The Engine Owner’s Manual provides information regarding the U.S. Environmental Protection Agency (EPA)
and the California Emission Control Regulation of emission systems, maintenance and warranty.
Keep Engine Owner’s Manual with your unit. Should the Engine Owner’s Manual become damaged or
illegible, replace immediately. Replacements may be ordered per the information found in the Product
Information section of the owner’s manual.
Federal law and California State law prohibit the following acts or the causing thereof:
1. The removal or rendering inoperative by any person other than for purposes of maintenance,
repair, replacement, of any device or element of design incorporated into any equipment for the
purposes of emissions control prior to or after its sales or delivery to the ultimate purchaser or
while it is in use, or
2. The use of the equipment after such device or element of design has been remov ed or rendered
inoperative by any person.
WARNING
The engine exhaust from this product
contains chemicals known to the state
of California to cause cancer, birth
defects or other reproductive harm.
NOTICE OF REQUIREMENT OF SPARK ARRESTER MUFFLER
This equipment may create sparks that can start fires around dry vegetation. California Public Resources Code
Section 4442.6 provides that it is unlawful to use or operate an internal combustion engine on any forest-covered,
brush-covered, or grass-covered land unless the engine is equipped with a spark arrester maintained in effective
working order. A spark arrester is a device constructed of nonflammable materials specifically for the purpose of
removing and retaining carbon and other flammable particles over 0.0232 of an inch in size from the exhaust flow of
an internal combustion engine that uses hydrocarbon fuels or which is qualified and rated by the United States
Forest Service. Other states or federal areas may have similar laws. The Operator Should Contact Local Fire
Agencies For Laws or Regulations Relating to Fire Prevention Requ irement s. THIS EQUIPMENT DOES NOT HAVE
A SPARK ARRESTER AND YOU SHOULD CONTACT YOUR AUTHORIZED DEALER FOR THE PURCHASE OF
A SPARK ARRESTER.
Inspect spark arrester daily; replace every 500 hours or as needed.
This manual is part of a service package for the BigDog® R
Series mowers. Use of this manual in conjunction with other
BigDog
the information necessary to service and maintain BigDog
®
R Series mower and component manuals will provide
®
R
Series mowers.
This General Service Manual is a service guide for use by
Service Technicians. It provides the necessary information
needed to perform normal maintenance requirements on these
units.
The Parts Manual provides a complete parts listing for the
unit. Use this manual when ordering parts.
The Operator's Manual provides fundamental operational
information and operational safety that is needed when
operating the mower.
The component manuals are furnished by the various
manufacturers to be used for the troubleshooting and servicing
of their products.
Maintenance Introduction
Regular maintenance is the best prevention for costly
downtime or expensive, premature repair. The following pages
contain suggested maintenance information and schedules
which the operator/mechanic should follow on a routine basis.
Remain alert for unusual noises, they could be signaling a
problem. Visually inspect the machine for any abnormal wear or
damage. A good time to detect potential problems is while
performing scheduled maintenance service. Correcting the
problem as quickly as possible is the best insurance.
Clear away heavy build-up of grease, oil and dirt, especially
in the engine and under the seat platform areas; minute dust
particles are abrasive to close-tolerance engine and hydraulic
assemblies.
Daily inspect mower for grass clippings and wire and string
tangles. The underside of the mower deck will collect a build-up
of grass clippings and dirt, especially when grass is wet or has
high moisture content. This build-up will harden, restricting
blade and air movement and will probably show a poorer quality
of cutting. Therefore it should be removed routinely.
To do this it will be necessary to raise and block the deck,
using jack stands or blocks, in the full up position and scrape the
build-up from underneath.
Some repairs require the assistance of a trained service
mechanic and should not be attempted by unskilled personnel.
Consult your BigDog
®
Mowers service center when assistance
is needed.
Information included in this manual was current at the time of
printing, but subsequent production changes may cause your
machine to vary slightly in detail. BigDog
®
Mowers reserves the
right to redesign and change the machine as deemed necessary,
without notification. If a change has been made to your machine
which is not reflected in this service manual contact the
Customer Service Department at BigDog
®
Mowers for
additional information.
Warranty
Warranty repair must be performed by a BigDog® Mowers
Authorized Dealer before warranty credit can be allowed. Work
performed by anyone other than an Authorized Dealer will
invalidate the warranty claim and warranty credit will not be
approved.
108935BD1-1REV E
Page 6
REV E1-2108935BD
Page 7
SAFETY
DANGER
WARNING
This safety alert symbol is used to call attention to a message
intended to provide a reasonable degree of PERSONAL
SAFETY for operators and other persons during the normal
operation and servicing of this equipment.
– denotes immediate hazards which WILL result in
severe personal injury or death.
– denotes a hazard or unsafe practice which COULD
result in severe personal injury or death.
Safe Servicing Practices
This product is capable of amputating hands and feet and
throwing objects. Always follow all safety instructions to avoid
serious injury or death.
Understand Correct Service
Be sure you understand a service procedure before you
work on the machine.
Unauthorized modifications to the machine may impair
the function and/or safety and affect machine life.
If it is necessary to make checks with the engine running,
always use two people - with the operator at the controls,
able to see the person doing the checking.
Pre-Operation Precautions
Fuel Handling
To avoid personal injury or property damage, use
extreme care in handling fuel. Fuel is extremely flammable and the vapors are explosive.
Observe usual fuel handling precautions:
• Do not smoke while refueling. Extinguish all cigarettes, cigars, pipes and other sources of ignition.
• Do not remove fuel cap or fill tank with engine running or while engine is hot. Clean up any fuel spills.
• Allow engine to cool before storing machine inside a
building.
• Keep fuel away from open flame or spark and store
machine away from open flame or spark or pilot light
such as on a water heater or appliances.
• Use extreme care when handling gasoline and other
fuels. They are extremely flammable and vapors are
explosive. A fire or explosion from fuel can burn you
and others and can damage property.
• Refuel outdoors. Never refuel or drain the fuel from the
machine indoors.
• Never attempt to start engine when there is a strong
odor of gasoline or diesel fuel fumes present. Locate
and correct cause.
• Store fuel in an approved container and keep it out of
the reach of children. Never buy more than a 30 day
supply of fuel.
• Do not fill fuel containers inside a vehicle or on a truck
or trailer bed with interior carpets or plastic truck bed
liners. Always place fuel containers on the ground
away from your vehicle before filling.
• When practical, remove gas or diesel fuel powered
equipment from the truck or trailer and refuel the
equipment with its wheels on the ground. If this is not
possible, then refuel such equipment on the truck or
trailer using a portable container and not a fuel dispenser nozzle. If a fuel dispenser nozzle must be used,
keep the nozzle in contact with the rim of the fuel tank
or container opening at all times until fueling is complete. Do not use a nozzle lock-open device.
