MTD 21A 450 Series 770 10194C User Manual To The 65076fae 6904 67b4 C1f0 4c4b513c5124

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Operator’s Manual

Rear Tine
Tiller
21A-450 Series

IMPORTANT: Read safety rules and instructions carefully before operating equipment.
Warning: This unit is equipped with an internal combustion engine and should not be used on or near any unimproved forestcovered, 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. 770-10194C.fm
(9/99)

TABLE OF CONTENTS
Content

Page

Important Safe Operation Practices................................................................... 3, 4
Loose Parts ...................................................................................................... 5
Assembling Your Tiller ....................................................................................... 6
Know Your Tiller................................................................................................. 8
Operating Your Tiller.......................................................................................... 9
Making Adjustments .......................................................................................... 10
Maintaining Your Tiller ....................................................................................... 11
Service............................................................................................................... 11
Off-Season Storage ........................................................................................... 13
Troubleshooting ................................................................................................. 13
Parts List............................................................................................................ 14

FINDING MODEL NUMBER
This Operator’s Manual is an important part of your new Tiller. It will help you assemble, prepare and
maintain the unit for best performance. Please read and understand what it says.
Before you start assembling your new equipment, please locate the model plate on the
equipment and copy the information from it in the space provided below. The information on
the model plate is very important if you need help from our Customer Support Department or
an authorized dealer.
•

You can locate the model number by standing in the operating position behind the unit and looking
down at the center of the rear tine cover. 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.

Copy the model number here:

Copy the serial number here:

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

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-(800)-800-7310 or 1-(330) 220-4MTD 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.

SECTION 1: IMPORTANT SAFE OPERATION PRACTICES
WARNING: 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 YOUR TILLER. FAILURE TO COMPLY WITH THESE INSTRUCTIONS MAY RESULT
IN PERSONAL INJURY. WHEN YOU SEE THIS SYMBOL— HEED ITS WARNING.

WARNING: The Engine Exhaust from this product contains chemicals known to the State of
California to cause cancer, birth defects or other reproductive harm.

DANGER: Your tiller 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 tiller is capable of amputating hands and feet. Failure to observe the following safety
instructions could result in serious injury or death.

GENERAL OPERATION
•

•

•
•

•

•
•
•

•

Read this operator’s manual carefully in its entirety
before attempting to assemble this machine. Read,
understand, and follow all instructions on the
machine and in the manual(s) before operation. Be
completely familiar with the controls and the proper
use of the machine before operating it. Keep this
manual in a safe place for future and regular
reference and for ordering replacement parts.
Your tiller is a powerful tool, not a plaything.
Therefore, exercise extreme caution at all times.
Your unit has been designed to perform one job: to
till soil. Do not use it for any other purpose.
Never allow children under age 14 to operate the
unit. Children 14 years and older should only
operate the unit under close parental supervision.
Only responsible individuals who are familiar with
these rules of safe operation should be allowed to
use your unit.
Do not operate tiller while under the influence of
alcohol or drugs.
Keep the area of operation clear of all persons,
particularly small children and pets. Stop the engine
when they are in the vicinity of your tiller.
Wear sturdy, rough-soled work shoes and close
fitting slacks and shirt. Shirt and slacks that cover
the arms and legs and steel-toed shoes are
recommended. Do not wear loose fitting clothes or
jewelry and secure hair so it is above shoulder
length. They can be caught in moving parts. Never
operate a unit in bare feet, sandals or sneakers.
Operate tiller only in daylight or good artificial light.
Do not start tiller unless the shift lever (if provided)
is in the neutral (N) position.
Do not allow anyone to stand or walk in front of tiller
when starting or running engine.

•

•
•

•

•
•
•
•
•
•

•

Do not place feet or hands on or near the tines
when starting the engine or while the engine is
running.
Never attempt to make depth bar, tine width, cable,
handle, or wheel adjustments while the engine is
running.
Do not leave the tiller unattended with the engine
running.
Before attempting to remove rocks, bricks and
other objects from tines, stop the engine and be
sure the tines have stopped completely. Disconnect
the spark plug wire and move it away from the
spark plug.
If your machine should start making an unusual
noise or vibration, immediately stop the engine and
allow the machine to come to a complete stop.
Disconnect the spark plug wire and move it away
from the spark plug. Take the following steps:
Inspect for damage.
Repair or replace any damaged parts.
Check for any loose parts and tighten to assure
continued safe operation.
Muffler and engine become hot and can cause a
burn. Do not touch.
Keep all shields, guards and safety devices in place
and operating properly.
Use caution when tilling near fences, buildings and
underground utilities. Rotating tines can cause
damage or injury.
Do not operate engine if air cleaner or cover over
carburetor air intake is removed, except for
adjustment. Removal of such parts could create a
fire hazard.
Only use accessories approved for this machine by
the manufacturer. Read, understand, and follow all
instructions provided with the approved accessory.

•

If situations occur which are not covered by this
manual, use care and good judgment. Contact your
dealer for assistance.

•
•

CHILDREN
•

•

•
•

Tragic accidents can occur if the operator is not
alert to the presence of small children. Children are
often attracted to the tilling activity. Never assume
that children will remain where you last saw them.
Keep children out of the work area and under the
watchful eye of a responsible adult other than the
operator.
Be alert and turn the unit off if a child enters the
area.
Never allow children under the age of 14 to operate
the tiller.

