MTD 131-498A User manual

ASSEMBLY • OPERATION • MAINTENANCE • PARTS
38" LAWN TRACTOR
Important:
Read Safety Rules and
Instructions Carefully
Thank you for purchasing an
American built product.
Model Number
131-498A
PRINTED IN U.S.A.
FORM NO. 770-0863

I
INDEX
Safe Operation Practices.3
Assembly Instructions.4
Battery Information.5
Controls.8
Operation.10
Adjustments.12
Lubrication. 1 4
Maintenance .15
Off-Season Storage.19
Trouble Shooting Chart.20
Illustrated Parts for R.H. Side of Tractor.22
Parts List for R.H. Side of Tractor .23
Illustrated Parts for L.H. Side of Tractor.24
Parts List for L.H. Side of Tractor.25
Illustrated Parts for Frame View.26
Parts List for Frame View.27
Illustrated Parts for Deck View.28
Parts List for Deck View.29
Illustrated Parts forTransaxle.30
Parts List for Transaxle.31
Electrical Diagram.32
Deck Linkage.33
Parts Information..Back Cover
LIMITED WARRANTY
For one year from the date of original retail purchase, MTD PRODUCTS INC will either
repair or replace, at its option, free of charge, F.O.B. factory or authorized service firm,
any part or parts found to be defective in material or workmanship. Transportation charges
for any parts submitted for replacement under this warranty must be paid by the purchaser
unless such return is requested by MTD PRODUCTS INC.
This warranty will not apply to any part which has become inoperative due to misuse,
excessive use, accident, neglect, improper maintenance, alterations, or unless the unit
has been operated and maintained in accordance with the instructions furnished. This
warranty does not apply to the engine, motor, battery, battery charger or component parts
thereof. Please refer to the applicable manufacturer’s warranty on these items.
This warranty will not apply where the unit has been used commercially.
Warranty service is available through your local authorized service dealer or distributor. If
you do not know the dealer or distributor in your area, please write to the Customer Service
Department of MTD.
The return of a complete unit will not be accepted by the factory unless prior written
permission has been extended by MTD.
This warranty gives you specific legal rights. You may also have other rights which vary
from state to state.
TO PURCHASERS
OF INTERNAL COMBUSTION ENGINE EQUIPPED
MACHINERY OR DEVICES IN THE STATE OF CALIFORNIA
The equipment which you have just purchased does not have a spark arrester. If this equipment is used on
any forest covered land, brush covered land, or grass covered unimproved land in the State of California,
before using on such land, the California law requires that a spark arrester be provided. In addition, spark
arrester is required by law to be in effective working order. The spark arrester must be attached to the
exhaust system and comply with Section 4442 of the California Public Resources Code.
2