• Never use gasoline or diesel fuel for cleaning parts.
• Read and observe safety precautions elsewhere in this
manual.
Gasoline and diesel fuel is harmful or fatal if swallowed.
• Long-term exposure to vapors can cause serious injury
and illness.
• Avoid prolonged breathing of vapors.
• Keep face away from nozzle and gas tank or fuel container opening.
• Keep fuel away from eyes and skin.
• If fuel is spilled on clothing, change clothing immediately.
Understand Machine Operation
Only qualified and trained personnel should operate the
equipment.
Carefully read the operator’s manual and all manuals fur-
nished with the attachments. Learn the location and purpose of all controls, instruments, indicators and labels.
Wear Protective Clothing
Do not operate or service the equipment while wearing
sandals, tennis shoes, sneakers, shorts or any type of
loose fitting clothing. Long hair, loose clothing or jewelry may get tangled in moving parts. Always wear long
pants, safety glasses, ear protection and safety shoes
when operating or servicing this machine.
Always wear adequate eye protection when servicing the
hydraulic system and battery, or when grinding mower
blades and removing accumulated debris.
Prolonged exposure to loud noise can cause impairment
or loss of hearing.
• Always wear adequate ear protection, such as earplugs,
when operating this equipment as prolonged exposure
to uncomfortable or loud noises can cause impairme nt
or loss of hearing.
108935BD2-1REV E
Page 8
• Do not wear radios or music headphones while operating the machinery. Safe operation requires your full
attention.
Operation Precautions
Avoid Fire Hazards
Clean flammable material from machine. Prevent
fires by keeping engine compartment, top of deck,
exhaust area, battery, hydraulic lines, fuel line, fuel
tank and operator’s station clean of accumulated
trash, grass clippings, and other debris. Always clean
up spilled fuel and oil.
Start Engine Safely
Avoid possible injury or death from machine runaway.
Do not start engine by shorting across starter terminals.
Before you start the engine:
• Sit on the operator’s seat.
• Move control levers to the neutral/brake position.
Operate Machine Safely
Refer to the unit’s operator’s manual for complete safety
information on safe machine operation.
Always maintain a safe distance from people and pets
when mowing
Always be aware of what is behind the machine before
backing up.
Never leave machine unattended with ignition key in
switch, especially with children present.
Follow daily and weekly checklists, making su re hoses
are tightly secured and bolts are tightened.
Always keep engine and machine clean, removing accu-
mulated dirt, trash and other material from machine.
Never put hands or feet under any part of the machine
while it is running.
Never attempt to start engine when there is a strong odor
of gasoline fumes present. Locate and correct cause.
Keep all safety shields and covers in place, except for
servicing.
Do not touch hot parts of machine.
General Maintenance Precautions
Repairs or maintenance requiring engine power
should be performed by trained maintenance personnel only.
Never run the engine in an enclosed area unless exhaust
is vented to the outside. Exhaust gases contain carbon
monoxide which is an odorless and deadly poison.
Unless specifically required, DO NOT have engine run-
ning when servicing or making adjustments to mower.
Park the machine on level ground. Place steering control
levers in the park brake position, disengage deck clutch,
lower deck, remove ignition switch key and disconnect
negative battery cable before doing any maintenance.
Wait for all movement to st op before adjusting, cleaning
or repairing. To prevent carbon monoxide poisoning, be
sure proper ventilation is available when engine must be
operated in an enclosed area.
Before working on or under the deck, make certain
engine cannot be accidentally started. Shut engine off,
remove ignition switch key and disconnect negative battery cable for maximum safety.
Except when changing or checking belt, always keep belt
covers on mower deck for safety as well as cleanliness.
Use a stick or similar instrument to clean under the
mower making sure that no part of the body, especially
arms and hands are under mower.
Keep your machine clean and remove any deposits of
trash and clippings, which can cause engine fires and
hydraulic overheating as well as excessive belt wear.
Clean up oil or fuel spillage. Allow machine to cool
before storing.
Always wear adequate eye protection when servicing the
hydraulic system and battery, or when grinding mower
blades and removing accumulated debris.
Never attempt to make any adjustments or repairs to the
mower drive system, mower deck or any attachment
while the engine is running or deck clutch is engaged.
Never work under the machine or attachment unless it is
safely supported with jack stands. Make certain machine
is secure when it is raised and placed on the jack stands.
The jack stands should not allow the machine to move
when the engine is running and the drive wheels are
rotating. Use only certified jack stands. Use only appropriate jack stands, with a minimum weight rating of 2000
pounds to block the unit up. Use in pairs only. Follow the
instructions supplied with the vehicle stands.
Keep nuts and bolts tight, especially the blade attachment
bolts. Keep equipment in good working condition.
Never tamper with safety devices. Check their proper
operation regularly.
Exercise caution when working under the deck as the
mower blades are extremely sharp. Wrap the blade(s) or
wear gloves and use extra caution when servicing them.
Use only genuine BigDog
ensure that original standards are maintained.
®
Mower replacement parts to
Maintenance Precautions
Avoid Fire Hazards
Be prepared if an accident or fire should occur. Know
where the first aid kit and the fire extinguishers are
located and how to use them.
Provide adequate ventilation when charging batteries.
Do not smoke near battery.
Never check fuel level with an open flame.
Never use an open flame to look for leaks anywhere on
the equipment.
Never use an open flame as light anywhere on or around
the equipment.
When preparing engine for storage, remember that fuel
stabilizer is volatile and therefore dangerous. Seal and
tape openings after adding the inhibitor. Keep container
tightly closed when not in use.
Inspect electrical wiring for worn or frayed insulation.
Install new wiring if wires are damaged.
REV E2-2108935BD
Page 9
Prepare For Emergencies
Be prepared if a fire starts.
Keep a first aid kit and fire extinguishers available.
Keep emergency numbers for doctor, ambulance service,
hospital, and fire department near the telephone.
Prevent Battery Explosions
Battery posts, terminals, and related accessories contain
lead and lead compounds, chemicals known to the State
of California to cause cancer and reproductive harm.
Wash hands after handling.
Charge batteries in an open well-ventilated area, away
from sparks and flames. Unplug charger before connecting or disconnecting from battery. Wear protective clothing and use insulated tools.
Avoid skin and clothing contact with battery acid.
• Always wear eye protection when checking the battery ,
acid can cause serious injury to skin and eyes. If contact occurs, flush area with clean water and call physician immediately. Acid will also damage clothing.
• Do not drink the battery electrolyte.
• Do not allow open flame near the battery when charg-
ing.
