Scag Power Equipment STC User manual

MODEL STC
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 03079

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.
This manual covers the operating instructions
and illustrated parts list for:
STC40-17KA with a erial number of 5810000 to 5819999
STC48-19KA with a erial number of 5870000 to 5879999
STC48A-19KA with a erial number of 5880000 to 5889999
STC48-20CV with a erial number of 5980000 to 5989999
STC48A-20CV with a erial number of 6020000 to 6029999
STC48-21KA with a erial number of 5820000 to 5829999
STC48A-21KA with a erial number of 5890000 to 5899999
STC52A-21KA with a erial number of 5900000 to 5909999
STC52A-23KA with a erial number of 5910000 to 5919999
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 Drive Train Components ................................................................1
Section 2 - Safety Information
2.1 Introduction .............................................................................................................................2
2.2 Signal Words ...........................................................................................................................2
2.3 efore Operation Considerations ...........................................................................................2
2.4 Operation Considerations ........................................................................................................3
2.5 Maintenance Considerations ...................................................................................................4
2.6 Safety and Instructional Decals ..............................................................................................5
Section 3 - Specifications ....................................................................................................... 6-7
Section - Operating Instructions
4.1 Controls and Instrument Identification ....................................................................................8
4.2 Safety Interlock System ..........................................................................................................9
4.3 Initial Run-In Procedures ........................................................................................................9
4.4 Starting the Engine ................................................................................................................ 10
4.5 Ground Travel and Steering ..................................................................................................10
4.6 Engaging the Deck Drive ..................................................................................................... 11
4.7 Hillside Operation .................................................................................................................12
4-8 Parking the Mower ...............................................................................................................12
4.9 After Operation ....................................................................................................................12
4.10 Removing Clogged Material .................................................................................................13
4.11 Moving Mower with Engine Stopped ...................................................................................13
4.12 Recommendations for Mowing ............................................................................................. 13
4.13 Adjusting Cutting Height .......................................................................................................14
Section 5 - Troubleshooting Cutting Conditions .............................................................. 15-17

II
TABLE OF CONTENTS (CONT'D)
SUBJECT PAGE
Section 6 - Adjustments
6.1 Parking rake Adjustment ................................................................................................... 18
6.2 Travel Adjustments .............................................................................................................. 18
6.3 Throttle Control and Choke Adjustments ............................................................................. 20
6.4 elt Adjustment ................................................................................................................... 20
6.5 elt Alignment ..................................................................................................................... 20
6.6 Cutter Deck Adjustments ..................................................................................................... 21
Section 7 - Maintenance
7.1 Maintenance Chart ............................................................................................................... 23
7.2 Lubrication Fitting Points .................................................................................................... 24
7.3 Hydraulic System ................................................................................................................. 26
7.4 Engine Oil ............................................................................................................................ 27
7.5 Engine Fuel System .............................................................................................................. 27
7.6 Engine Air Cleaner ................................................................................................................ 28
7.7 attery .................................................................................................................................. 29
7.8 Drive elts ............................................................................................................................30
7.9 Cutter lades ........................................................................................................................ 30
7.10 Tires ...................................................................................................................................... 31
7.11 ody, Deck, and Upholstery ................................................................................................. 32
Section 8 - Replacement Parts
40" Cutter Deck ........................................................................................................................ 34-35
48:, 48A, 52A Cutter Deck ....................................................................................................... 36-37
Cutter Deck Controls ................................................................................................................ 38-39
Sheet Metal Components .......................................................................................................... 40-41
Drive System Components ....................................................................................................... 42-43
Engine and Attaching Parts ...................................................................................................... 44-45
Steering Components ................................................................................................................ 46-47
rake Components ................................................................................................................... 48-49
Fuel and Hydraulic System ....................................................................................................... 50-51
Electrical System ...................................................................................................................... 52-53
Hydraulic Pump Assembly ....................................................................................................... 54-55
Replacement Decals ................................................................................................................. 56-57
Electrical Schematic (Kawasaki & Kohler) ................................................................................... 58

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
Model
Serial
SCAG
Power Equipment
STC 2K SPL
SERIAL NUMBER
PLATE LOCATION

2
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 mower decals 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 mower safety decals
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 irreparable 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.
WARNING:
Section 2

3
11. Keep flammable objects (cigarettes, matches, etc.),
open flames and sparks away from the fuel tank and
fuel container.
12. quipment must comply with the latest requirements
per SA J137 and/or ANSI/ASA S279 when driven
on public roads.
-NOTE-
If the mower is driven on public roads, it must comply
with state and local ordinances as well as SAE J137
and/or A SI / ASAE S279 requirements. Contact
your local authorities for regulations and
equipment requirements.
13. DO NOT operate without the side discharge chute
installed and in the down position.
14. Check the blade mounting bolts at frequent intervals
for proper tightness.
15. 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 operateon steepslopes. Tocheck aslope,
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.
2.3 BEFORE OPERATION
CONSIDERATIONS (CONT'D)
5. 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.
6. 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.
7. 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
driveengaged and/orthe steeringcontrollevers not
in the neutral position and the parking brake not
engaged. Neveroperateequipmentwiththeinterlock
system disconnected or malfunctioning.
8. Be sure the interlock switches are functioning correctly.
9. 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.
10. DO NOT add fuel to a running or hot engine. Allow
the engine to cool for several minutes before adding
fuel.
Section 2
WARNING:
WARNING:

4
Section 2
2.4 OPERATION CONSIDERATIONS
(CONT'D)
3. To prevent tipping or loss of control, start and stop
smoothly, 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 u e your
hand to di lodge the clogged di charge 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.
6. 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.
7. Hydraulic fluid under high pressure may have sufficient
force to penetrate skin and cause serious injury. If
hydraulic fluid is injected into the skin, it must be
surgically removed within a few hours by a doctor or
gangrene may result.

