IMPORT ANT: Read safety rules and instructions carefull y befor e operating equipment.
21” Rear & Side Discharge
Mulching Lawn Mower
Model 437
PRINTED IN U.S.A.
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 eng ine’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 t he State of California t he above is required
by law (Section 4442 of the California Public Resources Code). Other states may h ave similar laws. Federal laws apply on federal lands. A spark
arrester for the muffler is available through your nearest engine au thorized service dealer or contact the service department, P.O. Box 361 131
Cleveland, Ohio 44136-0019.
MTD LLC, P .O . BOX 361131 CLEVELAND, OHIO 44136-0019
Operator’ s Manual
FORM NO.
769-00668.fm
(1/2003)
2
TABLE OF CONTENTS
Content Page
Important Safe Ope ration Practices ....................................... ............................... 3
Slope Gauge ............................................................. ............................................ 6
Assembling Your Lawn Mower .................................. ....................................... ..... 7
Know Your Lawn Mower ...................................... ...................................... ............ 9
Operating Your Lawn Mower ..................................................................... .......... 10
Maintaining Your Lawn Mow er ............................................... ............................. 12
Service ............................................ ....................................... ............................. 13
Making Adjustments ........................................................ .................................... 14
Off- Season Stora ge.................. ............................................. ............................. 15
Troubleshooting ........................................................ ....................................... ... 15
Parts List ............... ....................................... ............................................. .......... 16
FINDING MODEL NUMBER
This Operator’s M anual is an impo rtant part of your new Lawn Mower. It will help you ass emble, prepare and
maintain the unit for best perfor mance. Please read and under stand what it says.
Before you start assembling your new equipme nt, please locate the model plate on the
equipment and copy the info rmation from it in the space prov ided below. The information on the
model plate is very impor tant if you need help from our Cust omer Support Department or an
authorized dealer.
• You can locate the model nu mber by standing behind the unit in the operating position and loo king down at
the rear of the deck. A samp le model plate is explained bel ow. For future reference, plea se copy the model
number and the serial numbe r of the equipment in the space below .
ENGINE INFORMATION
The engine manufacturer is responsible for all engine-related issues with regards to performan ce, power-rating,
specifications, warra nty and service. Please refer to th e engine manufacturer’s O wner’s/Operator’s Manual packed
separately with your un it for more information.
CALLING CUSTOME R SU PPORT
If you have difficulty ass embling this product or hav e any questions regardin g the controls, operatio n or
maintenance of this unit, pl ease call the Customer Support Dep artment.
Call 1- (330) 220-4MTD (4683) or 1- (800)-800-7310 to reach a Custome r Support representa tive.
Please have your unit’ s model number and serial nu mber ready when you call. See previous section
to locate this informatio n. You will be asked to enter the serial number in order to proces s your call.
Copy the model number here:
Copy the serial number here:
( M o del Num ber )
( S er i a l Numb er )
www.y ardman.com
MTD LLC
P . O. BOX
361131
CLEVELAND,OH
44136
330-220-4683
800-800-7310
For more details about your unit, visit our website at www.yar dman.com
3
SECTION 1: IMPORTANT SAFE OPERATION PRACTICES
General Operation
1. Read this operator’ s manua l carefully in its entiret y
before attempting to assemble this machine. Read ,
understand, and follow all instructions on the
machine and in the manua l(s) before operation. Be
completely famili ar with the contr ols and the proper
use of this machine bef ore operating it. Keep this
manual in a safe place fo r future and regular
reference and for ordering r eplacement parts.
2. This machine is a pre cision piece of power
equipment, not a plaything. Therefore, exercise
extreme caution at al l times. Your unit has been
designed to perform one job: to mo w grass. Do not
use it for any other purpo se.
3. Never allow children unde r 14 years old to operate
this machine. Children 14 y ears old and over
should read and understand the operation
instructions and safety rules in this manual an d
should be trained and supervi sed by a parent. Only
responsible individ uals who are familiar with thes e
safe operation rules shou ld use this machine.