• Hydrogen gas forms inside the battery. This gas is both
toxic and flammable and may cause an explosion if
exposed to flame. Always disconnect the negative
(black) battery cable(s) before disconnecting the positive (red) cable(s). Always connect the positive (red)
battery cable(s) before connecting the negative (black)
cable(s).
• Do not overfill battery.
• Electrolyte may overflow and damage paint, wiring or
structure. When cleaning the battery, use soap and
water. Be careful not to get soap and water into the battery. Clean the battery term inals with a solution of four
parts water and one part baking soda when they
become corroded.
Shorts caused by battery terminals or metal tools touch-
ing metal mower components can cause sparks. Sparks
can cause a battery gas explosion which will result in personal injury.
• Prevent the battery terminals from touching any metal
mower parts when removing or installing the battery.
• Do not allow metal tools to short between the battery
terminals and metal mower parts.
Incorrect battery cable routing could cause damage to the
mower and battery cables. This can cause sparks which
can cause a battery gas explosion which will result in personal injury. Always disconnect the negative (black) battery cable(s) before disconnecting the positive (red)
cable(s). Always connect the positive (red) battery
cable(s) before connecting the negative (black) cable(s).
Avoid Acid Burns
Sulfuric acid in battery electrolyte is poisonous. It is
strong enough to burn skin, eat holes in clothing and
cause blindness if splashed in eyes.
Avoid the hazard by:
• Filling batteries in a well-ventilated area.
• Wearing eye protection and rubber gloves.
• Avoiding breathing fumes when electrolyte is added.
• Avoiding spilling or dripped electrolyte.
If you spill acid on yourself:
• Flush your skin with water.
• Apply baking soda or lime to help neutralize the acid.
• Flush your eyes with water for 10-15 minutes. Get
medical attention immediately.
If acid is swallowed:
• Drink large amounts of water or milk.
• Then drink milk of magnesia, beaten eggs or veget able
oil.
• Get medical attention immediately.
108935BD2-3REV E
Page 10
REV E2-4108935BD
Page 11
TORQUE
WARNING
Standard Torques
The following chart lists the standard torque values for the threaded fasteners found in this manual. Torque all cap screws, nuts and
set screws to these values unless a different torque is shown in the Special Torques section.
1. Lug nuts only – It is recommended that these be checked
after the first 2 hours of operation and every 50 hours and
following removal for repair or replacement.
2. Engine torque values – Refer to the respective engine
owner’s manual.
3. If clutch mounting bolt is loosened or removed, do not
re-use. Replace with a new bolt. Use only hand tools to
install this fastener.
4. If using pin locknut, 250 ft.-lbs.
1
3
4
7095
45 – 4861 – 65
275339
Particular attention must be given to tightening the drive
wheel lug nuts and blade spindle bolts. Failure to correctly torque these items may result in the loss of a wheel
or blade, which can cause serious damage or personal
injury.
108935BD3-1REV E
Page 12
REV E3-2108935BD
Page 13
POWER UNIT MAINTENANCE
WARNING
WARNING
WARNING
Mower
harness
Seat
switch
Female
spades
Shown with steering control
levers in park brake position
Steering Adjustments
Steering control lever neutral adjustment
The mower’s steering has been factory adjusted to eliminate
creeping when the steering control levers are in the neutral position. However, should the mower begin to creep, the steering
control lever linkage can be adjusted.
Before considering any adjustment, check the tire air pressure.
Unequal tire pressure will cause the mower to drift to one side.
Refer to tire pressure information in the Tires section for
detailed information.
NOTE: Proper park brake adjustment must be completed
before the steering control lever neutral adjustment can be done.
Refer to the Park Brake Spring Adjustment section for detailed
information.
Fine adjustment to the unit’s steering is made with the transmission’s control rod.
Neutral is properly adjusted when the steering control levers
are in the park brake position and the transmissions do not
“whine”.
If this occurs, the steering control linkage may be adjusted as
follows:
3. Raise the seat platform and disconnect the mower harness
from the seat switch. Bypass the seat switch by
connecting the two mower harness female spades
together. Figure 4-1
This procedure will require that the unit to be raised and
blocked up off of the ground. It is necessary for the
wheels to rotate without coming in contact wi th the floor
or any object that would permit the unit to propel it self.
Stay clear and exercise caution when rotating wheels to
prevent injury. Use only appropriate vehicle stands, with
a minimum weight rating of 2000 pounds to block the
unit up. Use in pairs only. Follow the instructions supplied with the vehicle stands.
Keep hands, hair, clothing, etc., clear of the cooling fans
on top of the transmissions. Exercise extreme caution.
Untrained maintenance personnel should never attempt to
make any adjustments or repairs to the mower’s drive
system while the engine is running. The following proce-
dures should be performed by trained maintenance
personnel only.
Figure 4-1
4. Loosen the jam nuts on each end of the steering control
rod assemblies. Figure 4-5
5. Set both steering control levers in the park brake position.
Figure 4-2
NOTE: Both steering control levers need to be in the
park brake position when starting the engine but need to
be moved rapidly out of the park brake position once
engine is started so that the brakes do not fight the
transmissions since they have not yet been adjusted.
1. Raise the rear of the mower and block with certified jack
stands. The rear wheels need to be able to rotate freely
and clear of all obstructions.
2. Chock the front tires.
108935BD4-1REV E
Figure 4-2
Page 14
6. Loosen the nuts on the rear steering damper ball studs.
WARNING
Steering control lever
Shown with steering control
levers in neutral position
WARNING
WARNING
Align handles
± .125”
The dampers must be allowed to slide in the slots in the
mower frame. Figure 4-5
7. Start the engine. Move the steering control lever to barely
engage the brake (neutral) slot and hold it in that position
(Do not engage the steering control lever far enough to
engage the brakes in the brake slot) (Figure 4-3).
This operation is extremely dangerous. Pay close attention when adjusting the transmission control rod so you
do not get your fingers, tools, or anything else close to the
transmission’s cooling fans.
8. Beginning with the right side of the mower, adjust the
steering control rod so that the right side wheel starts
rotating forward while holding the steering control lev er
in the neutral position. Now, adjust the steering rod back
the opposite direction to the point when the wheel stops
rotating. From that point, turn the steering rod back again
½ turn. This ensures that the steering rod is adjusted so
that the transmission control arm is centered in the
neutral band of the transmission. Figure 4-5
nut is tightened, when the steering control lever is in the
reverse position and then released, the steering control
lever should return to the neutral position. Figure 4-5
12. Check to make sure you have all fasteners tightened to
the correct torque specifications.
13. Repeat steps 4 thru 12 for the left side.
14. Once both sides are properly adjusted, check them
together to make sure everything is working properly.
