Lawn-Boy SilverPro Series User manual

Operator’s Manual
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Lawn-Boy Inc., Attn.: Parts Dept., 8111 Lyndale Ave S, Bloomington, MN 55420-1196.
Domestic English (EN)
Form No. 3324-469 Rev A
SilverPro Series
Walk Power Lawn Mower
Model No. 10247—200000001 and Up
Model No. 10252—200000001 and Up
Model No. 10323—200000001 and Up
Model No. 10324—200000001 and Up

2001 Lawn-Boy, Inc.
All Rights Reserved Printed in USA
2
The engine exhaust from this product contains
chemicals known to the State of California to
cause cancer, birth defects, or other reproductive
harm.
WARNING
IMPORTANT: This engine is not equipped with a spark
arrester muffler. It is a violation of California Public
Resource Code Section 4442 to use or operate this engine
on any forest–covered, brush–covered or grass–covered
land. Other states or federal areas may have similar laws.
This spark ignition system complies with Canadian
ICES-002.
Ce système d’allumage par étincelle de véhicule est
conforme à la norme NMB-002 du Canada.
The enclosed Engine Owner’s Manual is supplied for
information regarding The U.S. Environmental
Protection Agency (EPA) and the California Emission
Control Regulation of emission systems, maintenance
and warranty.
Keep this engine Owner’s Manual with your unit.
Should this engine Owner’s Manual become damaged
or illegible, replace immediately. Replacements may be
ordered through the engine manufacturer.
Contents
Page
Introduction 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Safety 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Lawn Mower Safety 3. . . . . . . . . . . . . . . .
Safety and Instruction Decals 6. . . . . . . . . . . . . . .
Assembly 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unfolding the Handle 6. . . . . . . . . . . . . . . . . . . . . .
Adjusting the Handle Height 7. . . . . . . . . . . . . . . .
Before Starting 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mixing Gasoline and Oil 7. . . . . . . . . . . . . . . . . . .
Operation 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starting the Engine 9. . . . . . . . . . . . . . . . . . . . . . . .
Stopping the Engine 9. . . . . . . . . . . . . . . . . . . . . . .
Using the Self-propel Drive 10. . . . . . . . . . . . . . . . .
Adjusting the Cutting Height 10. . . . . . . . . . . . . . . .
Operating Tips 10. . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended Maintenance Schedule 12. . . . . . . .
Cleaning the Lawn Mower Housing 13. . . . . . . . . .
Cleaning the Self-propel Drive 14. . . . . . . . . . . . . .
Lubricating the Self-propel Drive 14. . . . . . . . . . . .
Adjusting the Self-propel Drive Cable 14. . . . . . . .
Servicing the Air Filter 15. . . . . . . . . . . . . . . . . . . .
Maintaining the Spark Plug 15. . . . . . . . . . . . . . . . .
Maintaining the Blade 16. . . . . . . . . . . . . . . . . . . . .
Cleaning the Exhaust Port 17. . . . . . . . . . . . . . . . . .
Storage 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preparing the Fuel System 18. . . . . . . . . . . . . . . . . .
Preparing the Engine 18. . . . . . . . . . . . . . . . . . . . . .
General Information 18. . . . . . . . . . . . . . . . . . . . . . .
Folding the Handle 19. . . . . . . . . . . . . . . . . . . . . . . .
Removing from Storage 19. . . . . . . . . . . . . . . . . . . .
Accessories 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installing a Rear Grass Catcher 19. . . . . . . . . . . . . .
Installing the Cover Plate 22. . . . . . . . . . . . . . . . . . .
Installing the Mulch Plate 22. . . . . . . . . . . . . . . . . .
Troubleshooting 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Federal Emission Control Warranty Statement 26. . . . .
The Lawn-Boy No-Worry Warranty 28. . . . . . . . . . . . .
IMPORTANT: The two-stroke engine provided on this
product meets the EPA Phase I Non-Road Emissions
regulations for engines under 19 kW. This product does
not meet CARB TIER 1 regulations and cannot be sold
in California.
Introduction
Thank you for choosing a Lawn-Boy product. We want
you to be completely satisfied with your new purchase.
Read this manual carefully to learn how to operate and
maintain your product properly. The information in this
manual can help you and others avoid injury and product
damage. Although Lawn-Boy designs and produces safe
products, you are responsible for operating the product
properly and safely.
Whenever you contact your Authorized Service Dealer or
the factory for help with service, genuine Lawn-Boy parts,
or additional information, have the model number and the
serial number of your product handy. You will find the
model number and serial number decal on the product as
illustrated in Figure 1.
1064
1
Figure 1
1. Modelnumber and serial number decal
Write the product model number and serial number in the
space below:

3
Model No.
Serial No.
This manual identifies potential hazards and has special
safety messages that help you and others avoid personal
injury and even death. DANGER, WARNING, and
CAUTION are words used to identify the level of hazard.
DANGER signals an extreme hazard that will cause
serious injury or death if you do not follow the
recommended precautions.
WARNING signals a hazard that may cause serious injury
or death if you do not follow the recommended
precautions.
CAUTION signals a hazard that may cause minor or
moderate injury if you do not follow the recommended
precautions.
This manual uses two other words to highlight
information. Important calls attention to special
mechanical information and Note emphasizes general
information worthy of special attention.
Safety
This lawn mower meets or exceeds CPSC blade safety
requirements for walk-behind rotary mowers and the
B71.1 specifications of the American National
Standards Institute, in effect at time of production.
Lawn-Boy designed this lawn mower for cutting and
mulching grass, or, when equipped with a grass bag, for
catching cut grass. Any use for purposes other than these
could prove dangerous to the operator or to bystanders.
Note: The engine on this lawn mower is not equipped
with a spark arrester muffler. Operating this lawn mower
on any forest-covered, brush-covered, or unimproved
grass-covered land without an approved spark arrester
muffler may violate your state law.
WARNING
POTENTIAL HAZARD
•Engine exhaust contains carbon monoxide,
which is an odorless, deadly poison.
WHAT CAN HAPPEN
•Carbon monoxide can kill you.
HOW TO AVOID THE HAZARD
•Do not run the engine indoors or in an enclosed
area.
To ensure maximum safety, best performance, and to
gain knowledge of the product, it is essential that you
and any other operator of the lawn mower read and
understand the contents of this manual before the
motor is ever started. Pay particular attention to the
safety alert symbol which means CAUTION,
WARNING, OR DANGER — “personal safety
instruction.” Read and understand the instruction
because it has to do with safety. Failure to comply with
instruction may result in personal injury.
General Lawn Mower Safety
The following instructions have been adapted from the
ANSI/OPEI standard B71.1—1998 and ISO standard
5395:1990(E). Information or terminology specific to
Lawn-Boy lawn mowers is enclosed in parenthesis.
This cutting 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
•Read the instructions carefully. Be familiar with the
controls and the proper use of the equipment before
starting.
•See manufacturer’s instructions for proper operation
and installation of accessories. Only use accessories
approved by the manufacturer.
•Never allow children or people unfamiliar with these
instructions to use the mower. Local regulations may
restrict the age of the operator.
•Never mow while people, especially children, or pets
are nearby. Stop mower if anyone enters the area.
Tragic accidents can occur if the operator is not alert to
the presence of children. Children are often attracted to
the mower and the mowing activity. Never assume that
children will remain where you last saw them.
•Keep children out of the mowing area and under the
watchful care of a responsible adult.
•Be alert and turn mower off if children enter the area.

