Yard-Man 31AE993I401 User Manual

OPERATOR’S MANUAL

33” Snow Thrower

Model 31AE993I401

IMPORTANT: READ SAFETY RULES AND INSTR UCTIONS CAREFULLY

Warning: This unit is equipped with an internal combustion engine and should not be used on or near any unimproved forest-

covered, brush-covered or grass-covered land unless the engine’s exhaust system is equipped with a spark arrester meeting
applicable local or state laws (if any). If a spark arrester is used, it should be maintained in effective working order by the operator.
In the State of California the above is required by law (Section 4442 of the California Public Resources Code). Other states may have
similar laws. Federal laws apply on federal lands. A spark arrester for the muffler is available through your nearest engine authorized
service dealer or contact the service department, P.O. Box 368022 Cleveland, Ohio 44136-9722.

MTD PRODUCTS INC. P.O. BOX 368022 CLEVELAND, OHIO 44136-9722

PRINTED IN U.S.A.

FORM NO.

770-10278B.fm
(5/2001)

TABLE OF CONTENTS

Content Page

Important Safe Operation Practices...................................................................3

Assembling Your Snow Thrower .......................................................................5

Knowing Your Snow Thrower ............................................................................7

Operating Your Snow Thrower ..........................................................................9

Making Adjustments ..........................................................................................10

Maintaining Your Snow Thrower........................................................................12

Servicing Your Snow Thrower ...........................................................................13

Off-Season Storage...........................................................................................17

Trouble Shooting Guide.....................................................................................18

Parts List............................................................................................................19

FINDING MODEL NUMBER

This Operator’s Manual is an important part of your new snow thrower. It will help you assemble, prepare
and maintain the unit for best performance. Please read and understand what it says.

Before you star t to prepa re yo ur sno w thr ower for its first use, please locate the model
plate and copy the information from it in this Operator’s Manual. The information on the
model plate is very important if you need help from your dealer or the Customer Support
Department.

You can locate the model number by looking at the lower frame cover on the rear of your snow thrower. A
sample model plate is explained below. For future reference, please copy the model number and the serial
number of the equipment in the space below.

(Model Number)

CLEVELAND, OHIO 44136

(Serial Number)

MTD PRODUCTS INC

Copy the model number here:

Copy the serial number here:

CALLING CUSTOMER SUPPORT

If you have difficulty assembling this product or have any questions regarding the controls, operation or
maintenance of this unit, please call the Customer Support Department.

Call 1- (330) 220-4MTD (4683) or 1- (800)-800-7310 to reach a Customer Support
representative. Please have your unit’s model number and serial number ready when you
call. See previous section to locate this information. You will be asked to enter the serial
number in order to process your call.

For more details about your unit, visit our website at www.yardman.com

2

SECTION 1: IMPORTANT SAFE OPERATION PRACTICES

This symbol points out important safety instructions which, if not followed, could endanger the personal
safety and/or property of yourself and others. Read and follow all instructions in this manual before
attempting to operate this machine. Failure to comply with these instructions may result in personal
injury. When you see this symbol—heed its warning.

WARNING: Engine Exhaust, some of its constituents, and certain vehicle components contain or emit

chemicals known to State of California to cause cancer and birth defects or other reproductive harm.

DANGER: This machine was built to be operated according to the rules for safe operation in this

manual. As with any type of power equipment, carelessness or error on the part of the operator can
result in serious injury. This machine is capable of amputating hands and feet and throwing objects.
Failure to observe the following safety instructions could result in serious injury or death.

Training

1. Read, understand, a nd follow all in struction s on the
machine and in the manual(s ) before a ttempting to
assemble and o perate. Keep this ma nual in a safe pl ace
for future and regular re ference a nd for orde ring
replacement parts.

2. Be familiar with all controls and their prope r operation.
Know how to stop the mach ine and d isengage them
quickly.

3. Never allow childre n under 14 y ears old to operate this
machine. Children 14 years old and over should rea d and
understand the op eration in struction s and sa fety rules i n
this manual and should be trained and sup ervised b y a
parent.

