Scag Power Equipment STR Operator's User manual

FROM SERIAL NUMBER 60001 TO 69999
OPERATOR'S MANUAL
PART 03028
TURF RUNNER
MODEL STR

FAILURE TO FOLLOW SAFE OPERATING PRACTICES
MAY RESULT IN SERIOUS INJURY.
* Keepallshieldsinplace,especially thegrassdischargechute.
* Beforeperforminganymaintenanceorservice, stop themachineand
remove the spark plug wire and ignition key.
* Ifa mechanism becomes clogged,stopthe engine before cleaning.
* Keephands, feet andclothing away frompower-drivenparts.
* Readthis manualcompletelyas wellasother manualsthatcame
withyour mower.
* Keepothers off the tractor(onlyone person at atime).
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
Thismanualcoverstheoperatinginstructions
and illustrated partslist for:
STR-20CH with a serial number of 21660001-21669999
STR-22CH with a serial number of 21760001-21769999
Alwaysuse theentireserial numberlistedon theserialnumber
tagwhen referringto thisproduct.

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 Before 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 4 - Operating Instructions
4.1 Controls and Instrument Identification................................................................................... 8
4.2 Safety Interlock System ....................................................................................................... 10
4.3 Initial Run-In Procedures ..................................................................................................... 10
4.4 Starting the Engine............................................................................................................... 10
4.5 Ground Travel and Steering................................................................................................. 10
4.6 Engaging the Deck Drive ..................................................................................................... 12
4.7 Hillside Operation ................................................................................................................ 13
4-8 Parking the Mower............................................................................................................... 13
4.9 After Operation .................................................................................................................... 13
4.10 Hopper/Side Discharge Operation ....................................................................................... 14
4.11 Removing Clogged Material ................................................................................................ 15
4.12 Moving Mower with Engine Stopped .................................................................................. 16
4.13 Recommendationsfor Mowing ............................................................................................ 16
4.14 Adjusting Cutting Height ..................................................................................................... 17
4.15 Tilting the Cutter Deck......................................................................................................... 17
4.16 Removing the Cutter Deck ................................................................................................... 17
Section 5 - Troubleshooting Cutting Conditions.............................................................20-22

II
TABLE OF CONTENTS (CONT'D)
SUBJECT PAGE
Section 6 - Adjustments
6.1 Parking Brake Adjustment ................................................................................................... 23
6.2 Travel Adjustments .............................................................................................................. 24
6.3 Throttle Control and Choke Adjustments............................................................................. 28
6.4 EngineBelt Adjustment .......................................................................................................28
6.5 Blower Drive Belt Adjustment ............................................................................................. 28
6.6 Transmission Drive Belt Adjustment ................................................................................... 28
6.7 Belt Alignment ..................................................................................................................... 28
Section 7 - Maintenance
7.1 Maintenance Chart ............................................................................................................... 29
7.2 Lubrication........................................................................................................................... 30
7.3 Hydraulic System ................................................................................................................. 32
7.4 EngineOil ............................................................................................................................ 33
7.5 Engine Fuel System..........................................................................................................34
7.6 Engine Air Cleaner............................................................................................................... 34
7.7 Battery ................................................................................................................................. 35
7.8 Drive Belts ........................................................................................................................... 36
7.9 Cutter Blades ....................................................................................................................... 37
7.10 Tires ..................................................................................................................................... 38
7.11 Hopper ................................................................................................................................. 39
7.12 Transmission Gearbox ......................................................................................................... 39
7.13 Cutter Deck Gearboxes ........................................................................................................ 39
7.14 Body, Deck, Hopper and Upholstery.................................................................................... 41
Section 8 - Replacement Parts
Cutter Deck.................................................................................................................................... 42
Sheet Metal .................................................................................................................................... 44
Blower Assembly ........................................................................................................................... 46
Engine and Attaching Parts ........................................................................................................... 48
Traction Drive................................................................................................................................ 50
Hydraulic Pump ............................................................................................................................. 52
Hydro-Gear Axle Assembly........................................................................................................... 54
Drive Gearbox ............................................................................................................................... 56
DeckDrive ..................................................................................................................................... 58
Speed and Steering Controls .......................................................................................................... 60
Parking Brake and Dump Valve Linkages ..................................................................................... 62
Hydraulic Components and Lines ..................................................................................................64
Electrical System ........................................................................................................................... 66
Hopper ........................................................................................................................................... 68
Hopper Actuator Mechanism......................................................................................................... 70
Decals ............................................................................................................................................ 72
Electrical Schematic ...................................................................................................................... 74