5
Section 2
2.6 SAFETY AND INSTRUCTIONAL DECALS
DANGER
SPINNING BLADE
KEEP CLEAR
CONTACT CAN INJURE
48071
ROTATING BLADES AND BELTS
WARNING
KEEP HANDS, FEET & CLOTHING CLEAR
KEEP ALL GUARDS IN PLACE
SHUT OFF ENGINE & DISENGAGE BLADE
CLUTCH BEFORE SERVICING
CLEAR AREA OF DEBRIS BEFORE MOWING
USE CAUTION IN DIRECTING DISCHARGE
KEEP BYSTANDERS, CHILDREN & PETS AWAY
READ INSTRUCTION MANUAL BEFORE OPERATING
DO NOT OPERATE WITHOUT DISCHARGE CHUTE, MULCHING
KIT, OR ENTIRE GRASS CATCHER INSTALLED
481040
CAUTION
KEEP BYSTANDERS AWAY
CAUTION
BEFORE OPERATING
READ OPERATINGS
MANUAL AND SAFETY
INSTRUCTIONS
481567
START / DRIVE
PROCEDURE
ENGAGE PARKING BRAKE
DISENGAGE MOWER DECK DRIVE
MOVE CONTROL HANDLES
TO NEUTRAL LOCK POSITION
START ENGINE
RELEASE PARKING BRAKE
SELECT FORWARD OR
REVERSE SPEED WITH
HYDRO CONTROL HANDLES
WARNING
INSTALL BELT COVER BEFORE
OPERATING MACHINE
READ OPERATOR'S MANUAL
481039
481568
FORWARD
REVERSE
FR
CAUTION
AVOID INJURY FROM
BURNS. SHUT OFF
ENGINE BEFORE
REMOVING FUEL
TANK CAP.
481272

6
Section 3
SPECIFICATIONS
3.1 ENGINE
General Type .............................................................................. Heavy Duty Industrial/Commercial Gasoline
Brand ......................................................................................... Kawasaki, Kohler
Horsepower ................................................................................ 7 HP (Spec.#FH500V) (Scag Model STC40- 7KA)
9 HP (Spec.#FH60 V) (Scag Model STC48- 9KA, STC48A- 9KA)
20 HP (Spec.#CV20S) (Scag Model STC48-20CV, STC48A-20CV)
2 HP (Spec.#FH64 V) (Scag Model STC48-2 KA, STC48A-2 KA,
STC52A-2 KA)
23 HP (Spec.#FH680V) (Scag Model STC52A-23KA)
Type ........................................................................................... 4 Cycle Gasoline, Twin Cylinder, Horizontal Shaft
Cylinders .................................................................................... 2 with Cast Iron Sleeves
Governor .................................................................................... Mechanical Type with Variable Speed Control Set At 3600 RPM
Idle Speed .................................................................................. 550 RPM - Kawasaki
900 RPM - Kohler
Kawasaki Fuel Pump Group ....................................................... Mechanical Fuel Pump with In-Line Fuel Filter, Fixed Jet Downdraft
Carburetor.
Fuel ............................................................................................ Non-Leaded Gasoline with a Minimum Octane Rating of 87
Oil Pump Group .......................................................................... Positive Displacement Gerotor Oil Pump
Starter ......................................................................................... Electric Starting with Solenoid Shift Starter
Belts: .......................................................................................... Kevlar cord. Self-adjusting, Self-tightening
Pump Drive Belt ...................................................................... Scag Part Number - 482009
3.2 ELECTRICAL
Battery ....................................................................................... 2 Volt
Charging System ........................................................................ Alternator
Charging Output ........................................................................ 2 Volt, 3 Amp - Kawasaki
2 Volt, 5 Amp - Kohler
System Polarity .......................................................................... Negative Ground
Starter ......................................................................................... 2 Volt Electric Ring Gear Type, Key and Solenoid Operated
Interlock Switches ...................................................................... Seat, Neutral Control, Mower Engagement (BBC), Parking Brake
Instrument Panel ........................................................................ Hourmeter, Key Switch, Throttle Lever, Manual Choke,
PTO Switch, Fuses and Safety Start module
Fuses ......................................................................................... Two (2) 20 Amp
3.3TRACTOR
Drive System .............................................................................. Hydraulic Drive with Two Variable Displacement Pumps and Two
Cast-iron High Torque Motors
Hydrostatic Pumps .................................................................... Two Hydro-Gear BDP 0L Pumps with Dump Valves for
movement without running the engine
Drive Wheel Motors .................................................................. Two Ross Cast-iron High Torque Motors
Steering/Travel Control .............................................................. Twin Lever Fingertip Steering Control with Individual Control to
Each Wheel with Gas Spring Dampers
Parking Brake ............................................................................. Lever Actuated Linkage to Brakes on Both Drive Wheel Axles
Wheels:
(2) Front Caster ...................................................................... 3 X 5-6 Four-Ply w/tapered roller bearing pivots
(2) Drive - (40" Deck) ............................................................. 23 X 8.5 X 2 Four-Ply Pneumatic Tubeless, Radius Edge
(2) Drive - (48"-52" Deck) ...................................................... 24 X 2 X 2 Four-Ply Pneumatic Tubeless, Radius Edge
Fuel Tanks .................................................................................. 2 @ 4.5-Gallon Seamless Polyethylene Tank with large opening and
Fuel Gauge Fill Cap
Tire Pressure:
Front Caster ........................................................................... 25 PSI
Drive ...................................................................................... 8 PSI
Seat ............................................................................................ Padded, Thick Cushion with Extra Spring Support