•

SERVICE
•

•

Use extreme care in handling gasoline and other
fuels. They are extremely flammable and the
vapors are explosive.
Store fuel and oil in approved containers, away
from heat and open flame, and out of the reach of
children. Check and add fuel before starting the
engine. Never remove gas cap or add fuel while the
engine is running. Allow engine to cool at least two
minutes before refueling.
Replace gasoline cap securely and wipe off any
spilled gasoline before starting the engine as it may
cause a fire or explosion.
Extinguish all cigarettes, cigars, pipes and other
sources of ignition.

•

•
•
•

Never refuel unit indoors because flammable
vapors will accumulate in the area.
Never store the machine or fuel container inside
where there is an open flame or spark such as a
gas hot water heater, space heater, clothes dryer or
furnace.
Never run your machine in an enclosed area as the
exhaust from the engine contains carbon
monoxide, which is a odorless, tasteless and
deadly poisonous gas.
To reduce fire hazard, keep engine and muffler free
of leaves, grass, and other debris build-up. Clean
up fuel and oil spillage. Allow unit to cool at least 5
minutes before storing.
Before cleaning, repairing, or inspecting, make
certain the tines and all moving parts have stopped.
Disconnect the spark plug wire and keep wire away
from spark plug to prevent accidental starting. Do
not use flammable solutions to clean air filter.
We do not recommend the use of pressure
washers to clean your unit. They may cause
damage to electric components, spindles, pulleys,
bearings or the engine. The use of pressure
washers will result in shortened life and reduce
serviceability.
Keep all nuts, bolts, and screws tight to be sure the
equipment is in safe working condition.
Never tamper with safety devices. Check their
proper operation regularly.
Do not alter or tamper with the engine’s governor
setting. The governor controls the maximum safe
operating speed of the engine. Overspeeding the
engine is dangerous and will cause damage to the
engine and to other moving parts of the machine.

WARNING — YOUR RESPONSIBILITY: 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.

Figure 1 Safety labels found on your unit

SECTION 2: LOOSE PARTS

Handle
Assembly

Control
Rod

NOTE: Cable tie not shown.

Depth
Stake
Assembly

SECTION 3: ASSEMBLING YOUR TILLER
IMPORTANT:This unit is shipped WITHOUT GASOLINE
or OIL. After assembly, see separate engine manual for
proper fuel and engine oil recommendations.

ATTACHING DEPTH STAKE ASSEMBLY

NOTE: Left and right is determined from the operator’s
position, standing behind the tiller.

•

TOOLS REQUIRED FOR ASSEMBLY
Adjustable Wrenches

•

Pair of Pliers
Screw Driver

•

TO REMOVE UNIT FROM CARTON
•

•
•
•
•
•

Remove staples, break glue on top flaps, or cut
tape at carton end and peel along top flap to open
carton.
Remove loose parts included with unit (i.e.,
operator’s manual, etc.).
Cut corners and lay carton down flat.
Remove packing material.
Roll or slide unit out of carton. Check carton
thoroughly for loose parts.
Extend control cable and lay on the floor. Be careful
not to bend or kink control cable.
T-Knob

•

Tip the tiller forward so it rests on front
counterweight.
Raise the tine shield hinge flap assembly. Remove
"T" knob, flat washer and hex bolt from depth stake.
Insert the depth stake assembly in front of spacer
(under the tine shield) and up through the tine
shield assembly as shown in Figure 2.
Insert clevis pin through the tine shield and the
second hole from top of the depth stake. Secure
with hairpin clip.
Insert hex bolt into the top hole of the depth stake
assembly. Place flat washer on hex bolt and thread
“T” knob onto the hex bolt. See Figure 2. Tighten
securely.
Tip the tiller back down so it rests on the depth
stake (transport position).

ATTACHING THE HANDLE ASSEMBLY
Remove
Handle
Ass’y

Hex Bolt

Washer

Depth
Stake

Handle
Bracket

T-Knob
Hex Bolt
Washer
Clevis Pin
Hairpin Clip

Figure 3
•

•
•

Depth Stake
Figure 2

Remove top two bolts and flange lock nuts from
handle mounting brackets as shown in Figure 3. Do
not remove the bottom bolt and nut.
Place handle assembly in position between the
handle mounting brackets. See Figure 3.
Line up holes in handle with holes in handle
mounting brackets. Secure with hardware removed
in step 1.

NOTE: Do not overtighten clutch cable. Too much
tension may cause it to break.

Slot Head Screw,
Nut, Flat Washers

WARNING: Be certain to check the
Internally Threaded
Tube

clutch cable adjustment as instructed on
this page before operating the tiller.
Secure clutch cable to handle using cable tie. Refer to
Figure 7. Cut off excess end of cable tie.

ATTACHING THE CONTROL ROD
•
Plastic Fitting

•

Figure 4

•

ATTACHING THE CLUTCH CABLE
.

Attach the clutch cable to the handle as follows (be
careful not to kink the cable).

•

•
•
•

•

Control Rod

Remove threaded eyebolt and nut from the end of
the cable.
Route the clutch cable to the right side of the
handle mounting brackets and underneath the
handle.
Push the cable through the hole in the center of the
handle and snap in the plastic fitting. See Figure 4.
Remove slot head screw, nut and two flat washers
from the clutch bail.
Fasten the threaded eyebolt onto bail as shown in
Figure 5. The parts go together from top to bottom
as follows: Slot Head Screw, Flat Washer, Clip,
Eyebolt, Flat Washer and 1/4” Nut.
Thread eyebolt and #10 nut, removed in step 1, into
the internally threaded tube at the end of the cable.
Thread engagement should be about 3/4”. Tighten
nut against tube at end of cable. See Figure 5.