Section 1
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 and cutting deck. The serial plates
are located where shown in Figures 1-1 and 1-2.
For pictorial clarity, some illustrations and figures in this
manualmayshowshields,guardsorplates open or removed.
Under no circumstances should your mower be operated
without these devices in place.
Allinformationis based uponproductinformationavailable
at 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
arereferencedfrom the operator’s rightandleftwhen seated
in the normal operating position and facing the
forward travel direction.
1.3 SERVICINGTHE 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. Forserviceofthesecomponentsduringthelimited
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.
Figure 1-1 Mower Deck Serial Plate Location Figure 1-2 Tractor Serial Plate Location
Serial Plate
Serial Plate

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.
Hazardcontrol and accidentprevention are dependentupon
the awareness, concern, prudence, and proper training of
the personnel involved in the operation, transport,
maintenanceandstorageofthe equipment. Make sure every
operator is properly trained and thoroughly familiar with
all of the controls before operating the mower.
READ THIS OPERATOR’S MANUAL BEFORE
ATTEMPTING TO START YOUR MOWER.
A replacement manual is available from your authorized
Scag Service Dealer or by Contacting Scag Power
Equipment,Service Department atP.O.Box152, Mayville,
WI 53050. There is a nominal charge of $2.00 for each
manual. Please indicate the complete model and serial
number of your Scag product.
2.2 SIGNAL WORDS
This symbol means “Attention! Become Alert! Your
SafetyisInvolved!" Thesymbol is usedwiththe following
signal words to attract your attention to safety messages
found on the decals and throughout this manual. The
message that follows the symbol contains important
informationaboutsafety. Toavoidinjury and possible death,
carefully read the message! Be sure to fully understand
the causes of possible injury or death.
SignalWord:
It is a distinctive word on safety decals and throughout this
manual that alerts the viewer to the existence and relative
degree of the hazard.
The signal word “WARNING” denotes 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
hazardoussituation exists onor near themachine 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
practicesonor near themachinethatcouldresult 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. DONOTmowwhenchildren 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 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.
WARNING:
Section 2

3
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. Keepall shieldsand safety devicesin place.
If a shield, safety device or decal is defective or
damaged, repair or replace it before operating the
machine.
13. DO NOT operate without a chute deflector installed;
keep the deflector in lowest possible position.
14. Check the blade mounting bolts at frequent intervals
for proper tightness.
15. Make sure all hydraulic fluid connections are tight and
allhydraulichosesandlinesareingoodconditionbefore
starting the machine.
WARNING:
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
operator is seated in the seat, the deck drive is
disengaged, and the speed control is placed in
the neutral position. The system also shuts off
the engine if the operator leaves the seat with
the mower running and the speed control is not
in the neutral postion. It will also shut off the
engine if the hopper is raised with the cutter deck
drive engaged. Never operate equipment with
the interlock system disconnected or
malfunctioning.
8. Be sure interlock switches are functioning correctly.
9. Fuel is flammable; handle with care. Fill fuel tank
outdoors. Never fill indoors. Use a funnel or spout to
inhibit spillage. Clean up any spillage before starting
theengine.
10. DO NOT add fuel to a running or hot engine. An
explosioncould occur. Allow engine tocoolforseveral
minutes before adding fuel.
11. Keepflammableobjects(cigarettes, matches, etc.), open
flames and sparks away from fthe uel tank and fuel
container.
12. Equipment must comply with the latest requirements
per ANSI J137 and/or ANSI S279 when driven on
public roads.
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.
WARNING:
DO NOT operate on steep slopes. To check a
slope, attempt to drive up it (with cutter deck
down). If machine can drive up the slope without
the wheels slipping, reduce speed and use
extreme caution. ALWAYS FOLLOW OSHA
APPROVED OPERATION.
3. Do not stop or start suddenly. WHEN GOING UP
HILL OR DOWN HILL, MOW UP AND DOWN
THEFACEOF SLOPES, NEVERACROSS THE
FACE.
4. When usingany attachment,never direct thedischarge
of material toward bystanders or allow anyone near
the machine while in operation.
5. Before attemptingto startthe engine, disengagepower
to the cutter deck 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.
Section 2