^ WARNING J
To reduce the potential for any injury, comply with the following safety instructions. Failure to comply with
the instructions may result in personal injury.
SAFE OPERATION PRACTICES FOR RIDING VEHICLES
1. It is suggested that this manual be read in its
entirety before attempting to assemble or
operate this unit. Keep this manual in a safe
place for future reference and for ordering
replacement parts.
2. This unit is a precision piece of power equip¬
ment, not a plaything. Therefore exercise ex¬
treme caution at all times.
3. Know the controls and how to stop quickly—
READ THIS OWNER’S MANUAL.
4. Do not allow children to operate vehicle. Do
not allow adults to operate it without proper
instruction. Only persons well acquainted
with these rules of safe operation should be
allowed to use your mower.
5. Do not carry passengers.
6. Keep the area of operation clear of all per¬
sons, particularly small children and pets.
Stop engine when they are in the vicinity of
your mower. Although the area of operation
should be completely cleared of foreign ob¬
jects, a small object may have been over¬
looked and could be accidently thrown by the
mower in any direction and cause injury.
7. Clear work area of objects which might be
picked up and thrown by the mower in any
direction and cause injury.
8. Stop the blade(s) when crossing gravel drives,
walks or roads.
9. Disengage all attachment clutches and shift
into neutral before attempting to start engine.
10. Disengage power to attachment(s) and stop
engine before leaving operating position.
11. Do not put hands or feet near or under rotating
parts. Keep clear of the discharge opening at
all times as the rotating blade(s) can cause in¬
jury. i
12. Disengage power to attachment(s) and stop
engine before making any repairs or ad¬
justments. Disconnect the spark plug wire
and keep the wire away from the plug to pre¬
vent accidental starting.
13. Before attempting to unclog the mower or
discharge chute, stop the engine. The mower
blade(s) may continue to rotate for a few
seconds after the engine is shut off.
Therefore, be sure the blade(s) have stopped
completely. Disconnect the spark plug wire
and keep the wire away from the plug to pre¬
vent accidental starting.
14. Disengage power to attachment(s) when
transporting or not in use.
15. Take all possible precautions when leaving
vehicle unattended such as disengaging
power-take-off, lowering attachments, shift¬
ing into neutral, setting parking brake, stop¬
ping engine and removing key.
16. Do not stop or start suddenly when going
uphill or downhill. Mow up and down face of
steep slopes; never across the face.
17. Reduce speed on slopes and in sharp turns to
prevent tipping or loss of control. Exercise ex¬
treme caution when changing direction on
slopes.
18. Stay alert for holes in terrain and other hidden
hazards.
19. Use care when pulling loads or using heavy
equipment.
A. Use only approved drawbar hitch points.
B. Limit loads to those you can safely control.
C. Do not turn sharply. Use care when back¬
ing.
D. Use counterweight(s) or wheel weights
when suggested in owner’s manual.
20. Watch out for traffic when crossing or near
roadways.
21. When using any attachments, neverdirect dis¬
charge of material toward bystanders nor
allow anyone near vehicle while in operation.
22. Handle gasoline with care. It is highly flam¬
mable.
A. Use approved gasoline container.
B. Never remove cap or add gasoline to a run¬
ning or hot engine or fill fuel tank indoors.
Wipe up spilled gasoline.
C. Open doors if engine is run in garage. Ex¬
haust fumes are dangerous. Do not run
engine indoors.
23. Keep the vehicle and attachments in good
operating condition, and keep safety devices
in place. Use guards as instructed in owner’s
manual.
24. Keep all nuts, bolts, and screws tight to be
sure the equipment is in safe working condi¬
tion.
25. Never store the equipment with gasoline in
the tank inside a building where fumes may
reach an open flame or spark. Allow engine to
cool before storing in any enclosure.
26. To reduce fire hazard, keep engine free of
grass, leaves or excessive grease.
27. The vehicle and attachments should be
stopped and inspected for damage after strik¬
ing a foreign object. The damage should be
repaired before restarting and operating the
equipment.
28. JDo not change the engine governor settings
or overspeed the engine.
29. When using the vehicle with mower, proceed
as follows:
(1) Mow only in daylight or in good artificial
light.
(2) Never make a cutting height adjustment
while engine is running if operator must
dismount to do so.
(3) Shut the engine off and wait until the
blade comes to a complete stop before
removing the grass catcher.
(4) Check blade mounting bolts for proper
tightness at frequent intervals.
30. Check grass catcher bags frequently for wear
or deterioration. For safety protection, replace
only with new bag meeting original equipment
specifications.
31. Look behind to make sure the area is clear
before placing the transmission in reverse
and continue looking behind while backing
up.