4. Thoroughly inspect the area where the equipment
is to be used. Remove all sto nes, sticks, wire,
bones, toys and other foreig n objects which could
be tripped over or picked up and thrown by the
blade. Thrown obje cts can cause se rious person al
injury. Plan yo ur mowing pattern to avoid discharge
of material toward roads , sidewalks, bystanders
and the like. Also, avoid disch arging material
against a wall or obstruc tion which may cause
discharged material to ricoc het toward operator.
5. To help avoid blade contac t or a thrown object
injury, stay in the op erator zone behind the handles
and keep bystander s, helpers, children and pe ts at
least 75 feet from the mach ine while it is in
operation. Stop machin e if anyone enters the area.
6. Always wear safety gla sses or safety goggles
during operation and while pe rforming an
adjustment or re pair to protect yo ur eyes. Thrown
objects which rico chet can cause se rious injury to
the eyes.
7. Wear sturdy, rough- soled work shoes and clos e-
fitting slacks and shi rts. Shirts and pants that cover
the arms and legs and steel -toed shoes are
recommended. Never op erate this machine in bare
feet, sandals, slipp ery or light weight (e.g. canvas )
shoes.
8. Do not put hands or feet near rotatin g parts or
under the cutting deck. Contac t with the blade can
amputate hands and feet.
9. A missing or damaged di scharge cover can cause
blade contact or thrown objec t injuries.
10. Many injuries occur as a re sult of the mower being
pulled over the foot durin g a fall caused by slipping
or tripping. Do not hold on to the mower if you are
falling; release the handle immediately.
11. Never pull the mower back towa rd you while you
are walking. If you must bac k the mower away from
a wall or obstruction first look do wn and behind to
avoid tripping and then follo w these steps:
a. Step back from the mower to full y extend
your arms.
b. Be sure you are well balanced with sure
footing.
c. Pul l the mower back slowly, no more tha n
half way toward you.
d. Repeat these steps as need ed.
5. Do not operate the mower while unde r the influence
of alcohol or drugs.
6. Do not engage the self-prop elled mechanism on
units so equipped while s tarting engine.
7. The blade control handl e is a safety device. Neve r
attempt to bypass its op eration. Doing so makes
the safety dev ice inoperative and may result in
personal injury throu gh contact with the rotating
blade. The blade contro l handle must operate
easily in both directi ons and automatically r eturn to
the disengaged position when releas ed.
WARNING:
This symbol points out i mportant safety instructions which, if not followed, could endanger
the personal safe ty and/or property o f yourself and other s. Read and follow all instructions i n this manual
before attempting to operate this machine. Failure to compl y with these instructions may result in personal
injury. When you se e this symbol— HEED ITS WARNING
WARNING:
This machine was built to be operated according to the rules for safe operation in this
manual. As with any type of power equ ipment, carelessness or er ror on the part of the operator can result in
serious injury. This machine is capable of amputati ng hands and feet and throwing ob jects. Failure to
observe the following safety instructions could result in serious injury or dea th.
WARNING:
Engine exhaust, some of its constituents, and cer tain vehicle components contain or
emit chemicals known to Stat e of Califor nia to cause ca ncer and birth defects or other
reproductive harm.
4
8. Never operate the mower in w et grass. Always be
sure of your footing. A sl ip and fall can cause
serious personal inju ry. If you feel you are losing
your footing, release the blade control handle
immediately and the bl ade will stop rotating within
three seconds.
9. Mow in daylight or good artificial light. Walk, never
run. Stop the blade when cros sing gravel drives,
walkways or roads.
10. If the equipment should start to v ibrate abnormally,
stop the engine and check i mmediately for the
cause. Vibration is general ly a warning of trouble.
11. Shut the engine off and wait until the blade comes
to a complete stop before re moving the grass
catcher or uncloggi ng the chute. The cutting blade
continues to rotate for a few sec onds after the
engine is shut off. Never pl ace any part of the body
in the blade area until you are s ure the blade has
stopped rotating.