4
7. Be alert for holes, rocks, and roots in the terrain and
other hidden hazards. 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 mower 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. Watchfor traffic when crossingroads or operatingnear
roadways.
11. Mow only in daylight or good artificial light.
12. Take allpossibleprecautions when leaving themachine
unattended, such as disengaging the mower, lowering
theattachments, settingtheparking brake,stopping the
engine, and removing the key.
13. Disengage power tothe attachments whentransporting
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
engineis running orimmediately after stopping. These
areas may be hot enough to cause a burn.
16. DONOT run engine insidea building orconfined area
without proper ventilation. Exhaust fumes are
hazardaous and could cause death.
2.5 MAINTENANCE CONSIDERATIONS
1. Nevermake adjustments to themachinewiththe 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. Donotchangetheenginegovernorsettingsoroverspeed
theengine.
5. To reduce fire hazard, keep the engine free of grass,
leaves, excessive grease and dirt.
6. Hydraulic fluid is under high pressure. Keep body
and hands away from pinholes or nozzles that eject
hydraulicfluidunderhighpressure. Use only cardboard
or paper to search for leaks.
7. Hydraulicfluid under high pressuremayhavesufficient
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.
Section 2

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
BEFORE OPERATING
READ OPERATORS
MANUAL AND SAFETY
INSTRUCTIONS
KEEP BYSTANDERS AWAY
CAUTION
WARNING
INSTALL BELT COVER BEFORE
OPERATING MACHINE
READ OPERATOR'S MANUAL
481039

6
SPECIFICATIONS
3.1 ENGINE
General Type ............................................................................. Heavy Duty Industrial/Commercial Gasoline
Brand ......................................................................................... Kohler
Model ......................................................................................... Command
Horsepower ................................................................................ 20 HP at 3600 RPM (Scag Model STR48-20CH)
22 HP at 3600 RPM (Scag Model STR48-22CH)
Type ........................................................................................... 4 Cycle Gasoline, Twin Cylinder, Horizontal Shaft
Displacement ............................................................................. 624 cc.
Cylinders ................................................................................... 2 with Cast Iron Sleeves
Governor.................................................................................... Mechanical Type with Variable Speed Control Set At 3600 RPM
Idle Speed ..................................................................................1400 RPM
Fuel Pump Group ......................................................................Mechanical Fuel Pump with In-Line Fuel Filter, Fixed Jet
Carburetor with Smart-Choke™ and Fuel Shutdown Solenoid
Fuel ............................................................................................ Non-Leaded Gasoline with a Minimum Octane Rating of 97
Oil Pump Group: .......................................................................Positive Displacement Gerotor™ Oil Pump with Remote Oil
Filter
Starter ........................................................................................ Electric Starting with Cell Starter
Belts:
Engine Belt............................................................................ Scag Part Number - 481235
Blower Drive Belt ................................................................ Scag Part Number - 481234
Left Pump Drive Belt ........................................................... Scag Part Number - 481236
Right Hand Drive Belt .......................................................... Scag Part Number - 481237
3.2 ELECTRICAL
Battery ....................................................................................... 12 Volt
Charging System ....................................................................... Alternator
Charging Output ....................................................................... 12 Volt, 30 Amp
System Polarity.......................................................................... Negative Ground
Starter ........................................................................................ 12 Volt Electric Ring Gear Type, Key and Solenoid Operated
Interlock Switches ..................................................................... Seat, Neutral Control, Mower Engagement (BBC), and Hopper
Instrument Panel ....................................................................... Ammeter, Hourmeter, Key Switch, Throttle Lever, Manual Choke,
BBC Switch, and Fuses
Fuses .......................................................................................... Two (2) 30 Amp
3.3 TRACTOR
Drive System ............................................................................. Hydraulic Drive with Two Hydrostatic Transmissions For
Independent Control of Each Drive Wheel
Hydrostatic Transmissions ........................................................ Two Hydro-Gear™ Transmissions with Integral Pump/Motor
with Axle
Steering/Travel Control............................................................. Twin Lever Fingertip Steering Control with Individual Control to
Each Wheel
Parking Brake............................................................................ Lever Actuated Linkage to Brakes on Both Drive Wheel Axles
Wheels:
(2) Front Caster.................................................................... 9 x 3.5 Smooth Tires
(2) Drive ............................................................................... 20 x 10.8 Four-Ply Pneumatic Tubeless, Radius Edge
(1) Rear ................................................................................
Fuel Tank ................................................................................... 5-Gallon Seamless Polyethylene Tank with Fuel Gauge Fill Cap
Tire Pressure:
Front Caster.......................................................................... 25 PSI
Drive..................................................................................... 15 PSI
Rear ...................................................................................... 15 PSI
Seat ............................................................................................ Padded
Section 3