Rubber
Washer
Idler
Pulley
Rod

Indicator Bracket
Hairpin
Clip

Figure 6

CHECKING THE CLUTCH ADJUSTMENT
IMPORTANT: Service the engine with oil and gasoline
before checking this adjustment. Refer to the separate
engine manual packed with your tiller for proper fuel
and engine oil recommendations.

Slot Head Screw

Clutch
Bail

Flat Washers
1/4”
Nut

Threaded
Eyebolt
#10
Nut

3/
4”

•

Remove hairpin clips from control rod, (rubber
washers to remain on control rod).
Insert the shorter, (angled), end of the control rod
through the indicator bracket on the shift cover and
secure with hairpin clip that was removed in step 1.
See Figure 6.
Insert the longer end of the control rod through the
hole in the gear selector handle and secure with
hairpin clip.See Figure 7.

Position the tiller so the front counterweight is against a
solid object, such as a wall. With the gear selection
lever in NEUTRAL, start the engine. Refer to the
separate engine manual.
Standing on the right side of the tiller, examine the belt
(inside the belt cover). It should not be turning.

Internally
Threaded
Tube

NOTE: Do not put fingers under the belt cover.
If the belt turns without bail engaged, adjust by
unthreading the internally threaded tube at the end of
the cable a few turns clockwise (when standing in
operator’s position), and then retighten the nut against
the tube.

Figure 5
7

Now move the shift lever to FORWARD (Wheels
Forward) position. Carefully engage the clutch by lifting
the clutch control bail against the handle. The wheels
should spin.

NOTE: A secondary cable adjustment is available if you
reach the point that additional adjustment is needed.
Remove the belt cover and move the hex nuts at the
other end of the cable towards the end of the casing.
Then readjust the hex nuts at the handle.

If the wheels do not spin with the unit in forward,
adjust by unthreading the tube at the end of the cable a
few turns counter-clockwise, (when standing in
operator’s position), and then retighten the nut against
the tube.

TIRE PRESSURE
The tires on your unit may be over-inflated for shipping
purposes. Reduce the tire pressure before operating
the unit. Recommended operating tire pressure is
approximately 20 p.s.i. (check sidewall of tire for tire
manufacturer’s recommended pressure).

Recheck both adjustments, and readjust as necessary.

WARNING: Maximum

tire
pressure
under any circumstances is 30 p.s.i.
Equal tire pressure should be maintained
on both tires.

SECTION 4: KNOW YOUR TILLER
CHOKE LEVER

Clutch
Control
Bail

Gear
Selection
Handle

The choke lever is located to the left of the throttle. It is
used to enrich the fuel mixture in the carburetor when
starting a cold engine. See Engine manual for further
information.

Height
Adjustment
Lever

GEAR SELECTION HANDLE
The gear selection handle is located in the center of the
handle on the tiller. It is used to select NEUTRAL,
REVERSE, or one of the FORWARD modes (see
below). Pull or push the handle so that the indicator on
top of shift cover points to the operating mode desired.
See Figure 7.

Clutch
Cable

Control
Rod

NEUTRAL—Transmission is in neutral.

Cable Tie

REVERSE—Reverse wheel drive.
FORWARD Modes:

Figure 7

Wheels Forward— Forward wheel drive only.

THROTTLE CONTROL

Tines Reverse— Forward wheel drive and reverse tine
drive.

The throttle control lever is located on the engine. It
controls the engine speed and stops the engine. See
Engine manual for further information.

Tines Forward— Forward wheel and tine drive.

WARNING: Make certain unit is in
NEUTRAL when starting the engine.
NOTE: If difficulty is encountered in moving the gear
selection handle, move the tiller forward or backward
slightly to allow the gears to synchronize.

CLUTCH CONTROL BAIL

DEPTH STAKE

The clutch control bail is located below the handle. See
Figure 7. Lifting the clutch control bail against the
handle engages the wheel and tine drive mechanisms.

The depth bar controls the tilling depth. Refer to
SECTION 5: OPERATING YOUR TILLER on this page.

HANDLE ADJUSTMENT

NOTE: Never engage clutch lever while shifting.

The handle may be adjusted to be raised or lowered in
line with the tiller. To adjust the handle position loosen
the handle height adjustment crank a few turns. Pivot
handle up or down to desired position. Tighten crank.

SECTION 5: OPERATING YOUR TILLER
NOTE: Engine is shipped without oil.

NOTE: After starting engine and prior to using the tiller,
be certain to check the clutch adjustment as described
in “Checking the Clutch Adjustment” section of
Assembly Instructions.

WARNING: Use the reverse tine drive
when tilling virgin ground, sod or hard
soil. Use the forward tine drive when
cultivating or tilling soft ground.

TO STOP ENGINE
•
•

BEFORE STARTING
•
•

Service engine with oil as instructed in the
separate engine manual packed with your unit.
Fill fuel tank with clean, fresh, lead-free, low-lead or
regular grade leaded gasoline.

NOTE: After the first ten hours of operation, recheck
the clutch adjustment. Refer to “Checking the Clutch
Adjustment” section of the Assembly Instructions.

TO START ENGINE

WARNING: When operating the tiller for
the first time, use the depth stake setting
that gives 1 inch of tilling depth (second
hole from the top). See Figure 8.