12. Never operate mower without prop er trail shield,
discharge cove r, grass catcher, blade c ontrol
handle or other safety prote ctive devices in place
and working. Never operate mower with damaged
safety de vices. Failur e t o do s o, can resu lt in
personal injury.
13. Muffler and engine becom e hot and can cause a
burn. Do not touch.
14. Only use parts and accessories made for this
machine by the original equipment manufacturer
(O.E.M). Failure to do so can ca use personal injur y.
15. If situations occur which are not covered in this
manual, use care and goo d judgment. Contact your
dealer for assistance. Telephone 1-800-800-73 10
for the name of your nearest dealer .
Slope Operation
Slopes are a major facto r related to slip and fall
accidents which can r esult in severe injur y. Operation
on slopes require s extra caution. If you f eel uneasy on a
slope, do not mow it. Before o perating this unit on a
slope or hilly a rea, use the slope gauge on page 6 to
measure slopes. If the slope is greater than 15 degrees,
do not mow it.
Do:
1. Mow across the face of slopes; never up and d own.
Exercise extreme cautio n when changing directio n
on slopes.
2. Watch for holes, ruts, rock s, hidden objects, or
bumps which can cause you to slip or trip. Tall
grass can hide obst acles.
3. Always be sure of your footing. A slip and fall can
cause serious person al injury. If you feel you are
losing your ba lance, release th e blade control
handle immediately, and the bla de will stop rotating
within 3 second s.
Do Not:
1. Do not mow near drop-offs, ditches or
embankments, you co uld lose your footing or
balance.
2. Do not mow slopes greater than 15 de grees as
shown on the slope gauge.
3. Do not mow on wet grass. Unstabl e footing could
cause slipping.
Children
Tragic acci dents can oc cur if the op erator is not aler t to
the presen ce of ch ildren. Childr en are o ften at tracte d to
the mower and the mowing activity. T hey do not
understand the dangers . Never assume that children
will remain where you last s aw them.
1. Keep children out of the mowing area and under
the watchful ca re of a responsible adult other than
the operator.
2. Be alert and turn mower off if a chi ld enters the
area.
3. Before and while moving backwards, look behind
and down for small children .
4. Use extreme care when approaching blind co rners,
doorways, shrubs, trees, or othe r objects that may
obscure your vision of a child who may run into the
mower.
5. Keep children away from hot or running engines.
They can suffer burns from a ho t muffler.
6. Never allow children under 14 years old to operate
a power mower. Children 14 years old and over
should read and understand the operation
instructions and saf ety rules in this manual and
should be traine d and supervised by a parent.
Service
Safe Handling of Gasoline
1. To avoid personal injur y or property damage use
extreme care in handli ng gasoline. Gasoline is
extremely flammable an d the vapors are explosive.
Serious personal i njury can occur when gas oline is
spilled on yourself or your clothes which can ig nite.
2. Wash your skin and ch ange clothes immedia tely.
3. Use only an approv ed gasoline container .
4. Never fill containers inside a vehicle or on a tru ck or
trailer bed with a plastic li ner. Always place
containers on the ground away from your vehicle
before filling.
5. If possible, remov e gas-powered equipment fro m
the truck or trailer and refue l it on the ground. If this
is not possib le, then refuel suc h equipment on a
trailer with a portable cont ainer, rather than from a
gasoline dispens er nozzle.
6. Keep the nozzle in contact with the rim of the fuel
tank or container op ening at all times unti l fueling is
complete. Do no t use a nozzle lock-ope n device.
5
7. Extinguish all cigare ttes, cigars, pipes and other
sources of ignition.
8. Never fuel machine indo ors because flammable
vapors will accumul ate in the area.
9. Never remove g as cap or add fuel while the engine
is hot or running. Allow engine to cool at least two
minutes before refu eling.