15. IMPORTANT: With the engine off, disconnect the two
female spade connectors from each other (from step #3)
and reconnect them to the seat switch. This must be
completed so that the safety circuit is functioning
properly. Figure 4-1
Do not operate the mower without plugging the mower ’s
wiring harness into the seat switch. This switch is an
important part of the safety start interlock system. Serious
injury can result if the seat switch is not plugged into the
mower’s wiring harness.
Figure 4-3
9. Move the steering control lever forward and backward
making sure that the wheel rotates forward and backward
correctly. Return the steering control lever to ne utral and
re-check to make sure the wheel has stopped in the
neutral position. Place the steering control lever in the
park brake position.
NOTE: If neutral is set properly, you should not hear the
transmission whine.
10. Turn the engine off.
11.With the engine off, move the right side steering control
lever into the neutral position and pull the lever to the full
reverse position. Now, slowly bring the steering control
lever back to the neutral position and then place it in the
park brake position. This sets the steering damper in the
correct neutral position.
Tighten the nut on the damper’s rear ball stud. Once this
Never operate the mower with a non-functioning seat
switch. Always reconnect the seat switch to the mower
harness.
16. The steering control levers should be adjusted so that
they align vertically with each other when in the neutral
position (Figure 4-3). Space between ends of steering
control handles to be .50” ±.25”. Figure 4-4
17. Check to make sure all tools or obstructions are removed
from under the mower.
18. Raise the rear of the mower and remove the jack stands.
Lower the mower.
Figure 4-4
REV E4-2108935BD
Page 15
Steering damper
Steering
damper
Steering
damper
stud
Nut
Slot
Jam
nut
Jam
nut
Steering
control
rod
Steering
control
lever
Seat
latch
Bolt
Torque to
17 ft.-lbs.
Slot
Seat
platform
The steering damper is spring loaded to return the steering
control levers to the neutral position from the reverse position.
This gives the operator a sense of neutral during operation.
If the mower does not return to neutral from reverse then
adjust as follows:
To set the steering dampers in the correct operating position
follow these steps:
1. Shut engine off, place steering control levers in the park
brake position, disengage deck clutch, and remove
ignition switch key.
2. Raise seat platform and disconnect negative battery cable
before doing any adjustments.
3. Place the steering control lever in the neutral position.
Figure 4-3
4. Loosen the steering damper’s rear ball stud. Figure 4-7
5. Pull the damper spring housing, to the rear, past the point
that the internal spring is engaged.
6. Release the damper spring housing and allow the internal
spring to bring the housing back to the neutral position.
7. Tighten the nut on the steering damper’s rear ball stud.
Figure 4-7
8. Reconnect the negative battery cable.
9. Lower the seat platform making sure that it is secured
properly with the latch.
NOTE: If you have the seat latch shown in Figure 4-6,
lower the seat platform and re-install latch. Make sure the
108935BD4-3REV E
seat latch is properly seated in the slot in the mower’s
crossmember. Torque seat latch bolt to 17 ft .-lbs. .
Figure 4-5
10. To check, move the steering control lever to the reverse
Figure 4-6
position and release. The steering control lever should
return to the neutral position. If not, repeat steps 1
Page 16
through 7.
WARNING
Steering
damper
WARNING
Nylock nut
Brake arm
spring
1
.
4
3
7
”
Bottom View
Hydraulic pump belt
Tension idler
Spring
Never operate the mower with the seat latch un-installed
or not properly secured. The seat platform must be
securely latched to prevent seat from moving/tilting in the
event of mower tipping or rollover.
Figure 4-7
Figure 4-8
Hydraulic Pump Belt Adjustment
The transmission drive belt tension remains constant by
means of a tension idler and spring. There is no tension adju stment of this belt. Figure 4-9
NOTE: Inspect the belt every 100 hours and replace as
needed. Replace the belt every 200 hours or every two (2) years
whichever comes first.
Park Brake Spring Adjustment
Occasionally check the park brake spring adjustment using
the following method:
1. Shut engine off, place steering control levers in the park
brake position, disengage deck clutch, remove ignition
switch key and disconnect negative battery cable before
doing any adjustments.
2. On one side measure the park brake spring. It should be
compressed to 1.437”. If it is not, adjust the nylock nut
until the proper spring compression is achieved. Figure 48
3. Repeat for other side.
4. Reconnect the negative battery cable.
Belts
Inspect belts frequently for wear and serviceability. Replace a
belt that shows signs of severe cuts, tears, separation, weather
checking and cracking, or burns caused by slipping. Slig ht raveling of belt covering does not indicate failure, trim ravelings
with a sharp knife.
Inspect the belt pulley grooves and flanges for wear. A new
belt, or one in good condition, should never run against the bottom of the groove. Replace the pulley when this is the case, otherwise belt will lose power and slip excessively.
Never pry a belt to get it on a pulley as this will cut or damage
the fibers of the belt covering.
Keep oil and grease away from belts, and never use belt dressings. Any of these will destroy the belt composition in a very
short time.
If the transmission belt fails, loss of control will occur
especially when operating on a slope. If you lose steering
control while operating the machine, place the steering
control levers in the park brake position immediately.
Inspect the machine and involve your dealer to resolve
the problem.
Figure 4-9
Hydraulic System
The BigDog® R Series mowers are equipped with two trans-
REV E4-4108935BD
Page 17
axles. Figure 4-10
WARNING
Transaxles
Expansion
tank
Transaxle filter
Screw
Screw
Filter
guard
IMPORTANT: Never use hydraulic or automatic transmis-
sion fluid in this system; use only motor oil as specified.
Remember, dirt is the primary enemy of any hydraulic system.
The hydraulic expansion tank is located in front of the engine
and under the operator’s platform. Figure 4-10
Check oil level in hydraulic system after every 50 hours of
operation or weekly, whichever occurs first. Check more often if
system appears to be leaking or otherwise malfunctioning.
Fluid level should be at the “Full Cold” line on the expansion
tank. Use only SAE 20W50 SL/SM service motor oil.
Initial system oil and filter change must be after the first 75
hours of use or 1 year whichever comes first. Thereafter, replace
filter and oil in each transaxle every 2 years or 200 hours,
whichever comes first. NOTE: The filter guard must be
removed to access filter.
Each transaxle’s filter is located per Figure 4-11. A standard
oil filter wrench is used to change filter, threads are right
handed. Use a BigDog
®
Mowers approved filter element only.
Purging procedures must be followed after changing the oil
and filter. Refer to Purging Procedure section for detailed information.
Figure 4-11
When washing the mower, direct the spray away (especially if using a power washer) from the transaxle’s seals
to prevent water intrusion and to ensure component performance.
Figure 4-10
Fluid changing procedure
1. Park the unit on a level surface. Place control levers in
the park brake position, disengage deck clutch, remove
ignition switch key and disconnect negative battery
cable.