ASSEMBLY
FIGURE 1.
NOTE
This unit is shipped WITHOUT GAS¬
OLINE or OIL. After assembly, see
operating section of this manual for
proper fuel and engine oil recom¬
mendations.
-«—Contents of Hardware Pack:
(See figure 1)
A (2) Plastic Wing Nuts
B (1) Battery Hold Down
C (2) Ignition Keys
D (1) Steering Wheel Cap
E (1) Hex Lock Nut 5/16-24 Thread
F (1) Belleville Washer
G (1) Steering Tube
H (2) Battery Hold Down Rods
I (2) HexBoltsV4-20x.50"Lg.
J (2) Lock Washers V 4 " I.D.
K (2) Hex Nuts i/4-20Thread
Loose Parts in Carton:
L (1) Steering Wheel (Not Shown)
M (1) Battery Pack (Not Shown)
Reference to right hand or left hand
side of machine is from the driver’s
seat facing forward.
1. Place the steering tube (G) over the steering
shaft. See figure 2.
FIGURE 2.
Belleville
Steering/
Wheel (L)
FIGURE 3.
2. Place the steering wheel (H) over steering
— shaft and steering tube. See figure 3.
3. Secure steering wheel (L) with belleville
washer (F) (cup side down) and hex lock nut
(E). See figure 3. A Vz" wrench is required.
4

FIGURE 4. _
BATTERY INFORMATION
A.
{warning (
Battery acid must be handled with great care
as it will blister the skin and damage clothing.
It is advisable to wear goggles, rubber gloves,
and a protective apron when working with it.
B. I f for any reason acid should be spattered in
the eyes, wash it out immediately with clean
cold water. Seek medical aid if discomfort con¬
tinues.
C. If acid gets on clothes, dilute it with clean
water first, then neutralize with dilute ammonia
water or a water solution of baking soda.
D. Since battery acid is corrosive to metals, do
not pour into any sink or drain. Rinse empty
electrolyte containers and mutilate before
discarding.
<D
} DANGER {
BATTERIES CONTAIN SULFURIC
ACID AND MAY CONTAIN EXPLO¬
SIVE GASES (when electrolyte has
been added).
A. Keep sparks, flame, cigarettes away.
B. Hydrogen gas is generated during charging
and discharging.
C. Ventilate when charging or using in enclosed
space.
D. When using a charger—to avoid sparks,
NEVER connect or disconnect charger clips to
battery while charger is turned on.
E. Always shield eyes and protect skin and
clothing when working near batteries.
ACTIVATING THE BATTERY
NOTE
If your battery is activated (elec¬
trolyte in the battery) and installed
in the unit, go directly to step 9.
1. Place the battery to be filled on a workbench.
Never activate a battery in the unit.
2. Remove the fill caps from all cells.
3. Fill each cell carefully using 1.265 specific
gravity electrolyte. Fill each cell to the top of
the separators. Do not overfill.
4.
5.
Let the battery sit for 20 minutes to allow the
chemical reaction to take place.
Charge the battery at a MAXIMUM RATE OF 5
AMPS until the specific gravity reads 1.265.
Use a hydrometer to check the specific gravi¬
ty.
CAUTION
An excessive rate of charge will
damage the battery.
6. Check the level of electrolyte. Adjust level to
bottom of split ring if necessary with elec¬
trolyte.
7. Replace fill caps.
5