WARNING: Be sure no one is standing
in front of the tiller while the engine is
running or being started.
•
•

Tilling depth is controlled by the depth stake which can
be adjusted to five different settings. See Figure 8.
Adjust the side shields as shown in Figure 9, as you
adjust the depth stake. Be certain spark plug wire is
disconnected and grounded against the engine.

Place the throttle control lever in the FAST (rabbit)
position.
Move choke lever to CHOKE position.

NOTE: A warm engine may not require choking.
•

•

•
•

•

Move throttle control to the STOP position.
Disconnect spark plug wire and ground to prevent
accidentally starting while equipment is
unattended.

•

Stand at side of tiller. Grasp the starter handle with
your right hand and pull out slowly, until it pulls
slightly harder. Place your left hand on the lower
portion of the upper handle.
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 steps 3 and 4 until engine starts.
As engine warms up and begins to operate evenly,
move choke lever gradually to RUN position. If
engine falters, return to choke position, then slowly
move to RUN position.
Refer to engine manual for additional engine
information.

•

When using the tiller for the first time, use the
second adjustment hole from the top (1" of tilling
depth). See Figure 8.
When breaking up sod and for shallow cultivation,
use the setting which gives 1" of tilling depth
(second hole from the top). Place the side shields in
their lowest position. For further depth, raise the
depth stake and side shields and make one or two
more passes over the area.
When tilling loose soil, depth stake may be raised
to its highest position (use bottom adjustment hole)
to give the deepest tilling depth. Raise the side
shields to their highest position.

TO OPERATE THE TILLER:
•
•
•

Select the depth stake setting.
Start engine as instructed on page 9.
Move gear selection handle to one of the forward
modes or reverse.
Use the reverse tine drive when tilling virgin
ground, sod or hard soil. Use the forward tine
drive when cultivating or tilling soft ground.

Transport
Position

Use This
Position
First Time
Clevis
Pin

IMPORTANT: When using the forward tine drive, lower
the depth stake (use a shallower tilling depth) to make
certain the tines do not run across the ground.

WARNING: Do not move the gear

Hairpin
Clip

selection handle with the wheels or tines
engaged. Make certain the unit is stopped
completely before changing the gear
selection.

Figure 8
•
•

•

To transport tiller, lower the depth stake (use top
adjustment hole).
To adjust the depth stake, remove the clevis pin
and hairpin clip. See Figure 8. Move the depth
stake to the desired setting.
To adjust the side shields, remove the front wing
nut and loosen the rear wing nut. See Figure 9.
Place side shield in position desired. Replace wing
nuts and tighten securely.

Use This
Hole for
Lowest (Shallowest)
Position

•

NOTE: Make certain the gear selection indicator is
correctly positioned before engaging the clutch handle.
If it is between gears, the engine will stall.
To transport tiller, do not engage the tines. Select the
wheel drive only.

WARNING: Do not push down on the

Side
Shields

handles so that the wheels are lifted off
the ground while using the reverse tine
drive, or the tiller could move backward
and cause personal injury.
For best results, it is recommended the garden be tilled
twice (lengthwise, then widthwise) to pulverize the soil.

Rear
Wing Nut

Front
Wing Nut

Squeeze the clutch control bail against the handle
to engage the wheels and tines.

Use This Hole for
Highest (Deepest)
Position
Figure 9

SECTION 6: MAKING ADJUSTMENTS
HANDLE ADJUSTMENT

To adjust the tension on the belt, refer to clutch
adjustment information in “Checking the Clutch
Adjustment” section of the Assembly Instructions. After
belt tension has been adjusted, if the belt is excessively
stretched, you may need to adjust the idler pulley rod.
This can easily be checked. With the engine off and the
clutch control bail disengaged, shift the gear selection
handle to each forward mode. If the indicator bracket
touches the idler pulley rod, (with the clutch control bail
disengaged), then an adjustment is necessary.

The handle height may be adjusted. Refer to the Know
Your Tiller section for details of handle adjustment.

BELT TENSION ADJUSTMENT
Periodic adjustment of the belt tension may be required
due to normal stretch and wear on the belt. Adjustment
is needed if the tines or wheels seem to hesitate while
turning, but the engine maintains the same speed.

•
10

Disconnect and ground out spark plug wire against
the engine.

•
•
•
•
•

CARBURETOR ADJUSTMENT

Remove the belt cover as described in the belt
replacement section on page 12.
Remove the hairpin clip and spring washer from the
idler pulley rod. See Figure 11.
Move the idler pulley rod to the lower hole in the
idler bracket. See Figure 11.
Replace the spring washer and hairpin clip.
Check clearance of the idler pulley rod to the
indicator bracket by shifting to each forward mode,
as before.

WARNING: If any adjustments are made
to the engine while the engine is running,
(e.g. carburetor), disengage all clutches
and tines. Keep clear of all moving parts.
Be careful of heated surfaces and muffler.
Never make unnecessary adjustments. The factory
settings are correct for most applications. If
adjustments are needed, refer to the separate engine
manual packed with your tiller.

SECTION 7: SERVICE
Transmission—The transmission is pre-lubricated and
sealed at the factory. It requires no checking unless the
transmission is disassembled. To fill with grease, lay
the right half of the transmission on its side. Add 30
ounces of Benalene 920 grease. Apply a bead of RTV
or silicone sealant to the right half of the transmission,
all the way around the gear compartment. Assemble
the left half to it. This grease can be obtained at your
nearest authorized dealer. Order part number 7370300.