2. Remove the three 1/4” filter guard screws and filter
guard. Clean any loose debris from around the filter
Figure 4-12
3. Place an oil drain pan beneath the oil filter and remove
the oil filter from the transaxle.
108935BD4-5REV E
Figure 4-12
4. After the oil has been drained, wipe the filter base surface
off and apply a film of new oil to the gasket of the new
replacement filter.
5. Install the new filter by hand, turn 3/4 to one full turn
after the filter gasket contacts the filter base surface.
6. Re-install the filter guard with three 1/4” screws. Torque
the screws to 65 in.-lbs. each. Figure 4-12
7. Repeat steps 2 - 6 for the opposite side transaxle.
8. Drain oil filters of all free flowing oil prior to disposal.
Place used oil in appropriate containers.
9. IMPORTANT: Remove the top port plug from both
transaxles prior to filling with oil. This will allow the
transaxles to vent during oil fill. Figure 4-13
10. Remove the cap from the transaxle's expansion tank.
11.Fill with 20W50 motor oil until oil just appears at the
bottom of each transaxles top port (approximately 2 qts.
per transaxle). Install the top port plug into each transaxle
as the oil level reaches this port. Torque plugs to 180 in.
lbs. Clean up any oil that leaked from the ports. Figure 413
12. Continue to fill the transaxles through the expansion tank
until the “Full Cold” line is reached on the expansion
Page 18
tank.
Top port plug
WARNING
Steering control lever
Shown with steering control
levers in neutral position
13. Re-install the expansion tank cap by hand. Be careful not
to overtighten.
14. Proceed to the purge procedure.
Figure 4-13
Never work under the machine or attachment unless it is
safely supported with jack stands.
Make certain machine is secure when it is raised and
placed on the jack stands. The jack stands should not
allow the machine to move when the engine is running
and the drive wheels are rotating. Use only certified jackstands. Use only appropriate jack stands, with a minimum weight rating of 2000 pounds to block the unit up.
Use in pairs only. Follow the instructions supplied with
the vehicle stands.
Purging procedure
Due to the affects air has on efficiency in hydrostatic drive
applications, it is critical that it is purged from the system.
Air creates inefficiency because its compression and expan-
sion rate is higher than that of the oil approved for use in hydrostatic drive systems.
These purge procedures should be implemented any time a
hydrostatic system has been opened to facilitate maintenance or
the oil has been changed.
The resulting symptoms in hydrostatic systems may be:
1. Noisy operation.
2. Lack of power or drive after short term operation.
3. High operation temperature and excessive expansion of
oil.
Before starting, make sure the transaxle is at the proper oil
level. If it is not, fill to the specifications outlined in this manual.
The following procedures are best performed with th e vehi cle
drive wheels off the ground. Then repeated under normal operating conditions. If this is not possible, then the procedure
should be performed in an open area free of any objects or
bystanders.
1. Raise and block the mower up so the drive wheels are off
of the floor.
2. Position the control lever in the neutral position.
Disengage the deck clutch switch. Figure 4-14
3. With the bypass valve open and the engine running,
slowly move the directional control in both forward and
reverse directions (5 or 6 times). Figure 4-15
4. With the bypass valve closed and the engine running,
Figure 4-14
slowly move the control lever in both forward and
reverse directions (5 or 6 times). Check the oil level, and
add oil as required after stopping the engine.
5. It may be necessary to repeat Steps 3 and 4 until all the
air is completely purged from the system. When the
transaxle operates at normal noise levels and moves
smoothly forward and reverse at normal speeds, then the
transaxle is considered purged.
Tires
It is important for level mowing that the tires have the same
amount of air pressure. The recommended pressures are:
If you wish to use non-pneumatic tires on your BigDog
mower the tires must be an approved tire purchased from
BigDog
mower equipped with unapproved non-pneumatic tires.
®
Mowers. Warranty claims will be denied on any
®
REV E4-6108935BD
Page 19
Figure 4-15
(Right rod shown)
Bypass valve rod shown
in operating position
108935BD4-7REV E
Page 20
REV E4-8108935BD
Page 21
ENGINE MAINTENANCE
WARNING
Oil drain valve
Oil drain hose
General Engine Maintenance
Detailed instructions and recommendations for break-in and
regular maintenance are specified in the Engine Owner’s manual. Please refer to this manual for engine servicing, lubricating
oil levels with quality and viscosity recommendations, bolt
torques, etc. The engine warranty is backed by the manufacturer .
Engine Oil and Filter
If the engine has been running and is up to operating temperature, allow the engine to cool before changing the oil.
Engine and engine oil will be very hot, so be very careful
when changing oil and wear the appropriate protective
gear to avoid being burned or exposed to engine oil.
Check engine oil daily and after every 4 hours of operation.
Mower must be on a level surface when checking oil. Refer to
engine manual and maintenance schedule for oil recommendation and capacities.
Change the engine oil and filter after the first 5 hours of operation and then per the engine manufacturer’s recommendations
after that. If mower is being operated in extremely dirty conditions, then it is recommended oil be changed more frequently.
IMPORTANT: When removing the oil filter take precau-
tions to minimize oil spillage on the exhaust system.
Draining the engine oil (units equipped with oil drain
valve as shown in Figure 5-1):
1. Locate the oil drain valve on the lower left side of the
engine.
2. Remove the dust cap.
3. Locate the oil drain hose that was supplied with the
machine. Be sure to clean and clear it of debris that might
block the flow of the engine oil. Figure 5-2
4. Attach one end of the hose onto the oil drain valve nipple.
Make sure the hose is pushed all the way onto the valve.
5. Position the loose end of the hose out to the left side of
the mower so that it can drain into a suitable oil drain
container.
6. With the hose in position, twist the valve
counterclockwise and pull out to open the valve. Allow
10 minutes for engine oil to adequately drain.
7. After oil is drained, close the valve by pushing in on the
valve body and twisting it clockwise.
8. Once the valve is closed, carefully remove the oil drain
9. Re-install the dust cap on the oil drain valve nipple.
10. Clean the oil drain hose and store it appropriately. Figure
hose and clean up any spilled oil.
IMPORTANT: All oil drips or spills must be cleaned off
of the exhaust system before operating the machine.
5-2
Figure 5-1
Figure 5-2
Draining the engine oil (units equipped with oil drain
valve as shown in Figure 5-3):
1. Locate the oil drain valve on the engine. Figure 5-3
2. Position a suitable oil drain container under the machine
below the oil drain valve.
3. Twist the valve counterclockwise to open the valve.
Allow 10 minutes for engine oil to adequately drain.
4. After oil is drained, close the valve by twisting it
clockwise.
