATOR'S MANUAL
FOR MORE DETAILS
NEUTRAL ADJUSTMENT
TRACKING ADJUSTMENT
FREE WHEEL OPERATION
HYDRAULIC TANK FLUID LEVEL
Check tire pressure-
(Drive tires - 12 psi,
Caster tires - 25 psi)
To move machine without running
the engine, rotate both dump valve
levers located at the LH side of
the pumps CCW 1/2 turn to
"freewheel" positions. Return
levers to original position to
operate the mower.
If the machine pulls to the right,
adjust LH control linkage CCW to
slow left wheel. If the machine
pulls to the left, adjust RH control
linkage CCW to slow right wheel.
Readjust neutral if necessary.
With an operator in the seat,
engine running, control levers
in neutral and the parking brake
disengaged - adjust control
linkage. Loosen jam nuts. If wheel
rotates forward, adjust turnbuckle
CCW. If wheel rotates rearward,
adjust turnbuckle CW. Adjust until
drive wheel stops turning. Tighten
jam nuts. Repeat for opposite side.
Check hydraulic fluid level
daily while fluid is cool.
Fluid level should be 3-1/4"
below top of filler neck.
Fill with SAE 20W50 motor oil only.
IMPORTANT!:
Do not overfill. Room for hot
fluid expansion must be allowed
or resulting expansion may cause
leaks in the system.
Gearbox lubricant:
SAE 80W90 gear oil
481588
Loosen jam nuts
Rotate turnbuckle

8
SPECIFICATIONS
Section 3
3.1 ENGINE
General Type .............................................................................. Heavy Duty Industrial/Commercial Gasoline
Brand ......................................................................................... Kohler, 23H (Spec. # S-76523) 25H (Spec. # S-68645)
Kawasaki, 22H (Spec. # FD661D-AS0201)
Kawasaki, 23H (Spec. #FD671D-AS01)
Kawasaki, 27H (Spec. #FD750D-AS04)
Model ......................................................................................... Kohler Command, Kaw. FD661D, Kaw. FD671D, Kaw. FD750D
Horsepower ................................................................................ 23 H at 3600 R M (Model STT52&52A-23CH, STT61&61A-23CH)
25 H at 3600 R M (Model STT52&52A-25CH, STT61&61A-25CH)
22 H at 3600 R M (Model STT52A-22KA, STT61A-22KA)
23 H at 3600 R M (Model STT52A-23KA, STT61A-23KA)
27 H at 3600 R M (Model STT61A-27KA, STT72A-27KA)
Type ........................................................................................... 4 Cycle Gasoline, Twin Cylinder, Horizontal Shaft
Displacement ............................................................................ 23H Kohler 674 cc., 25H Kohler 725cc.
.................................................................................................. 22H Kaw. 617cc., 23H Kaw. 671cc., 27H Kaw. 745cc.
Cylinders .................................................................................... 2 with Cast Iron Sleeves
Governor .................................................................................... Mechanical Type with Variable Speed Control Set At 3600 R M
Idle Speed .................................................................................. 1400 R M
Kohler Fuel ump Group ............................................................ Mechanical Type Fuel ump with In-Line Fuel Filter, Fixed Jet
Carburetor with Smart-Choke and Fuel Shutdown Solenoid
Kawasaki Fuel ump Group ....................................................... Electric Fuel ump with In-Line Fuel Filter,Fixed Jet Downdraft
Carburetor.
Fuel ............................................................................................ Non-Leaded Gasoline with a Minimum Octane Rating of 87
Oil ump Group .......................................................................... ositive Displacement Gerotor Oil ump with Remote Oil
Filter
Starter ......................................................................................... Electric Starting with Solenoid Shift Starter
Belts: .......................................................................................... Kevlar cord. Self-adjusting, Self-tightening
Deck Drive Belt ....................................................................... Scag art Number - 481460
ump Drive Belt ...................................................................... Scag art Number - 482171
Kawasaki Fan Belt .................................................................. art Number - Mitsubishi 59011-2056 (Avail. Through Kawasaki)
3.2 ELECTRICAL
Battery ....................................................................................... 12 Volt
Charging System ........................................................................ Alternator
Charging Output ........................................................................ 12 Volt, 15 Amp
System olarity .......................................................................... Negative Ground
Starter ......................................................................................... 12 Volt Electric Ring Gear Type, Key and Solenoid Operated
Interlock Switches ...................................................................... Seat, Neutral Control, Mower Engagement (BBC), arking Brake
Instrument anel ........................................................................ Ammeter, Hourmeter, Key Switch, Throttle Lever, Manual Choke,
BBC Switch, Fuses and Safety Start module, Temp. gauge (KA)
Fuses ......................................................................................... Two (2) 20 Amp
3.3TRACTOR
Drive System .............................................................................. Hydraulic Drive with Two Variable Displacement umps and Two
Cast-iron High Torque Motors
Hydrostatic umps .................................................................... Two Hydro-Gear BD 10L umps with Dump Valves for
movement without running the engine
Drive Wheel Motors .................................................................. Two Ross Model MB 15 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
arking Brake ............................................................................. Lever Actuated Linkage to Brakes on Both Drive Wheel Axles
Wheels:
(2) Front Caster ...................................................................... 13 X 5.00 Four- ly
(2) Drive ................................................................................. 23 X 10.5 X 12 Four- ly neumatic Tubeless, Radius Edge, 52"
................................................................................................... 24X12.0X12 Four- ly neumatic Tubeless, Radius Edge, 61"
Fuel Tank ................................................................................... 10-Gallon Seamless olyethylene Tank with Fuel Gauge Fill Cap
Tire ressure:
Front Caster ........................................................................... 25 SI
Drive ...................................................................................... 12 SI
Seat ............................................................................................ added, Thick Cushion with tall back rest