I
8. Once the battery has been activated, never
add anything except distilled water or a good
grade of drinking water.
9. If your battery has been installed in your unit
at the factory:
A. Use a hydrometer to check the specific
gravity. The specific gravity should be
1.265 at 80° F.
B. If it is less, remove the fill caps and use a
battery charger to bring the specific gravi¬
ty up to 1.265. NEVER CHARGE AT MORE
THAN 5 AMPS.
C. Replace the fill caps.
D. The positive cable has been attached to
the positive terminal of the battery at the
factory. You only have to attach the
negative cable (grounded) to the negative
(Neg, N or -) terminal of the battery with a
hex head bolt, lock washer and nut.
MAINTENANCE OF BATTERY
1. Check electrolyte level periodically (at least
every two weeks). Keep the level to the split
rings. Use only distilled water or a good quali¬
ty drinking water. Never add acid or any other
chemicals to the battery after initial activa¬
tion.
2. The battery should be checked with a
hydrometer after every 25 hours of operation.
If the specific gravity is less than 1.225, the
battery should be recharged. Maximum
charge rate 5 AMPS.
3. Coat the terminals and exposed wire with a
thin coat of grease or petroleum jelly for
longer service and protection against corro¬
sion.
4. The battery should be kept clean. Any
deposits of acid should be neutralized with
soda and water. Be careful not to get this solu¬
tion in the cells.
5. Avoid tipping the battery. Even a “sealed” bat¬
tery will leak electrolyte when tipped.
STORAGE OF THE BATTERY
1. S tore the battery in the unit.
2. K eep the exterior of the battery clean,
especially the top. A dirty battery will
discharge itself.
3.
Check the battery with a hydrometer. The bat¬
tery must be stored with a full charge. A
discharged battery will freeze.
Specific Gravity
1.265
1.250
1.200
1.150
1.100
Freezing Point
-71° F.
-62° F.
-16° F.
5° F.
16° F.
CAUTION
All batteries discharge
storage.
during
4. Recharge battery whenever the specific gravi¬
ty is less than 1.225, before returning to serv¬
ice or every two months, whichever comes
first.
COMMON CAUSES FOR BATTERY FAILURE
1. Overcharging
2. Undercharging
3. Lack of water
4. Loose hold downs and/or corroded connec¬
tions
5. Excessive loads
6. Battery electrolyte substitutes
7. Freezing of electrolyte
These failures do not constitute
warranty.
BATTERY REMOVAL OR INSTALLATION
®
} WARNING {
When removing the battery, follow
this order of disassembly to prevent
your wrench from shorting against
the frame.
1. Remove the Negative cable.
2. Remove the Positive cable.
To install a battery:
1. Attach the Positive cable.
2. Attach the Negative cable.
JUMP STARTING
1. Attach the first jumper cable from the Positive
terminal of the good battery to the Positive
terminal of the dead battery.
2. Attach the second jumper cable from the
Negative terminal of the good battery to the
FRAME OF THE UNIT WITH THE DEAD BAT¬
TERY.
®
\ WARNING \
Failure to use this starting pro¬
cedure could cause sparking, and
the gases in either battery could ex¬
plode.
6

INSTALL BATTERY
1. P l ace end of small red wire (with fuse holder)
— into rubber boot with positive ( + ) cable. See
figure 5.
FIGURE 5.
2. Place the battery into the lawn tractor, so that
the negative (-) terminal on battery is to the
—left hand side. See figure 6.
3. Place the end of rubber drain tube (on battery)
into the fixed convoluted tube on lawn tractor.
See figure 6. Reference to illustration on bot¬
tom of page 32 may also help.
FIGURE 6.
4. Place the battery hold down (B) over battery.
—See figure 7.
5. Secure battery hold down (B) with two hold
down rods (H) and plastic wing nuts (A). See
figure 7.
FIGURE 7.

6. Fasten the positive ( + ) cable and small red
wire (with fuse holder) to the positive ( + ) bat¬
tery terminal. Secure with hex bolt (I), lock
washer (J) and hex nut (K). See figure 8.
7. Fasten the negative (-) cable to the negative
(-) battery terminal. Secure with hex bolt (I),
lock washer (J) and hex nut (K). See figure 8.
NOTE
Be sure both cables are tightened
securely.
FIGURE 8.
Termini
8. S l i de the rubber boot on the positive (+) cable
down cable over positive ( + ) battery terminal.
See figure 9.
FIGURE 9.
CONTROLS
a. Throttle Control. The throttle control is used
to regulate the engine speed and choke the
engine. The engine should be operated from
3 A to full throttle when operating the cutting
deck or snow thrower (optional). See figure 10.
b. Gear Shift Lever. The gear shift lever is used
to shift into one of five Forward Gears,
“NEUTRAL” or “REVERSE.”
c. Lift and Disengagement Lever. It is used to
raise the cutting deck. Pulling it all the way
back and locking it disengages the blades.
The engine will not start unless the lift and
disengagement lever is in the disengaged
position. See figure 10.
FIGURE 10.
8