Clutch Bail—Lubricate the pivot point on the clutch bail
and the cable at least once a season with light oil. The
control must operate freely in both directions.
Pivot Points—Lubricate all pivot points and linkages at
least once a season with light oil.
Tine Shaft—Remove tines at least once a season and
lubricate with oil.
Wheel Axle—Remove the wheel assemblies at least
once a season and lubricate with oil.

SECTION 8: MAINTAINING YOUR TILLER
WARNING: Disconnect the spark plug

Maintain engine oil as instructed in the separate
engine manual packed with your unit. Read and follow
instructions carefully.

wire and ground it against the engine
before performing any repairs or
maintenance.

Service air cleaner every ten hours under normal
conditions. Clean every hour under extremely dusty
conditions. Poor engine performance and flooding
usually indicates that the air cleaner should be
serviced. To service the air cleaner, refer to the
separate engine manual packed with your unit.

ENGINE
Refer to the separate engine manual for engine
maintenance instructions.

IMPORTANT: Never run your engine without air cleaner
completely assembled.

The spark plug should be cleaned and the gap reset
every 25 hours of engine operation. Spark plug
replacement is recommended at the start of each tiller
season; check engine manual for correct plug type and
gap specification.
Clean the engine regularly with a cloth or brush. Keep
the cooling system (blower housing area) clean to
permit proper air circulation which is essential to engine
performance and life. Be certain to remove all dirt and
combustible debris from muffler area.

CLEANING THE TINE AREA
Torx Screws

Clean the underside of the tine shield after each use.
The dirt washes off the tines easier if washed off
immediately instead of after it dries.
We do not recommend the use of pressure washers to
clean your unit. They may cause damage to electric
components, spindles, pulleys, bearings, or the engine.
The use of pressure washers will result in shortened life
and reduce serviceability.

Belt Cover

Hex Cap Nut
Flat Washer

BELT REPLACEMENT
Self Tap
Screw

CAUTION: Do not use an off-the-shelf
belt.

Figure 10
Upon reassembly, make certain the belt is routed over
the idler pulley and inside of belt keepers by engine
pulley. See Figure 11.

Your tiller has been engineered with a belt made of
special material (Kevlar Tensile) for longer life and
better performance. It should not be replaced with an
off-the-shelf belt.

Idler
Pulley
Rod

If belt replacement is required, order belt by part
number from your nearest authorized dealer.
Part No. 754-0434—‘‘V’’ Belt
•
•

•

Disconnect and ground the spark plug wire against
the engine.
Remove the belt cover from the left side of the tiller
as follows: See Figure 10.Remove two torx screws
from the top of belt cover.
Remove the hex cap nut and flat washer from the
side of the belt cover. Remove the self-tap screw at
the bottom of the front of the cover.
Remove the belt keeper bracket located behind the
engine pulley by removing two hex bolts and lock
washers. See Figure 11.
Remove belt. Reassemble new belt, following
instructions in reverse order.

Engine
Pulley Belt Keeper
Brkt.
Figure 11

Idler
Brkt.

TIRES
Recommended operating tire pressure is
approximately 20 p.s.i. (check sidewall of tire for tire
manufacturer’s recommended pressure). Maximum tire
pressure under any circumstances is 30 p.s.i. Equal tire
pressure should be maintained on both tires.
When installing a tire to the rim, be certain rim is clean
and free of rust. Lubricate both the tire and rim
generously. Never inflate to over 30 p.s.i. to seat beads.

WARNING: Excessive pressure (over 30
p.s.i.) when seating beads may cause tire/
rim assembly to burst with force
sufficient to cause serious injury.

SECTION 9: OFF-SEASON STORAGE
If the tiller will not be used for a period longer than 30
days, the following steps should be taken to prepare the
tiller for storage.
•

•

•
•
•

Clean the exterior of engine and the entire tiller
thoroughly. Lubricate the tiller as described in the
lubrication instructions.
We do not recommend the use of pressure
washers to clean your unit. They may cause
damage to electric components, spindles, pulleys,
bearings or the engine. The use of pressure
washers will result in shortened life and reduce
serviceability.

Refer to the engine manual for correct engine
storage instructions.
Wipe tines with oiled rag to prevent rust.
Store tiller in a clean, dry area. Do not store next to
corrosive materials, such as fertilizer.

NOTE: When storing any type of power equipment in
an unventilated or metal storage shed, care should be
taken to rustproof the equipment. Using a light oil or
silicone, coat the equipment, especially any springs,
bearings and cables.

SECTION 10: TROUBLE SHOOTING GUIDE
Trouble

Possible Cause(s)

Corrective Action

Engine fails to
start

Fuel tank empty, or stale fuel.

Fill tank with clean, fresh gasoline. Fuel will not last over
thirty days unless a fuel stabilizer is used.
Move throttle lever to start position.

Engine runs
erratic

Engine overheats

Tines do not
engage

Tines skip over
ground
Wheels do not
engage

Throttle control lever not in correct
starting position (if so equipped).
Blocked fuel line.
Dirty aircleaner.
Choke not in ON position.
Spark plug wire disconnected.
Faulty spark plug.
Engine flooded.
Unit running on CHOKE.
Spark plug wire loose.
Blocked fuel line or stale fuel.
Vent in gas cap plugged.
Water or dirt in fuel system.
Dirty air cleaner.
Carburetor out of adjustment.
Engine oil level low.
Dirty air cleaner.
Air flow restricted.
Carburetor not adjusted properly.
Foreign object lodged in tines.
Tine clevis pin(s) missing.
Pulley and idler not in correct
adjustment.
Not shifting properly.
Control cable not adjusted properly.
Belt worn and/or stretched.
Improper rotation.
Clevis pin missing.
Tiller is not being shifted properly.
Control cable not adjusted properly.
Belt worn and/or stretched.