9
3.3 TRACTOR (CONT'D)
Travel Speed:
Forward ................................................................................. 0-10 M H
Reverse .................................................................................. 0-5 M H
3.4 CUTTER DECK
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 late.
7-gauge (3/16") deck skirt.
True Cutting Width: ................................................................... 52" (132.0 cm), 61" (155.0 cm)
Cutting Height Adjustment: ....................................................... Foot Operated Lever Adjustment from Operator's Seat, 1.00" to
6.00" in 1/2"increments
Cutter Blades: ............................................................................. .197 Thick, Milled Edge, Wear Resistant Marbain
SMT 52A: Three (3) 18" blades
SMT 61A: Three (3) 21" blades
Blade Engagement: ................................................................... Electric Blade Engagement Clutch with Control anel 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, olypropylene ( lastic), Flexible
Caster Wheels: ........................................................................... 13x 5.00 Four- ly
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 oppet
Spindle ulleys: .......................................................................... Cast-iron with Easily Removed Taper Hubs
Cutter Deck Belts: ...................................................................... B-section with Kevlar Cord. Self-adjusting, Self-tightening
SMT52 ................................................................................... Scag art Number - 482281
SMT61 ................................................................................... Scag art Number - 481558
Electric Clutch Type ................................................................... Ogura Electric Clutch
Drive Shaft ................................................................................. Quick-disconnect Shaft With Two High Speed U-Joints
3.6 HYDRAULIC SYSTEM
Hydraulic Oil Filter ..................................................................... 10 Micron Spin-on Element Type
Hydraulic Reservoir ................................................................... Nylon; 6 Quart Capacity
3.7 WEIGHTS AND DIMENSIONS SMT52A SMT61A SMT72A
Length 78" 81.75" 79.0"
Tracking Width 51" 51" 56.0"
Overall Width 62" 72" 83.5"
Overall Height 30" 30" 46.0"
Operating Weight 1160# 1200# 1310#
Section 3
3.8 PRODUCTIVITY
The following 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 4 M H with an allowance for overlap and turns.
Cutting Width: 36" 48" 52" 61" 72"
Acres Per Day: 9.5 12.5 13.5 16 19
-NOTE-
The machine will travel at 10mph for
transport purposes. For best cutting
performance the forward travel speed
should be adjusted depending upon the
cutting conditions.

10
Section 4
OPERATING INSTRUCTIONS
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.
4.1 CONTROLS AND INSTRUMENT
IDENTIFICATION
Before operating the mower, familiarize yourself with all
mower and engine controls. Knowing the location,
function and operation of these controls is important for
safe and efficient operation of the mower.
CAUTION:
1. Ignition Switch (Figure 4-1). The ignition switch is
used to start the engine and has three positions; OFF,
ON, and ST RT.
2. Mower Deck Switch (Figure 4-1). 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.
3. Engine Choke Control (Figure 4-1). Used to
start a cold engine.
4. Engine Throttle Control (Figure 4-1). 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.
Figure 4-1 Controls and Instruments
CHOKE
481348
aljalefjairjf;o3rf
af krjf ;wso rgf
aljal efj airjf;o3rf
aljalefjairjf;o3rf
OFF
OFF
OFF
AMMETER
LEFT STEERING
CONTROL
MOWER DECK SWITCH
IGNITION SWITCH
HOURMETER FUEL GAUGE
DUMPVALVEDUMPVALVE
FUSES
ENGINE
CHOKE
CONTROL
ENGINETHROTTLE
CONTROL
RIGHT STEERING
CONTROL
DECK LIFT
DECK RELEASE
390S0142A
PARKING BRAKE
CONTROL
CUTTING HEIGHT
ADJUSTMENT
PULL OUT TO ENGAGE
ON
START
PUSH INTO DISENGAGE
OFF
481669
MOWER DECK
AMMETER
MOWER DECK SWITCH
IGNITION SWITCH
HOURMETER
TEMPERATURE GAUGE
KAWASAKI MACHINE ONLY