4. Never allow adults to operate this machine without
proper instruction.

5. Thrown objects can cause seriou s personal injury . Plan
your snow throwin g pattern to avoid di scharge of mat erial
toward roads, bystanders and the like.

6. Keep bystanders, hel pers, pets and chi ldren at l east 75
feet from the machin e while it is in operatio n. Stop
machine if anyo ne enters the area.

7. Exercise caution to avoid s lipping o r falli ng, espe cially
when operating in reverse.

Preparation

1. Thoroughly inspect the area wh ere the eq uipment i s to
be used. Remove all door mat s, newspa pers, sle ds,
boards, wires and o ther foreig n object s which c ould be
tripped over or throw n by the auger/imp eller.

2. Always wear safet y glasses or eye s hields d uring
operation and while performing an adjustment or repair to
protect your eyes. T hrown ob jects whi ch ricochet can
cause serious inj ury to the eyes.

3. Do not operate wit hout wearing adequate winter outer
garments. Do not wear jewelry, long scarves or other
loose clothing which cou ld becom e entang led in m oving
parts. Wear footwear w hich wi ll improve footing on
slippery surfaces.

4. Use a grounded three wire ex tension cord and receptac le
for all units with electric start engi nes.

5. Adjust collector housing height to clear gravel or crushed
rock surfaces.

6. Disengage all cl utch levers before st arting the engin e.

7. Never attempt to m ake any adjustme nts while engine i s
running, except where spec ifically recomm ended in the
operator’s manual.

8. Let engine and m achine adju st to outd oor tem perature
before starting to clear snow.

9. To avoid personal injury or pro perty damage use extre me
care in handling gasolin e. Gasol ine is e xtremely
flammable and the v apors are explosiv e. Serious
personal injury c an occur w hen gas oline is spilled o n
yourself or your c lothes which c an ignit e. Wash y our skin
and change clot hes immedi ately.

a. Use only an approved gasoline container.
b. Extinguish all cigarettes, cig ars, pipes and other

sources of ignition.
c. Never fuel machine indoo rs.
d. Never remove gas cap or add fue l whil e the

engine is hot or running.
e. Allow engine to cool at leas t two minu tes before

refueling.
f. Never over fill fuel tank. Fil l tank to no more tha n

½ inch below bottom of fill er neck to provide space

for fuel expansi on.
g. Replace gasoli ne cap an d tighten secu rely.
h. If gasoline is sp illed, wip e it off th e engine and

equipment. Move machine to another area . Wait 5

minutes before start ing the e ngine.
i. Never store the machine or fuel containe r inside

where there is an o pen flam e, spark or pilot l ight

(e.g. furnace, water heater, space heate r, clothes

dryer etc.).
j. Allow machine to cool 5 minute s before storin g.

Operation

1. Do not put hands o r feet near rotating p arts, in the a uger/
impeller housing o r disc harge chu te. Cont act wit h the
rotating parts can am putate ha nds and feet.

2. The auger/impelle r clutch lev er is a safety de vice. Nev er
bypass its operati on. Doing so, makes the ma chine
unsafe and may cause p ersonal i njury.

3. The clutch leve rs must o perate easily in both d irections
and automatical ly return to the disengaged pos ition when
released.

4. Never operate with a miss ing or da maged di scharge
chute. Keep all safe ty devic es in pl ace and working.

3

5. Never run an engine indoors or in a poorly vent ilated
area. Engine exhaust contains carbon monoxide , an
odorless and dea dly gas .

6. Do not operate mac hine while under the influenc e of
alcohol or drugs.

7. Muffler and engine be come hot and c an cause a burn. D o
not touch.

8. Exercise extreme ca ution when operating on or cro ssing
gravel surfaces. Stay alert for hidden hazards or traffic.

9. Exercise caution w hen changi ng directi on and w hile
operating on slop es.

10. Plan your snow t hrowing pat tern to av oid disc harge
towards windows, wa lls, cars e tc. To avoid prope rty
damage or personal injury caus ed by a ricochet.