5. Once the valve is closed, clean up any spilled oil.
IMPORTANT: All oil drips or spills must be cleaned off of
the exhaust system before operating the machine. .
Engine Air Filter
Perform engine air filter maintenance per the engine’s
owner’s manual.
Fuel Evaporation System Filter
108935BD5-1REV E
Some mowers have a fuel evaporation system filter. This filter
Page 22
Figure 5-3
Oil drain valve
Fuel
tank
Fuel
tank
Seat support
Fuel evaporation
system filter
Fuel line
Fuel
shutoff
valve
Fuel
tank
Fuel
tank
Fuel line
Seat support
Fuel
tank
Fuel
tank
Seat support
Vapor line
Vapor line
must be checked and replaced every 300 hours or annually
whichever comes first. Figure 5-4
Figure 5-4
NOTE: Mowers produced after serial number 12050900 and
with an EX or AU extension after the model number do not have
a fuel evaporation system filter.
Figure 5-5
Figure 5-6
NOTE: Mo wers produced after serial number 12050900 and
with an EX or AU extension after the model number do not have
a fuel evaporation system.
Fuel & Evaporative System Line Routings
On mowers that have a fuel evaporative system installed there
are two rubber hoses that are connected to each fuel tank. One is
the fuel hose that is part of the fuel system. The other is the
vapor line that is part of the fuel evaporative system.
The fuel hose is connected to the port on the side wall of the
fuel tank. It connects the fuel tank to the fuel shutoff valve.
Figure 5-5
The vapor line is connected to the port in the top of the fuel
tank. It connects the fuel tank to the engine’s vapor port. Figure
REV E5-2108935BD
Page 23
Engine RPM Settings
The engine rpm’s are set at the factory for maximum mowing efficiency. Occasionally it may be necessary to check and adjust the
settings. The idle speeds should be set as follows:
B&S 21 hp
ENGINE SPEED
MODEL NO. ENDING WITH:HIGH IDLE
MODEL NO. WITHOUT EXTENSION
MODEL NO. WITH EX EXTENSION
MODEL NO. WITH AU EXTENSION
3600 ± 50 RPM
B&S 26 hp
ENGINE SPEED
MODEL NO. ENDING WITH:HIGH IDLE
MODEL NO. WITHOUT EXTENSION
MODEL NO. WITH EX EXTENSION
MODEL NO. WITH AU EXTENSION
3600 ± 50 RPM
Kohler SV715
ENGINE SPEEDS
MODEL NO. ENDING WITH:HIGH IDLE
MODEL NO. WITHOUT EXTENSION
MODEL NO. WITH EX EXTENSION
MODEL NO. WITH AU EXTENSION
3600 ± 50 RPM
Kawasaki FR651 / FR691 / FR730
Engine Speed
Model No. ending with:high idle
MODEL NO. WITHOUT EXTENSION
MODEL NO. WITH EX EXTENSION
MODEL NO. WITH AU EXTENSION
3600 ± 50 RPM
NOTE: Model numbers may or may not end with an extension after the number. There are several different extensions that may be
shown; i.e. EX or AU.
Example: 922222 (no extension)
922222 EX
922222 AU
108935BD5-3REV E
Page 24
REV E5-4108935BD
Page 25
DECK ADJUSTMENTS
WARNING
Block
Block
Block
Block
Nuts
Height in-
dicator bar
Lift block
Clamp here
Nuts
Deck lifting rod
1”
Deck lifting chain
Deck Leveling
Leveling the deck must be done in the following m anner and
order:
1. Check tire pressures to make certain they are properly
inflated before starting to level deck. The recommended
pressures are as follows:
Stop engine. Make sure deck clutch switch is in the down(OFF) position. Place control levers in the brake position
before leaving machine.
2. Park the unit on a flat surface.
3. Place 3” high deck support blocks (two stacked 2” x 4”
blocks can be used to create a 3” high support) at the four
corners of the deck as shown. NOTE: Back of deck will
automatically be set 1/4” higher. Figure 6-1
4. Place the height stop in the 3” hole, with the flat side of
the height adjusting stop against the stop handle.
Figure 6-2
Figure 6-1
5. Clamp the height adjusting stop against the stop handle.
This will assure that the height will not move du ring the
setting process. Otherwise, spring pressure from the deck
lift springs will tend to pull the stop away from the
handle. Figure 6-2
6. Loosen all nuts on the deck lift threaded rods, and the
hardware on the height indicator bar (on the right front),
until all the deck lift chains are loose, and the deck is
sitting tightly on all four blocks. Figure 6-2, Figure 6-3 &
Figure 6-4
7. Loosen the two nuts on the front of height indicator so
that the foot pedal is free. Figure 6-2
8. Set the amount of threads protruding on the deck li ft rod
from the lift block at approximately 1" (left & right side).
Figure 6-3
108935BD6-1REV E
Figure 6-3
10. Start the leveling process on the left front of the deck.
11.Push or pull on the deck lift foot pedal until the chain on
the left front just becomes tight, making sure that the
deck stays tight against the block.
12. While keeping the chain tight, tighten the nuts against the
deck lift block on the height indicator rod, just enough to
carry most of the deck weight on that side — the block
should be able to move with only a slight drag. Figure 6-2
13. Jam nuts tightly together against the deck lift block.
14. Go to the right front of the deck.
15. Loosen the hardware that clamps the adjuster to the deck
lift arm. Figure 6-4
16. Loosen the 5/16" jam nut on the adjuster lift chain, and
back the adjuster bolt out to allow the adjuster to move
up and down freely. Figure 6-4
17. Tighten the adjuster bolt until the chain just becomes
tight. Then tighten just enough to carry the weight of the
front of the deck on that side—to check, move the blocks
back and forth; they should move with a slight drag.
Figure 6-1
18. Tighten the adjuster bolt jam nut to prevent the adjuster
Page 26
bolt from moving. Figure 6-4
Jam Nut
Deck lift arm
Adjuster bolt
Chain
Flange nuts
Adjuster
Jam Nut
Chain
WARNING
WARNING
Jam Nut
1/2”
19. Tighten the hardware holding the chain and adjuster onto
the deck lift arm.Figure 6-4
Figure 6-4
20. Go to the right rear of the deck.
21. Make sure that there is still slack in the chain. If not,
loosen the two nuts on the block holding the threaded rod
until there is slack in the deck lift chain. Figure 6-5
22. Tighten the appropriate nut until the chain just becomes
tight, and carries most of the deck weight. Check by
moving the block—it should move with a slight drag.
Figure 6-1
23. Tighten the other nut on the opposite side of the block,
and jam them tightly together against the block.
and jam them tightly together against the block.