Clean fuel line.
Refer to the engine manual packed with your unit.
Move switch to ON position.
Connect wire to spark plug.
Clean, adjust gap or replace.
Refer to the engine manual packed with your unit.
Move choke lever to OFF position.
Connect and tighten spark plug wire.
Clean fuel line; fill tank with clean, fresh gasoline. Fuel will
not last over thirty days unless a fuel stabilizer is used.
Clear vent.
Drain fuel tank. Refill with fresh fuel.
Refer to the engine manual packed with your unit.
Refer to the engine manual packed with your unit.
Fill crankcase with proper oil.
Refer to the engine manual packed with your unit.
Refer to the engine manual packed with your unit.
Adjust carburetor as instructed in separate engine manual.
Dislodge foreign object.
Replace tine clevis pin(s).
Take unit to authorized service dealer.
Refer to Controls section of operator’s manual for proper
shifting procedures.
Adjust control cable (see assembly instructions).
Replace belt.
Forward rotation should only be used on soil that has
already been tilled, not on virgin soil.
Replace clevis pin.
Refer to Controls section of operator’s manual for proper
shifting procedures.
Adjust control cable (see assembly instructions).
Replace belt.

NOTE: For repairs beyond the minor adjustments above, contact your local authorized service dealer.
13

SECTION 11: PARTS LIST FOR MODEL 450 SERIES

MODEL 450 SERIES

REF.
NO.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27

PART NO.
611-0020
611-0021
611-0128
611-0129
617-0058
617-0059
617-0060
617-0061
617-0062
686-0108
710-0376
710-0599
710-0604
710-3008
711-1349
712-0378
712-3004A
713-0367
713-0484
716-0865
717-0853
717-1582
717-1583
717-1584
717-1585
717-1587
717-1594

REF.
NO.

DESCRIPTION

28
29
31
32
33
34
35
36
37
40
41
42
43
44
45
46
47
48
49
50
51
52
53
-

Wheel Shaft Ass’y: 33T
Tine Shaft Ass’y: 18T
Jack Shaft Ass’y
Input Shaft Ass’y
Rev. Idler Gear Ass’y: 30T
Ftine Idler Gear Ass’y: 30T
Tine Input Sprocket Ass’y: 9T
Wheel Input Sprocket Ass’y: 10T
Gear Ass’y: 11T
R.H. Housing Ass’y
Hex Bolt 5/16-18 x 1" Lg.
Hex S-Tap Scr. 1/4- 20 x .5"
Hex S-Tap Scr. 5/16-18 x .625"
Hex Bolt 5/16-18 x .75"
Input Shaft
Hex Nut 7/16-20
Flange Nut 5/16-18
#420 Chain 1/2 Pitch x 50 Links
#50 Chain 5/8 Pitch x 54 Links
Snap Ring
Shifting Fork
Spur Gear 44T
Spur Gear 30T
Spur Gear 30T
Spur Gear 44T
Spur Gear 44T
Spur Gear 16T

PART NO.
721-0378
721-0379
726-0277
732-0496
736-0163
736-0351
736-0407
736-0518
736-3088
738-0645
738-0648
738-1013
741-0124
741-0420
741-0421
741-0563
741-0862
750-0258
750-0570
750-0664
750-0671
786-0171
786-0238
737-0300
737-0288
686-0107

DESCRIPTION
Seal 1.0 Shaft
Seal .75 Shaft
Taper Cap Ring
Compression Spring .50" Lg.
Thrust Wash. 1.03" I.D. x 1.62" O.D.
Fl-Wash .76" I.D. x 1.5" O.D.
Bell-Wash .45" I.D. x 1.0"
Thrust Wash. .445 x 1.92 x .060
Fl-Wash. .635" I.D. x 1.59 O.D.
Detent Shaft 1/2" Dia.
Jack Shaft .625 x 2.385
Jack Shaft .625 x 5.0
Ball Bearing
Flange Bearing 1.0 x 2.5 x 1.38
Flange Bearing .75 x 2.5 x 1.38
Ball Bearing . 6692 x 5745 x .466
Detent Ball .250
Spacer .315
Spacer 1.0 I.D x 2.0 O.D. x .440
Spacer .505 I.D. x .88 O.D. x .440
Spacer .75 x 2.0 x .50
L.H. Chain Case Ass’y
Gear Positioner Bracket
Benelene 920 Grease
Never Seez Grease
Gear Case Assembly Complete

NOTE: For painted parts, please refer to the list of color codes below. Please add the applicable color code, wherever
needed, to the part number to order a replacement part. For instance, if a part numbered 700-xxxx is painted Oyster Gray, the
part number to order would be 700-xxxx-0662.
Black — 0691; Black, Powder — 0637; Blue, Midnight — 0667; Charcoal — 0483; Grey — 0648;
Grey, Oyster — 0662; Orange — 0606; Red — 0650; Red, MTD — 0638; Silver — 0629; Yellow — 0674.