11. Never direct disc harge at c hildren, b ystander s and pet s
or allow anyone in front of t he machi ne.

12. Do not overload machine capa city by attemptin g to clear
snow at too fast of a rate.

13. Never operate this machin e without good visib ility or light.
Always be sure of your footi ng and k eep a firm hold on
the handles. Walk, n ever run.

14. Disengage power to t he aug er/impeller w hen
transporting or not in use.

15. Never operate mach ine at hi gh transp ort speeds on
slippery surfaces. Look down and b ehind an d use ca re
when in reverse.

16. If the machine shoul d start to vibrate abn ormally, stop the
engine, disconnect the spark plug an d grou nd it agai nst
the engine. Inspect thoroughly for dam age. Repair any
damage before starting and ope rating.

17. Disengage all cl utch lev ers and st op engin e before y ou
leave the operating position (be hind the handles). Wai t
until the auger/im peller come s to a complete stop befo re
unclogging the d ischarge chute, m aking an y
adjustments, or inspecti ons.

18. Never put your hand in the d ischarge or colle ctor
openings. Always use a cl earing to ol to unc log the
discharge opening.

19. Use only attach ments a nd acce ssories approved by the
manufacturer (e.g. wheel weigh ts, tire c hains, cabs etc.) .

20. If situations occur which are not covered in this manua l,
use care and good judgment. Cont act your dealer or
telephone [phone] for assistance and the name
of your nearest s ervicing dealer.

Maintenance And Storage

1. Never tamper with safety devices. Check their proper
operation regularly.

2. Disengage all cl utch lev ers and stop engi ne. Wait u ntil
the auger/impelle r come to a complet e stop. D isconn ect
the spark plug wi re and grou nd again st the en gine to
prevent unintended starting before cl eaning, repairi ng, or
inspecting.

3. Check bolts, and sc rews for pro per tig htness at frequent
intervals to keep t he ma chine in safe worki ng condi tion.
Also, visually inspe ct mach ine for an y damag e.

4. Do not change the engi ne governor settin g or over-speed
the engine. The g overnor c ontrols the m aximum s afe
operating speed o f the eng ine.

5. Snow thrower shave plates an d skid shoes are subj ect to
wear and damage. F or your s afety protecti on, freque ntly
check all compon ents and replace with origin al
equipment manufac turer’s (O.E.M.) pa rts only. Use of
parts which do not m eet the ori ginal eq uipment
specifications may lea d to imp roper perfor mance an d
compromise safety.

6. Check clutch co ntrols period ically to verify they engage
and disengage prope rly and adjust, if ne cessary. Refer to
the adjustment s ection i n this op erator’s manual for
instructions.

7. Maintain or replace safety and instruction labels, as
necessary.

8. Observe proper disposal l aws and regulations for ga s, oil,
etc. to protect the environmen t.

9. Prior to storing, run machine a few minutes to clear snow
from machine an d prevent freeze up of auger/i mpeller.

10. Never store the machine or fuel c ontainer i nside whe re
there is an open flame, spark or pilot light such as a wate r
heater, furnace ,cloth es dryer etc .

11. Always refer to the operator’s ma nual for p roper
instructions on off-season storage.

WARNING: Restrict the use of this

power machine to persons who read,
understand and follow the warnings and
instructions in this manual and on the
machine.

4

SECTION 2: ASSEMBLING YOUR SNOW THROWER

NOTE: Any reference in this manual to the left or right

side of the snow thrower is observed from the
operator’s position.

Upper Handle

Unpacking

• Remove staples from the top, sides, and ends of
the shipping crate.

• Set panels aside to avoid tire punctures or personal
injury.

• Remove and discard plastic bag that covers unit.

• Roll the unit out of the crate.

• Check the crat e thorough ly for loos e parts bef ore

discarding.

Loose Parts

• The augers are secured to the auger shaft with two
shear bolts and hex lock nuts. If you hit a foreign
object or ice jam, the snow thrower is designed so
that the bolts may shear. Two replacement shear
bolts and nuts are provided for your convenience.
Store in a safe place until needed. See Figure 1.