28. Compress the deck lift assist springs so that there is 1/2”
of space between the front nut on the spring and the rear
nut on the deck lift block. Typical both sides. Figure 6-6
29. When completed, all chains will be tight, and deck
cutting height will be set to the deck height indicator.
Figure 6-6
Blades
Mower blade maintenance
Check the mower blades daily, they are the key to power efficiency and well groomed turf. Keep them sharp, a dull blade
will tear rather than cut the grass, leaving a brown ragged top on
the grass within a few hours. A dull blade also requires more
power from the engine. Figure 6-7
Replace any blade which is bent, cracked or broken. Figure 68 & Figure 6-9
Figure 6-5
24. Go to the left rear of the deck
25. Make sure that there is still slack in the chain. If not,
loosen the two nuts on the block holding the threaded rod
until there is slack in the deck lift chain. Figure 6-5
26. Tighten the appropriate nut until the chain just becomes
tight, and carries most of the deck weight. Check by
moving the block—it should move with a slight drag.
Figure 6-1
27. Tighten the other nut on the opposite side of the block,
REV E6-2108935BD
Never attempt to straighten a bent blade by heating, or
weld a cracked or broken blade as the blade may break
and cause serious injury. Replace worn or damaged
blades.
Never work with blades while engine is running or deck
clutch switch is engaged (on). Always place deck clutch
switch in the disengaged position, place steering control
levers in the park brake position and turn engine off and
disconnect negative battery cable. Block up mower when
you must work under it. Wear gloves when handling
blades. Always check for blade damage if mower strikes
a rock, branch or other foreign objects during mowing!
Page 27
WARNING
Always wear adequate eye protection when grinding
WARNING
Resharpening
pattern
Do not sharpen to original pattern (below). It is
easier to get a straight cutting edge following
the resharpening pattern shown above.
Original edge
WARNING
WARNING
Warped Blade (Replace)
Straight Blade
Cutting
plane
Comparison of Warped and Straight Blades
Cutting edge
Twisted Blade Edge
(replace)
Cutting edgeCutting Plane
Straight Blade Edge
End view of blades, comparing
twisted and straightened blades
mower blades.
Mower blades are sharp and can cut. W ear gloves and use
extra caution when servicing them.
Always place deck clutch switch in the disengaged position,
place steering control levers in the park brake position and turn
engine off and disconnect negative battery cable. Block up
mower when you must work under it. Wear gloves when handling blades. Always check for blade damage if mower strikes
a rock, branch or other foreign objects during mowing!
Spin the blade slowly, blade should not wobble. If blade is out
of balance, true it up before reinstalling.
Lay the blade on a flat surface and check for distortion
(Figure 6-8 & Figure 6-9). Replace any distorted blade.
Do not re-use spindle bolts which have stripped, worn or
undercut threads. Torque bolts on spindles to 118 foot-pounds
(160.0 Nm) when reinstalling blades.
Properly compressed cup washers maintain the correct
compression load on the blades. Replace the cup washers if they
are cracked or flattened.
IMPORTANT: The blade sail (curved part) must be point-
ing upward toward the inside of the deck to ensure proper cutting.
IMPORTANT: When mounting blades, rotate them after
installation to ensure blade tips do not touch each other or sides
of the mower.
Failure to correctly torque the bolt may result in the loss
of the blade which can cause serious injury.
Figure 6-7
Mower blade removal
Use a 15/16” wrench to remove the 5/8” cap screw holding
the blade to the spindle shaft from underneath. NOTE: A blade
holding tool (part number 381442) is available from BigDog
Mowers. It is designed to prevent the blades from rotating when
they are being removed or installed on the spindle. Contact your
BigDog
(Figure 6-7). Touch-up sharpening can be done with a file
commercial balancing tool is available through most hardware
®
Mowers dealer for more information.
Sharpen the blades on a grinder following pattern as shown
Check the blades for balance following grinding. A
supply stores, or balancing can be done by placing the blade on
an inverted line punch or 5/8” bolt. Blade should not lean or tilt.
108935BD6-3REV E
Mower blades are sharp and can cut. Wrap the blade(s) or
wear gloves and use extra caution when servicing them.
Figure 6-8
®
Figure 6-9
Belts
Inspect belts frequently for wear and serviceability. Replace a
belt that shows signs of severe cuts, tears, separation, weather
Page 28
checking and cracking, or burns caused by slipping. Slig ht rav-
Spring chain
Spring chain
anchor point
Idler
spring
eling of belt covering does not indicate failure, trim ravelings
with a sharp knife.
Inspect the belt pulley grooves and flanges for wear. A new
belt, or one in good condition, should never run against the bottom of the groove. Replace the pulley when this is the case, otherwise belt will lose power and slip excessively.
Never pry a belt to get it on a pulley as this will cut or damage
the fibers of the belt covering.
Keep oil and grease away from belts, and never use belt dressings. Any of these will destroy the belt composition in a very
short time.
Deck Belt Adjustment
The spindle belt tension remains constant by means of a tension idler and spring. The spring tension should be su ch t hat the
belt does not slip under normal operating load conditions,
assuming the belt is not excessively worn or damaged. As the
belt stretches and wears in, adjustment may become necessary.
To increase belt tension, mov e the spring chain one (or more)
link(s) at the anchor point on the deck frame. Figure 6-10, Figure 6-11, & Figure 6-12
IMPORTANT: Do not over tension the spring to compensate
for a badly worn belt or pulley.
Figure 6-10
REV E6-4108935BD
Page 29
NOTE: The following notes are the same for the different decks shown.
8.3” – 9.3”
8.25” – 9.25”
1. Spring length after tensioning new belt. Measured from outside of hook to outside of hook with deck set at 3¼" cut height.
Verify safety start interlock systemPrior to each use
Visually inspect unit for loose hardware and/or damaged partsPrior to each use
Visually inspect tiresPrior to each use
Check oil level, engine (1)Prior to each use or every 4 hours
Clean air intake screen (4)Prior to each use or every 4 hours
Check fuel levelPrior to each use
Blades - sharpen & securely fastenedPrior to each use
Discharge chute - securely in place & in lowest positionPrior to each use
Replace air cleaner paper element (if equipped)As needed
Clean engine and transaxle compartmentDaily
Change transaxle oil and filter (7)Every 200 hours or 2 years
Grease deck height pivotsX
Grease front wheel bearingsX
Change engine oil and filter (1) (3)X
Check battery connectionsX
Check tire pressure with a gaugeX
Check hydraulic oil levelX
Clean engine exterior (a)X
Check pump and deck belt tension
and condition (5)X
Check fuel and hydraulic lines (6)X
Check fuel valve and grommet (6)X
Tighten lug nuts on wheels (2)X
Change fuel filter (6)X
Check ROPS mounting hardware (9)X
Replace fuel evaporation system filter (8)X
WEEKLY
OR 40
HOURS
MONTHLY
OR 100
HOURS
ANNUALLY
OR 300
HOURS
NOTES:
1. Initial oil change is after 5 hours of operation. Thereafter, change oil after every 40 hours operation. Change more often under dusty or dirty conditions and during
hot weather periods.