MODEL 450 SERIES

2
22

12 15
12

60
61

17
10
23
18

8
3
14

11
6

16
61
4
62

34
27
64

21
30
38

39
63

26
32

36
33
31

46
42

29
66
49

30
41

30
24

44
26

28
35

50
59

51
65

53
55
56
54
57

MODEL 450 SERIES

REF.
NO.
1
2
3
4
5
6
7
8
9
10
11
12
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33

PART NO.
747-1152
649-0041
649-0034
710-3005
710-3056
711-0415
712-0379
712-0429
714-0147
720-0313
720-0210A
720-0278A
726-0317
735-0246
736-0117
736-0242
738-0958
784-0190
784-0191
786-0120
747-1219
786-0181
686-0044A
710-0176
710-3008
710-3097
712-0421
736-0169
712-3004A
726-0106
738-0849
747-0432

REF.
NO.

DESCRIPTION

34
35
36
37
38
39
40
41
42
44
46
49
50
51
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70

Shift Rod
Upper Handle Ass’y
Lower Handle Ass’y
Hex Screw 3/8-16 x 1.25
Hex Screw 5/16-18 x 3.25
Clevis Pin 3/8-1.62
Flange Lock Nut 3/8-24
Hex Lock Nut 5/16-18
Cotter Pin
Grip
T-Knob
Foam Grip
Cable Tie
Plug
Flat Washer 3/8 x .620 x .033
Bell Wash. .340 I.D. x .872 O.D.
Shoulder Spacer
Handle Adjustment Crank
Hex Nut Ret. Bracket
Depth Stake
Bail Clutch
Shift Lever Rod
Tine Shield Cover Ass’y
Hex Cap Screw 5/16-18 x 2.75
Hex Cap Screw 5/16-18 x .750
Carriage Bolt 3/8-16 x 1.0
Wing Nut
Lock Washer 3/8
Flange Nut 5/16-18
Cap Nut
Hex Screw 5/16-18 x .75" Lg.
Rod

PART NO.
750-0885
786-0090
786-0113
786-0176
786-0177
786-0178
786-0179
786-0180
686-0109
710-1017
715-0120
784-0208C
711-0415
712-3054
742-0305
738-0689
736-0208
736-0253
738-0688
784-0160
714-0149B
735-0127
714-0104
710-3022
736-0204
712-0431
736-0169
712-0798
710-0946
712-0324
726-0273
736-3090

Labels
Ref.
No.

Part No.

N/I
N/I
N/I
N/I
N/I
N/I

777S30037
777I20282
777D02195
777D01524
777I20358
777I20451

Code

Description
Model Plate
Shift Plate Facing Operator
Engine Spinner
YM, Side of Belt Guard
Place Hand Here on Handle
Gear Selection on Handle

DESCRIPTION
Spacer .435 O.D. x .322 I.D.
Shoulder
Tine Shield Hinge Flap
R.H. Handle Brkt.
L.H. Handle Brkt.
Tine Shield
Tine Shield Brkt.
Shoulder Spacer Brkt.
Shift Crank Ass’y
Screw 1/4-14 x .625
Spirol Pin 3/16 x 1.00
Shift Cover
Clevis Pin
Hex Nut 3/8-24 Thd.
13" Dia. Articulating Tine
Shld. Bolt 1/2" DIa. x .175
Fl-Wash. .51" I.D. x 1.50"
Bell-Wash. .515" I.D. x 1.14"
Shld. Bolt 1/2" Dia x .320
Tine Adapter Ass’y 18"
Internal Cotter Pin
Rubber Washer
Cotter Pin
Hex Screw 3/8-16 x 2.75" Lg.
Flat Washer
Flange Nut .344 I.D. x .62 O.D.
Lock Washer
Hex Nut 3/8-16
Truss Screw 1/4-20 x .65
Hex Lock Nut 1/4-20 Gr. 8
Battery Hose Clamp 5/16
Flat Washer .260 x .720 x .060

MODEL 450 SERIES

27
46
45

9
19
26

8
10

25
14

2
11

28
13

15
44

3 40

22
4
23

43
42

41
39

35
38
37
36
37

31
30

MODEL 450 SERIES

REF.
NO.
1
2
3
4

PART NO.
686-0111
710-0237
710-0412
710-0502A

5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24

710-0591
710-0599
710-0723
712-0266
712-0267
714-0104
736-0104
736-0119
736-0176
736-0271
736-0329
736-0452
738-0876
746-1117
747-1159
754-0434
756-0405
756-0971
756-0972
756-1162

DESCRIPTION
Belt Cover Brkt. Ass’y
Hex Bolt 5/16-24 x .62" Lg.
Hex Bolt 1/4-28 x .75" Lg.
Hex Wash.TT-Sems Screw 3/8-16 x
1.250" Lg.
Hex Bolt 3/8-24 x 1.00
Hex Wash. Hd. S-Tap Scr.
Hex Cap Screw 3/8-16 x 1.25
Ctr. Lock Jam Nut 3/8-16
Hex Nut 5/16-18
Internal Cotter Pin
Hairpin Clip
L-Wash. 5/16" I.D.
Fl-Wash. 1/4 I.D. x .93 O.D.
Spring-Wash. .317 x .625 O.D. x .099
L-Wash. 1/4" I.D.
Bell-Wash. .396 x 1.140 x .095
Shld. Nut 7/16-20
Clutch Cable
Idler Pulley Rod
Belt: 4L x 58.16 Lg.
Fl-Idler w/Flange 3.75" O.D.
Outer Engine Pulley Half
Inner Engine Pulley Half
Input Pulley