Shear Bolts

Figure 1

Hex Lock
Nuts

Steering Cable

Tighten these

Wing Nuts

Lower Handle

Cable Tie

Upper Shift Rod

Clutch Rod

Connector

Carriage Bolt

Cupped Wa she r

Wing Nut

Upper Shift Rod

Figure 2

• Raise the upper handle assembly until it locks over
the lower handle. See Figure 3.

• Look at the lower rear of the snow thrower frame to
be sure all the cables are aligned with the cable
roller guides.

IMPORT ANT :

standard hex bolts. Any damage to the auger gearbox
or other components from standard hex bolts will not be
covered by your snow thrower’s warranty.

NEVER replace the auger shear bolts with

Assembling Handle

WARNING: Disconnect the spark plug

wire and ground it against the engine to
prevent unintended starting.

IMPORT ANT :

later on in this section, before operating your snow
thrower. Failure to follow these instructions may cause
damage to the snow thrower.

• Remove the lower plastic wing nut, cupped washer
and carriage bolt from each side of the lower
handle. See Figure 2.

Make any final adjustments, as instructed

Handle Panel

Wing Nuts

Upper Handle

Lower Handle

Figure 3

• Secure the upper handle and lower handle with the
two plastic wing nuts, cupped washers and carriage
bolts previously removed. Attach these hardware
on the lower hole in the handles.

• Tighten the two wing nu ts alre ady in plac e on the
upper holes and secure the handles firmly.Slide the
shift rod connector down over the end of the lower

5

shift rod. Tap the connector until it locks over the
lower shift rod. See Figure 2.

NOTE: If the connector is not properly assembled, the

shift rod will pivot and y ou will not be able to change
speeds or change directions.

• Remove the hairpin clip from the upper chute crank
and slide the upper chute crank through the upper
chute crank bracket and into the lower chute crank.
Align the two holes on both chute cranks and insert
the hairpin clip removed earlier, through these
holes. See Figure 4.

Upper Chute Crank

Upper Chute

Crank Bracket

Hairpin Clip

Lower Chute C rank

Figure 4

• If not already attached, slip the cables that run from
the handle panel to the discharge chute into the
cable guide located on top of the engine as shown
in Figure 5.

Discharge Chute

Cable Guide

Figure 5

• Unwrap the headlight wire which is attached to the
headlight, beneath the handle panel. Wind the
headlight wire around the lower right handle until
excess slack is removed. See Figure 6.

• Plug the wire from the headlight into the alternator
lead coming from the right side of the engine
underneath the fuel tank.

Alternator Lead

Alternator
Lead

Lamp Wire

(Wheels left out for clarity)

Figure 6

Final Adjustments

NOTE: It may be helpful t o read Section 3, Knowing
Your Snow Thrower, to help identify certain areas of the
snow thrower before performing adjustments.

Traction Control and Shift Lever

To check the adjustment of the traction control and shift
lever, proceed as follows:

• Move the shift lever into sixth (6) position.

• With the traction control released, push the snow

thrower forward, then pull it back. The machine
should move freely.

• Engage the traction control and attempt to move
the machine both forward and back, resistance
should be felt.

• Move the shift lever in to the f ast revers e (R2)
position and repeat the previous two steps.

If you experienced resistance rolling the unit, either
when repositioning the shift lever from 6 to R2 or when
attempting to move the machine with the traction
control released, adjust the traction control
immediately. To adjust, proceed as follows:

• Loosen the jam nut on the traction control cable
and UNTHREAD the cable one full turn.

• Recheck adjustment.

• Retighten the jam nut to secure the cable when

correct adjustment is reached.

NOTE: For more details, refer to Traction Control
Adjustment

Auger Control

Check the adjustment of the auger control as follows:

• Push down on the auger c ontro l unt il th e smal l
rubber bumper contacts the upper handle. There
should be a small amount of slack in the auger
control cable.

• Release the auger cont rol. The ca ble shoul d be
straight. Make certain you can depress the auger
control against the left handle completely.