11
Section 4
5. mmeter (Figure 4-1). Indicates the condition of
the charging system. When the engine is running the
needle should be toward the positive end of the meter.
If the needle is toward the negative end of the meter,
this indicates a discharge condition and the machine
should be taken in for service.
6. Hourmeter (Figure 4-1). Indicates the number of
hours the engine has been operated. It operates
whenever the ignition key switch is in the ON
position. It can be used to keep track of maintenance
intervals and the amount of time required to perform
various tasks.
7. Fuse Holders (Figure 4-1). Two 20-amp fuses
protect the mowers electrical system. To replace
fuses, pull fuse out of the socket and install a new
fuse.
8. Left Steering Control (Figure 4-1). Used to control
the mower's left wheel when traveling forward or
reverse.
9. Right Steering Control (Figure 4-1). Used to
control the mower's right wheel when traveling
forward or reverse.
10. Parking Brake Control (Figure 4-1). 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.
11. Fuel Tank Gauge (Figure 4-1). Indicates the
amount of fuel in the fuel tank.
12. Dump Valve Control Levers (Figure 4-2). 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 during operation of the
mower. Rotating the levers counter-clockwise allows
the mower to be moved by hand (free-wheeling).
13. Deck Lift Foot Lever (Figure 4-1). Used to raise
and lower the cutter deck.
14. Cutting Height djustment (Figure 4-1). Used
to set the cutter deck at the desired cutting height.
Figure 4-2 Dump Valve Control
4.2 SAFETY INTERLOCK SYSTEM
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.
Never operate the mower with the interlock
system disconnected or malfunctioning. Do not
disengage or bypass any switch; injury to
yourself and others or property damage could
result.
4.3 INITIAL RUN-IN PROCEDURES (First
Day of Use or Approximately 10 Hours)
1. Check all belts for proper alignment and wear at 2, 4
and 8 hours.
WARNING:
390S0141
DUMP VALVE
CONTROL LEVER
15. Deck Release Lever (Figure 4-1). 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.
16. Temperature Gauge (Figure 4-1). Indicates the
operating temperature of the engine. Used on
mowers with the Kawasaki liquid cooled engine
only.

12
Section 4
2. Change the engine oil and oil filter after the first 5
hours of operation. (See Section 7.4.)
3. Check hydraulic oil level in reservoir. (See Section
7.3.)
4. Check for loose hardware. Tighten as needed.
5. Check interlock system for proper operation. (See
Section 4.2.)
6. Check tire pressure. djust pressure if necessary.
(See Section 7.10.)
4.5 GROUND TRAVEL AND STEERING
4.4 STARTING THE ENGINE
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.
1. Be sure the fuel shutoff valve, located behind the
operator's seat, is completely open. (See section 7.5.)
2. Sit in the operators seat and place the steering
control levers in the neutral position.
3. Engage the parking brake.
4. If the engine is cold, choke the engine as needed.
5. Move the engine throttle control to about half engine
speed.
6. Turn the ignition key to the ST RT position and
release the key as soon as the engine starts. Do not
hold the key in the ST RT position for more than 15
seconds at a time. llow 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.
7. llow engine to warm before operating the mower.
CAUTION:
-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
with the handling of the machine before
attempting to mow. earn the operation on flat
ground before operating on slopes.
-IMPORTANT-
Start practicing with a slow engine speed and
slow forward travel.
earn 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.
Forward Travel
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
further forward and to decrease the speed, pull the
steering 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.

13
Section 4
-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 backwards over the curb at a
45 degree angle. (see section 4.13 for cutter
deck raising instructions)
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.
To travel in reverse, pull both handles back. Keep the
travel speed low while traveling in reverse.
-NOTE-
The mower will not travel straight in reverse.
Slight adjustments must be made using the
steering controls.
To steer left while traveling in reverse, allow the 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 to return to the neutral position. If the mower is to
be parked, engage the parking brake.
4.6 ENGAGING THE DECK DRIVE (CUTTER
BLADES)
1. Set the throttle at about 3/4 speed. Do not attempt to
engage the deck drive at high speed as this shortens
the electric clutch life  use only moderate engine
speed when engaging the deck drive.
2. Engage the deck drive by pulling out on the yellow
switch, located on the instrument panel, (Figure 4-3)
to the engage position.
-NOTE-
A squealing noise may be heard when engaging
or disengaging the deck drive. It is caused by
the electric clutch plates meshing as the mower
comes up to speed.
3. To disengage the deck drive, push the switch in to the
disengage position.
4. lways operate the engine at full throttle to properly
maintain cutting speed. If the engine starts to lug
down, reduce the forward speed and allow the
engine to operate at maximum RPM.
CAUTION:
Reverse Travel
Before backing up, observe behind the mower for
persons and obstructions. Clear the area before
backing up. Possible injury or property damage
couldoccur.
CAUTION:
Figure 4-3 Cutter Engage Switch
STT99CES
PULL UP TO ENGAGE
PUSH DOWN TO DISENGAGE