10. Never over fill fuel tank. Fill tank to no more than ½
inch below bottom of fi ller neck to provide sp ace for
fuel expansion.
11. Replace gasoline cap an d tighten securely.
12. If gasoline is spil led, wipe it off the engine and
equipment. Move unit to an other area. Wait 5
minutes before starting the engi ne.
13. Never store the machin e or fuel container inside
where there is an open flame , spark or pilot light as
on a water hea ter, space heater, f urnace, clothes
dryer or other gas applianc es.
14. To reduce fire hazard, keep mower free of grass,
leaves, or other debris buil d-up. Clean up oil or fuel
spillage and remove an y fuel soaked debris.
15. Allow a mower to cool at least 5 min utes before
storing.
General Service
1. Never run an engine indoo rs or in a poorly
ventilated area. Engin e exhaust contains carbon
monoxide, an odorle ss and deadly gas.
2. Before cleaning, repair ing, or inspecting, make
certain the blade and all mo ving parts have
stopped. Disconnect the spark plug wire and
ground against the engine to prevent unintended
starting.
3. Check the blade and engine mo unting bolts at
frequent intervals for proper tightness . Also,
visually inspect blad e for damage (e.g., bent,
cracked, worn) Replace bla de with the original
equipment manufacture’ s (O.E.M.) blade only,
listed in this manual. “ Use of parts which do not
meet the original equipm ent specifications may
lead to improper performance and c ompromise
safety!”
4. Mower blades are sharp and can cut. Wrap the
blade or wear g loves, and use extra caution when
servicing them.
5. Keep all nuts, bolts, and sc rews tight to be sure the
equipment is in safe wor king condition.
6. Never tamper with safety devi ces. Check their
proper operation r egularly.
7. After striking a foreign object, stop the engine,
disconnect the spark plu g wire and ground against
the engine. Thoroughly inspect the mower for any
damage. Repair the damag e before starting and
operating the mower.
8. Never attempt to make a wheel or cutting height
adjustment while the eng ine is running.
9. Grass catcher co mponents, discharge cove r, and
trail shield are subjec t to wear and damage which
could expose moving pa rts or allow objects to be
thrown. For safety p rotection, frequently c heck
components and replace im mediately with original
equipment manufacturer’ s (O.E.M.) parts only ,
listed in this manual. “ U se of parts which do not
meet the original equipment s pecifications may
lead to improper performance and c ompromise
safety!”
10. Do not change the engine gov ernor setting or
overspeed the engine. T he governor controls the
maximum safe opera ting speed of the engine.
11. Maintain or replace s afety and instruction label s, as
necessary.
12. Observe proper dispos al laws and regulations.
Improper disposal of fluids and ma terials can harm
the environm ent.
Y our Responsibility
• Restrict the use of this power machine to persons
who read, understand and fol low the warnings and
instructions in this manual and on the machine.
1299 AC
6
SECTION 2: SLOPE GAUGE
15°
SIGHT AND HOLD THIS L EV EL WITH A VERTICAL TREE
A POWER POLE
A CORNER OF A BUILDING
OR A FENCE POST
F
O
L
D
O
N
D
O
T
T
E
D
L
I
N
E
,
R
E
P
R
E
S
E
N
T
I
N
G
A
1
5
°
S
L
O
P
E
USE THIS PAGE AS A GUIDE TO DETERMINE SLO PES WHERE YOU MAY NOT OPERATE SAFELY.
Do not mow on inclines with a slope in exces s of 15 degrees (a rise of appr oximately 2-1/2 feet ever y 10 feet). A riding mower cou ld overturn
and cause serious i njury. If op erating a wa lk-behind mower on such a s lope, it is extremely difficult t o maintai n your footi ng and you could s lip,
resulting in serious injur y.
Operate RIDING mowers up and down slopes, neve r across the face of slo pes.
Operate WALK-BEHIND m owers across the face of slopes, never up and do wn slopes.
WARNING