If adjustment is necessary, proceed as follows:

6

• Loosen the jam nut and thread the cable in (for less
slack) or out (for more slack) as necessary. See
Figure 7.

• Recheck adjustment; readjust as necessary and
tighten the jam nut.

“Z” End

Jam Nut

NOTE: Make certain the en tire bottom surface of skid

shoe is against the ground to avoid uneven wear on the
skid shoes.

High

Shave Plate

Low

Auger Control

Cable

Figure 7

Carriage Bolts

Skid

Shoes

Skid Shoes

The space between the shave plate and the ground can
be adjusted by repositioning the skid shoes. For close
snow removal, as when using on a smooth concrete or
asphalt driveway, place the skid shoes in the low
position. Use the middle or high position when the area
to be cleared is uneven. When operating on gravel,
always put skid shoes in the high position.
See Figure 8.

Adjust skid shoes as follows:

• Loosen, but do not remove, the three hex nuts
which fasten the skid shoe to the auger housing.

• Raise or lower the skid shoe to desired position.

• Retighten the hex nuts loosened earlier.

• Repeat on the other side of the snow thrower.

Tire Pressure (Pneumatic Tires)

The tires are overinflated for shipping purposes.

• Check tire pressure. Maintain pressure between 10
and 14 psi.

NOTE: If the tire pressure is not equal in both tires, the
unit may pull to one side or the other.

WARNING: Maximum tire pressure

under any circumstance is 30 psi. Equal
tire pressure should be maintained at all
times. Excessive pressure (over 30 psi)
when seating beads may cause tire/rim
assembly to burst with force sufficient to
cause serious injury.

SECTION 3: KNOWING YOUR SNOW THROWER

simultaneously with the traction control, the operator

WARNING: Read, understand, and

follow all instructions and warnings on
the machine and in this manual before
operating.

Traction Control / Auger Cont rol Lock

The traction control is located on the right handle.
Squeeze the traction control to engage the wheel drive.
Release to stop. See Figure 9.

This same lever also locks the auger control so you can
operate the chute crank without interrupting the snow
throwing process. If the auger control is engaged

can release the auger control (on the left handle) and
the augers will remain engaged. Release the traction
control to stop the augers and wheel drive (the auger
control must also be released).

IMPORT ANT :

changing speeds.

Auger Control

The auger control is located on the left handle.
Squeeze the auger control to engage the augers.
Release to stop the snow throwing action. The traction
control must also be released in order to stop the auger.

Hex Nuts

Figure 8

Always release the traction control before

7

Shift Lever

The shift lever is located in the center of the handle
panel and is used to determine ground speed and
direction of travel. It can be moved into any of eight
positions. See Figure 9.

IMPORT ANT :

changing speeds.

Always release traction the control before

Forward

Your snow thrower has six forward (F) speeds. Position
number one (1) is the slowest and position number six
(6) is the fastest.

Reverse

Your snow thrower has two reverse (R) s peeds. R1 is
the slower, while R2 is the faster of the two.

Chute Crank

The chute crank is located on the left hand side of the
snow thrower. To change the direction in which snow is
thrown, turn the chute crank as follows:

• Turn clockwise to discharge to the left;

• Turn counterclockwise to discharge to the right.

• Operate the snow thrower in open areas until
becoming familiar with these controls.

Chute Tilt Contro l

The distance snow is thrown can be changed by
adjusting the angle of the chute assembly. Move the
chute tilt control forward to decrease the distance,
toward the rear to increase. See Figure 9.

Discharge Chut e

The angle of the discharge chute controls the distance
that the snow is thrown. Tilt the discharge chute up for
greater distance; tilt down for less distance.

Skid Shoe

The position of the skid shoe is determined by the
condition of the ground from where snow has to be
removed.

Headlight

The headlight is on whenever the engine is running.

Wheel Steering Controls

The left and right wheel steering controls are located on
the underside of the handles and are used to assist in
steering the snow thrower.

• Squeeze the right wheel steering control when
turning right; squeeze the left control when turning
left.