14
Section 4
4.7 HILLSIDE OPERATION
DONOT operate on steep slopes. To checka 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.
1. The mower has been designed for good traction 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.
2. To prevent tipping or loss of control, do not start or
stop suddenly, avoid unnecessary turns and travel at
reduced speed.
3. Keep tires properly inflated.
4.8 PARKING THE MOWER
1. Place the steering control levers in the neutral
position.
2. 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 remove
the key.
4.9 AFTER OPERATION
1. Wash the entire mower after each use. Do not use
high pressure spray or direct the spray onto electrical
components.
WARNING:
-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.
2. Keep the entire mower clean to inhibit serious heat
damage to the engine or hydraulic oil circuit.
3. Check the drive belts for proper alignment and any
signs of wear. Correct and adjust if necessary.
4. fter the mower has cooled down, fill the fuel tank
with fresh, clean fuel at the end of every day of
operation.
5. Check the tire pressure. djust pressure if
necessary.
To avoid injury from burns, allow the mower to
cool before removing the fuel tank cap and refuel-
ing.

15
Section 4
4.10 REMOVING CLOGGED MATERIAL
ROTATING BLADES
NEVER PUT YOUR HANDS INTO THE DISCHARGE
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.
1. If the discharge chute becomes clogged, shut off the
engine and remove the ignition key. Using a stick or
similar item, dislodge the clogged material. Then
resume normal mowing.
4.11 MOVING MOWER WITH ENGINE
STOPPED
To free-wheel or move the mower around without the
engine running, place the dump valve levers in the FREE-
WHEEL position (Figure 4-2). Disengage the parking
brake and move the mower by hand. The dump valve
levers must be returned to the DRIVE position to drive
the mower.
4.12 RECOMMENDATIONS FOR MOWING
1. Do not mow with dull blades. dull blade will tear
grass, resulting in poor lawn appearance and require
extra power.
2. The discharge chute must not be removed and must
be kept in the lowest position to deflect grass
clippings and thrown objects downward. Direct the
side discharge away from sidewalks or streets to
minimize cleanup of clippings. When mowing close
to obstacles, direct the discharge away from the
obstacles to reduce the chance of property damage by
thrown objects.
3. Cut grass when it is dry and not too tall. Do not cut
grass too short (cut off 1/3 or less of existing grass
for best appearance). Mow frequently.
4. Keep mower and discharge chute clean.
5. When mowing wet or tall grass, mow the grass
twice. Raise the mower to the highest setting for the
first pass and then make a second pass to the desired
height.
6. Use a slow travel speed for trimming purposes.
7. Operate the engine at full throttle for best cutting.
Mowing with a lower RPM causes the mower to tear
the grass. The engine is designed to be operated at
full speed.
8. Use the alternate stripe pattern for best lawn
appearance. Vary the direction of the stripe each
time the grass is mowed to avoid wear patterns in the
grass.

16
Section 4
4.13 ADJUSTING CUTTING HEIGHT
The mower deck can be adjusted from a height of 1-inch
to 6 inches at 1/2-inch intervals. To adjust the cutting
height:
Do not adjust the cutting height with the mower
blades rotating. Disengage the power to the cutter
blades and then adjust cutting height.
1. Disengage the power to the cutter blades.
2. Push the cutting height adjustment foot pedal all the
way forward using your right foot until it locks in
place. (Figure 4-6).
3. Insert the lanyard pin into the cutting height index at
the desired cutting height. Push forward on the deck
lift foot lever, hold in place and lift up on the deck
release lever, (Figure 4-7). Slowly release the foot
pedal. deck height decal is located on the cutting
height index as an aid in adjusting the deck to the
desired height. (Figure 4-6).
Figure 4-7 Deck Release Lever
WARNING:
390S0140
LANYARD PIN
HEIGHT ADJUSTMENT PEDAL
CUTTING
HEIGHT
6
5.5
5
4.5
4
3.5
3
2.5
2
1.5
1
481543
Figure 4-6 Adjusting Cutting Height
390S0151
DECK
RELEASE
LEVER