REF.
NO.
25
26
27
28
29

30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46

PART NO.
786-0064A
786-0186
786-0187
786-0193
634-0110
634-0111
734-1796
634-0112
734-0255
711-1017
714-0104
710-0382
712-0206
723-0381
736-0326
736-0921
710-0653
710-1017
712-0392
736-0463
784-0158A
710-0805
736-0242
712-3010

DESCRIPTION
Idler Bracket
Belt Keeper Brkt.
Shift Cover Brkt.
Idler Belt Keeper
RH Wheel Ass’y Comp. 16.0 x 4.0
LH Wheel Ass’y Comp. 16.0 x 4.0
Tire Only 16.0 x 4.0
Wheel Rim Ass’y Comp.
Air Valve
Clevis Pin
Internal Cotter Pin
Hex Bolt 1/2-13 x 5.00" Lg.
Hex Nut 1/2-13 Thd.
Counterweight
Fl-Wash. .510" I.D. x 1.0" O.D.
L-Wash. 1/2" Lg.
Hex Screw 1/4-20 x .375" Lg.
Screw 1/4-14 x .625" Lg.
Acorn Lock Nut
Fl-Washer 1/4 x .620" Lg.
Belt Cover
Hex Bolt 5/16-18 x 1.50" Lg.
Bell-Wash. .340 I.D. x .872 O.D.
Nut:Hex 5/16-18

MANUFACTURER’S
LIMITED WARRANTY
The limited warranty set forth below is given by MTD
PRODUCTS INC (“MTD”) with respect to new merchandise purchased and used in the United States, its possessions and territories.
MTD warrants this product against defects in material and
workmanship for a period of two (2) years commencing on
the date of original purchase and will, at its option, repair or
replace, free of charge, any part found to be defective in
material or workmanship. This limited warranty shall only
apply if this product has been operated and maintained in
accordance with the Operator’s Manual furnished with the
product, and has not been subject to misuse, abuse, commercial use, neglect, accident, improper maintenance,
alteration, vandalism, theft, fire, water or damage because
of other peril or natural disaster. Damage resulting from the
installation or use of any accessory or attachment not
approved by MTD Products Inc. for use with the product(s)
covered by this manual will void your warranty as to any
resulting damages.
Normal wear parts or components thereof are subject to
separate terms as follows: All normal wear part or component failures will be covered on the product for a period of
90 days regardless of cause. After 90 days, but within the
two year period, normal wear part failures will be covered
ONLY IF caused by defects in material or workmanship of
OTHER component parts. Normal wear parts and components include, but are not limited to, belts, blades, blade
adapters, grass bags, rider deck wheels, seats, snow
thrower skid shoes, shave plates and tires. Batteries are
covered by a 90-day limited replacement warranty.
HOW TO OBTAIN SERVICE: Warranty service is available, WITH PROOF OF PURCHASE THROUGH YOUR
LOCAL AUTHORIZED SERVICE DEALER. To locate the
dealer in your area, please check for a listing in the Yellow
Pages or contact the Customer Service Department of
MTD PRODUCTS INC by calling 1-800-800-7310 or writing to P.O. Box 368022, Cleveland, Ohio 44136-9722.
This limited warranty does not provide coverage in the
following cases:
a. The engine or component parts thereof. These items
carry a separate manufacturer’s warranty. Please
refer to the applicable manufacturer’s warranty on
these items.
b. Log splitter pumps, valves and cylinders have a separate one year warranty.

c. Routine maintenance items such as lubricants, filters,
blade sharpening and tune-ups, or adjustments such
as brake adjustments, clutch adjustments or deck
adjustments; and normal deterioration of the exterior
finish due to use or exposure.
d. MTD does not extend any warranty for products sold
or exported outside of the United States of America,
its possessions and territories, except those sold
through MTD’s authorized channels of export distribution.
No implied warranty, including any implied warranty of
merchantability or fitness for a particular purpose,
applies after the applicable period of express written
warranty above as to the parts as identified. No other
express warranty or guaranty, whether written or oral,
except as mentioned above, given by any person or
entity, including a dealer or retailer, with respect to any
product shall bind MTD. During the period of the Warranty, the exclusive remedy is repair or replacement of
the product as set forth above. (Some states do not
allow limitations on how long an implied warranty lasts, so
the above limitation may not apply to you.)
The provisions as set forth in this Warranty provide the
sole and exclusive remedy arising from the sales. MTD
shall not be liable for incidental or consequential loss
or damages including, without limitation, expenses
incurred for substitute or replacement lawn care services, for transportation or for related expenses, or for
rental expenses to temporarily replace a warranted
product. (Some states do not allow the exclusion or limitation of incidental or consequential damages, so the above
exclusion or limitation may not apply to you.)
In no event shall recovery of any kind be greater than the
amount of the purchase price of the product sold. Alteration
of the safety features of the product shall void this Warranty. You assume the risk and liability for loss, damage, or
injury to you and your property and/or to others and their
property arising out of the use or misuse or inability to use
the product.
This limited warranty shall not extend to anyone other than
the original purchaser, original lessee or the person for
whom it was purchased as a gift.
How State Law Relates to this Warranty: This limited
warranty gives you specific legal rights, and you may also
have other rights which vary from state to state.

Source Exif Data:

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Create Date                     : 1999:09:22 10:23:11
Producer                        : Acrobat Distiller 4.0 for Windows
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Title                           : 770-10194C.fm
Modify Date                     : 1999:09:28 11:58:55-04:00
Page Count                      : 20

EXIF Metadata provided by EXIF.tools

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