2. Torque initially and after first 2 hours of operation.
3. Change engine oil filter per the engine manufacturer’s recommendations. Refer to Engine Owner’s Manual for recommendations and other maintenance items.
4. Service more often under dusty or dirty conditions.
5. Pump drive belt only - Inspect every 6 months or 100 hours and replace if worn or if cracking is noticed. Othe rwise, replace every 200 hours or 2 years
whichever comes first.
6. Check fuel system for any cracks or leaks including, but not limited to, fuel line hoses, fuel valve, vent line hoses, vent valve, vapor valve, carbon canister, and
grommets. Repair as needed.
7. Initial system oil and filter change must be after the first 75 hours of use or 1 year whichever comes first. Thereafter, replace filter and oil in each transaxle every
2 years or 200 hours, whichever comes first.
8. More often under dusty or dirty conditions and during hot weather.
9. Inspect ROPS after the first 20 hours of operation and then after every 500 hours of operation or yearly whichever comes first.
REFERENCES:
A. Refer to Engine Owner’s Manual
NOTE: After completing maintenance cycle (300 hours), repeat cycle.
108935BD8-1REV E
Page 34
Maintenance Locator Chart
6
5
4
3
2
1
6
17
10
14
14
9
8
9
8
4
7
7
12
13
13
1
15
16
16
16
Figure 8-1
1. Engine Oil Fill & Dipstick
2. Fuel Filter
3. Engine Air Cleaner
4. Engine Oil Drain Valve
5. Battery
6. Fuel Tank
7. Engine Oil Filter
8. Deck Lift Pivot Zerks (4)
9. Park Brake Switch (2)
10. Drive Tire
11. Pump Belt
12. Engine Air Intake Screen
13. Front Wheel Tires
14. Front Wheel Zerks (2)
15. Deck Belt
16. Blades
17. Hydraulic Oil Expansion Tank
18. Hydraulic Oil Filter
19. Fuel Evaporation System Filter
Figure 8-2
REV E8-2108935BD
Page 35
Figure 8-4
18
18
10
10
11
19
Figure 8-3
1. Engine Oil Fill & Dipstick
2. Fuel Filter
3. Engine Air Cleaner
4. Engine Oil Drain Valve
5. Battery
6. Fuel Tank
7. Engine Oil Filter
8. Deck Lift Pivot Zerks (4)
9. Park Brake Switch (2)
10. Drive Tire
11. Pump Belt
12. Engine Air Intake Screen
13. Front Wheel Tires
14. Front Wheel Zerks (2)
15. Deck Belt
16. Blades
17. Hydraulic Oil Expansion Tank
18. Hydraulic Oil Filter
19. Fuel Evaporation System Filter
108935BD8-3REV E
Page 36
REV E8-4108935BD
Page 37
TROUBLESHOOTING
SYMPTOMSPROBABLE CAUSES
Starting motor does not
crank
The engine will not start,
starts hard or fails to keep
running
Engine:
Runs with continuous misfiring or engine runs
unevenly or erratically
Loss of power or system
will not operate in either
direction
OverheatingAir intake screen or cowl-
Low engine oil pressureLow oil levelAdd oil
High oil consumptionNumerousSee your dealer
Mower jerky when starting
or
operates in one direction
only
Steering control levers not
in park brake position or
switch not adjusted
Deck clutch switch
engaged
Weak or dead batteryRecharge or replace
Electrical connections are
corroded or loose
25 amp fuse is blownReplace the 25 amp
For additional causesSee engine manual
No fuel or line pluggedFill tank or replace line
Fuel valve is turned offOpen the fuel valve
There is incorrect fuel in
the fuel system
There is dirt in the fuel filter
Dirt, water or stale fuel in
the fuel system
The choke is not onMove the choke lever to
NumerousSee engine manual
NumerousSee engine manual
Restrictions in air cleanerService air cleaner
Poor compressionSee your dealer
Steering linkage needs
adjustment
Tow valve openClose tow valve
The traction drive belt is
worn, loose or broken
For additional causesSee engine manual
ing fins clogged
For additional causesSee engine manual
Oil diluted or too lightChange oil and check for
Steering control linkage
needs adjustment
Loose steering linkageTighten linkage
Transmission component
faulty
SUGGESTED
REMEDIES
Place steering control
levers in park brake position or re-adjust switch
Disengage clutch switch
Check the electrical connections
fuse
Drain the tank and replace
the fuel with the proper
type
Replace the fuel filter
Contact your BigDog®
Mowers Dealer
ON
Adjust linkage
Install a new traction drive
belt
Clean screen and fins
source of contamination
Adjust linkage
See your dealer
SYMPTOMSPROBABLE CAUSES
Mower creeps when
steering control levers are
in neutral
Mower circles or veers in
one direction
There is abnormal vibration
Uneven cutting heightThe blade(s) are not
Blades do not rotateThe deck drive belt is
Steering linkage needs
adjustment
Steering linkage needs
adjustment
Loose steering linkageTighten linkage
Tires improperly inflatedAdjust air pressure to 8 -
Transmission component
faulty
The engine mounting
bolts are loose
The engine pulley, idler
pulley or blade pulley is
loose
The engine pulley is damaged
The cutting blade(s) is/are
bent or unbalanced
A blade mounting bolt is
loose
Spindle bearing is w orn or
loose
A blade spindle is bent
sharp
A cutting blade(s) is/are
bent
The deck is not levelLevel the deck per the
An anti-scalp wheel is not
set correctly
The underside of the deck
is dirty
Tires improperly inflatedAdjust air pressure to 8 -
A blade spindle is bent
worn, loose or broken
The deck drive belt is off
the pulley
Electric clutch is not
engaging
SUGGESTED
REMEDIES
Adjust linkage
Adjust linkage
12 psi (55 - 83 KPa)
See your dealer
Tighten the engine mounting bolts
Tighten the appropriate
pulley
Contact your BigDog®
Mowers Dealer
Install new cutting
blade(s)
Tighten the blade mounting bolt
Replace or tighten spindle
bearing
Contact your BigDog®
Mowers Dealer
Sharpen the blades
Install new cutting
blade(s)
Deck leveling and height
adjustment section of the
parts manual
Adjust the height of the
anti-scalp wheel
Clean the underside of the
deck
12 psi (55 - 83 KPa)
®
Contact your BigDog
Mowers Dealer
Install a new deck drive
belt
Install the deck drive belt
and check for a reason