T raction Contro l /
Auger Control Lock

Headlight

Fuel Tank

Discharge
Chute

Throttle Control

The throttle control is located on the engine. It regulates
the speed of the engine. See Figure 9.

Safety Ignition Key

The safety ignition key must be fully inserted in the
switch before the unit will start. Remove key when snow
thrower is not in use. Do not attempt to turn the key.
See Figure 9.

Shift Lever

Auger Drive Control

Chute Tilt
Control

Chute Crank

Wheel St eer in g
Control

Primer

Choke

Electric
Starter
Button

Switch
Box

Auger

Skid Shoe

Figure 9

8

Safety
Ignition Key

Throttle
Control

Recoil
Starter
Handle

SECTION 4: OPERATING YOUR SNOW THROWER

Before Starting

WARNING: Read, understand, and

follow all instructions and warnings on
the machine and in this manual before
operating.

Gas And Oil Fill-up

Service the engine with gasoline and oil as
instructed in the separate engine manual packed with
your snow thrower. Read instructions carefully.

WARNING: Use extreme care when

handling gasoline. Gasoline is extremely
flammable and the vapors are explosive.
Never fuel machine indoors or while the
engine is hot or running. Extinguish
cigarettes, cigars, pip es an o th er s our ces
of ignition.

• A plastic cap is provided inside the fuel fill opening
on the fuel tank. Remove and discard this cap
before filling up the tank. Use the separate fuel tank
cap to close after fill-up.

To Start Engine

NOTE: If unit shows any sign of motion (drive or

augers) with the clutch g rips disengaged, shut engine
off immediately. Readjust as instructed in the Final
Adjustments in the Assembly Section.

• Attach spark plug wire to spark plug. Make certain
the metal loop on end of the spark plug wire (inside
the boot) is fastened securely over the metal tip on
the spark plug.

• Make certain the auger and drive clutch levers are
in the disengaged (released) position.

• Move throttle control up to FAST position. Insert
ignition key into slot. See Figure 9. Be certain it
snaps into place. Do not turn key.

NOTE: Engine will not start unless ignition key is

inserted i nto ig nitio n slot in carb uretor cover .

Electric Starter

• Determine that your house wiring is a three-wire
grounded system. Ask a licensed electrician if you
are not certain.

WARNING: The electric starter is

equipped with a grounded three-wire
power cord and plug and is designed to
operate on 120 volt AC household
current. It must be used with a properly
grounded three-prong receptacle at all
times to avoid the possibility of electric
shock. Follow all instructions carefully
prior to operating the electric starter.

• If your house wiring system is not a three-wire
grounded system, do not use this electric starter
under any condi tions.

• If your home electrical system is grounded, but a
three-hole receptacle is not available, one should
be installed by a licensed electrician before using
the electr ic start er.

• If you have a grounded three-prong receptacle,
proceed as follows:

• Rotate choke knob to OFF position and do not
prime engine.

• Connect power cord to switch box on engine. Plug
the other end of power cord into a three-hole,
grounded 120 volt AC receptacle.

• Push starter button on top of the engine to crank
engine. As you crank the engine, move choke knob
to FULL choke position.

• When engine starts, release starter button, and
move choke gradually to OFF. If engine falters,
move choke immediately to FULL and then
gradually to OFF.

• When disconnecting the power cord, always unplug
from the three-prong receptacle first and then from
the snow thrower.

Recoil Starter

• Rotate choke knob to FULL choke position (cold
engine start). If engine is warm, place choke in OFF
position instead of FULL.

• Push primer button two or three times. If engine is
warm, pus h prim er but ton on ce on ly.

NOTE: Always cover v ent hol e in pr i mer bu tton when

pushing. Additional priming may be n ecessary for fir st
start if temp eratur e is below 15 °F.

• Grasp starter handle and pull rope out slowly, until
it pulls slightly harder. Let rope rewind slowly.

• Pull starter handle rapidly. Do not allow handle to
snap back. Allow it to rewind slowly while keeping a
firm hold on the starter handle.

• Repeat the previous steps until engine starts.

9