d. Ignition Switch. The ignition switch is located
on the left side of the dashboard. See figure
10. Turn the key to the “START” position to
start the engine. When the engine is running,
let the key return to the “ON” position. To
stop the engine, turn the key to the left to the
“OFF” position and remove it to prevent ac¬
cidental starting.
e. Light Switch. Push the light switch in to turn
on the lights. The lights will only operate
when the engine is running. See figure 10.
f. Brake Indicator Light. The brake indicator
light is located on the dash panel. The brake
light turns on when the operator depresses
the brake pedal while the ignition is on.
CAUTION
This light indicates that the brake is
engaged. Operating the unit with
the brake engaged will result in
rapid brake wear and premature
brake failure.
g. Ammeter. The c.nmeter registers the rate of
battery charge or discharge. The ammeter
should register on the plus side (approximate¬
ly 3 amps) when the engine is running. With
the engine idling, the charging rate will be
less. See figure 10.
The headlights operate directly from the alter¬
nator and will not register on the ammeter.
h. Brake. The brake pedal is located on the right
hand side of the mower and is operated by
depressing it with your right foot. See figure
11 .
i. Brake Lock. The brake lock is located on the
right hand side of the mower. To lock the
brake, depress the brake pedal and lift up the
lock button. The pedal will stay depressed. To
release, depress the pedal. See figure 12.
FIGURE 12.
j. Clutch Pedal. The clutch pedal is used to
disengage the drive mechanism. Depressing
the clutch pedal at any time will reduce
mower speed. See figure 13.
FIGURE 13.
k.
Clutch Lockout. When the clutch pedal is
depressed all the way, it can be locked by
placing the clutch lockout in the “START”
position as shown in figure 14. The clutch
lockout must be in this position before the
engine will start.
NOTE
The engine will not start unless
the clutch lockout is in the
“START” position and the lift
lever is in the DISENGAGED posi¬
tion.
FIGURE 11.

FIGURE 14.
I. Cutting Controls. The cutting controls consist
of the height of cut stop and the wheel height
adjusters.
Height of Cut Stop. See figure 15. Lift the stop
and set it at the desired cutting height.
FIGURE 15.
Wheel Height Adjuster. See figure 16. Move the
lever towards the wheel and set it in the desired
cutting height.
FIGURE 16.
The cutting height of the mower can be set in two
different ways: FULL FLOAT position where the
deck follows the contour of the ground, and the
SUSPENDED position where the deck hangs from
the frame of the rider. The suspended position is
normally used for cutting rough uneven ground.
To set the cutting deck in the full float position,
set the wheel height adjusters in the desired cut¬
ting height as indicated in figure 15. Set height of
cut stop all the way forward. See figure 15.
To set the cutting deck in the suspended position,
set the height of cut stop in the desired cutting
height and then set the deck wheels so they just
clear the ground.
OPERATION
A
CAUTION
Keep all shields in place.
Before leaving operator’s position:
a. Shift transmission to neutral
b. Set parking brake
c. Disengage attachment clutch
d. Shut off engine
e. Remove ignition key
Wait for all movement to stop before
servicing machine.
Keep people and pets a safe distance
away from machine.
Look to the rear before backing up.
A
TIRE PRESSURE
FOR SHIPPING PURPOSES, THE TIRES ON YOUR
UNIT MAY BE OVER INFLATED. TIRE PRESSURE
SHOULD BE REDUCED BEFORE UNIT IS PUT IN¬
TO OPERATION. PRESSURE SHOULD BE AP¬
PROXIMATELY 15 P.S.I. EQUAL TIRE PRESSURE
SHOULD BE MAINTAINED ON ALL TIRES. MAX¬
IMUM TIRE PRESSURE IS 30 P.S.I.
CAUTION
Installation of tire to rim:
1. Lubricate tire beads and rim
flanges.
2. Do not exceed 30 P.S.I. when
seating beads.
3. Adjust to recommended pres¬
sure after beads are sealed.
10