BigDog ALPHA User manual

119293 REV E
BIG DOG®MOWER CO. ALPHA®
General Service Manual
200 South Ridge Road
Hesston, Kansas
67062

REV E 119293
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 removed 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 Requirements. 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.

119293 toc-1 REV E
TABLE OF CONTENTS
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Big Dog®Mowers Service Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Maintenance Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Safety. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Safe Servicing Practices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Pre-Operation Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Operation Precautions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Operate Machine Safely . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
General Maintenance Precautions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Maintenance Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Torque . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Standard Torques. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Special Torques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Power Unit Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Steering Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Park Brake Spring Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
Transaxle Drive Belt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
Engine Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
General Engine Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
Engine Oil and Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
Engine Air Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
Fuel Evaporation System Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
Fuel and Evaporative System Line Routing . . . . . . . . . . . . . . . . . . . . . . 5-2
Engine RPM Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
Deck Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
Deck Leveling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
Blades . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
36"/42" Deck Belt Routing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10
52" Deck Belt Routing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10
Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
Electrical Schematic — Kawasaki . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
Electrical Schematic — Kawasaki . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

REV E toc-2 119293
Electrical Schematic — Kohler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1
Maintenance Locator Chart. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1

119293 1-1 REV E
GENERAL INFORMATION
Big Dog®Mowers Service Program
This manual is part of a service package for the Big Dog®
ALPHA®mowers. Use of this manual in conjunction with
other Big Dog®mower and component manuals will provide
the information necessary to service and maintain the Big
Dog®ALPHA®mower.
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 oper-
ating the mower.
The component manuals are furnished by the various man-
ufacturers to be used for the troubleshooting and servicing
of their components.
Maintenance Introduction
Regular maintenance is the best prevention for downtime
or premature failure. 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 compartment 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, restrict-
ing blade and air movement and will probably show a lesser
quality of cut. 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 person-
nel. Consult your Big Dog®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. Big Dog®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 Big
Dog®Mowers for additional information.
Warranty
Warranty repair must be performed by a Big Dog®Mowers
Authorized Dealer before warranty credit can be allowed.