4
•Use extra care when approaching blind corners,
shrubs, trees, or other objects that may obscure vision.
•Keep in mind that the operator or user is responsible
for accidents or hazards occurring to other people or
their property.
Preparation
•While mowing, always wear substantial footwear and
long trousers.
•Do not operate the equipment when barefoot or
wearing open sandals.
•Always wear safety goggles or safety glasses with side
shields when operating mower.
•Thoroughly inspect the area where the equipment is to
be used and remove all stones, sticks, wires, bones,
and other foreign objects.
•Warning: Gasoline is highly flammable. Take the
following precautions:
– Store fuel in containers specifically designed for
this purpose.
– Refuel outdoors only and do not smoke while
refuelling.
– Add fuel before starting the engine. Never remove
the cap of the fuel tank or add gasoline while the
engine is running or when the engine is hot.
– If gasoline is spilled, do not attempt to start the
engine but move the machine away from the area
of spillage and avoid creating any source of
ignition until gasoline vapors have dissipated.
– Replace all fuel tank and container caps securely.
– If the fuel tank has to be drained, do this outdoors.
•Replace faulty mufflers.
•Before using, always visually inspect to see that the
blades, blade bolts, and cutter assembly are not worn
or damaged. Replace worn or damaged blades and
bolts in sets to preserve balance.
•On multibladed machines, take care as rotating one
blade can cause other blades to rotate.
Operation
•Do not operate the engine in a confined space where
dangerous carbon monoxide fumes can collect.
•Mow only in daylight or in good artificial light.
•Always be sure of your footing on slopes.
•Walk; never run.
•Keep a firm hold on the handle.
•For wheeled rotary machines, mow across the face of
slopes, never up and down.
•Exercise extreme caution when changing direction on
slopes.
•Do not mow excessively steep slopes.
•Use extreme caution when reversing or pulling the
mower toward you.
•Before and while moving backward, look behind and
down for small children.
•Stop the blade(s) if the mower has to be tilted for
transportation when crossing surfaces other than grass
and when transporting the mower to and from the area
to be mowed.
•Never operate the mower with damaged or missing
guards or shields, or without safety devices; for
example, deflectors and/or grass catchers in place.
•Do not change the engine governor settings or
overspeed the engine.
•Disengage all blade and drive clutches before starting
the engine.
•Start the engine or switch on the motor carefully
according to instructions and with feet well away from
the blade(s).
•Do not tilt when starting the engine or switching on
the motor, unless the mower has to be tilted for
starting. In this case, do not tilt it more than absolutely
necessary and lift only the part which is away from the
operator.
•Do not start the engine when standing in front of the
discharge chute.
•Do not put hands or feet near or under rotating parts.
Keep clear of the discharge opening at all times.
•Never pick up or carry a mower while the engine is
running.
•Stop the engine and disconnect the spark plug lead
– before clearing blockages or unclogging chute;
– before checking, cleaning, or working on the
mower;
– after striking a foreign object. Inspect the mower
for damage and make repairs before restarting and
operating the mower;
– if mower starts to vibrate abnormally (check
immediately).
•Stop the engine
– whenever you leave the mower;
– before refuelling.

5
•Reduce the throttle setting during engine run-out and,
if the engine is provided with a shut-off valve, turn the
fuel off at the conclusion of mowing.
•Stop the blade(s) when crossing gravel drives, walks,
or roads.
•Shut the engine off and wait until the blade comes to
complete stop before removing grass catcher.
•Do not operate the mower while under the influence of
alcohol or drugs.
•If the equipment should start to vibrate abnormally,
stop the engine and check immediately for the cause.
Vibration is generally a warning of trouble.
Slopes are a major factor related to slip and fall accidents
which can result in severe injury. All slopes require extra
caution feel uneasy on a slope, do not mow it.
•Watch for holes, ruts, or bumps. Tall grass can hide
obstacles.
•Do not mow near drop-offs, ditches, or embankments.
The operator could lose footing or balance.
•Do not mow on wet grass. Reduced footing could
cause slipping.
Maintenance and Storage
•Keep all nuts, bolts (especially blade attachment
bolts), and screws tight to be sure the equipment is in
safe working condition.
•Never store the equipment with gasoline in the tank
inside a building where fumes may reach an open
flame or spark.
•Allow the engine to cool before storing in any
enclosure.
•To reduce the fire hazard, keep the engine, muffler,
battery compartment, and gasoline storage area free of
grass, leaves, or excessive grease.
•Check the grass catcher frequently for wear or
deterioration.
•Replace worn or damaged parts for safety.
•Use extra care when handling gasoline; vapors are
explosive.
•Never tamper with safety devices. Check their proper
operation regularly.
•Keep the mower free of grass, leaves, or other debris
build-up. Clean up oil or fuel spillage.
•Stop and inspect the equipment if you strike an object.
Repair, if necessary, before restarting.
•Never attempt to make wheel height adjustments while
the engine is running.
•Always disconnect electric mowers (live operated)
before cleaning, repairing, or adjusting.
•Grass catcher components are subject to wear, damage,
and deterioration, which could expose moving parts or
allow objects to be thrown. Frequently check
components and replace with manufacturer’s
recommended parts when necessary.
•Mower blades are sharp and can cut. Wrap the blade(s)
or wear gloves, and use extra caution when servicing
them.
•Do not change the engine governor setting or
overspeed the engine.
•To ensure the best performance and safety, purchase
only genuine Lawn-Boy replacement parts and
accessories. Do not use “will fit” parts and
accessories; they may cause a safety hazard.

6
Safety and Instruction Decals
Safety decals and instructions are easily visible to the operator and are located near any
area of potential danger. Replace any decal that is damaged or lost.
By Front Height Adjuster
(Part No. 92-2914 Right)
(Part No. 92-2915 Left)
On Mower Housing
(Part No. 93-7250)
On Top of Grass Catcher Chute
(Part No. 92-2919)
(Model 10324)
On Mower Housing
(Part No. 43-8480)
On Mower Housing
(Part No. 99-6018)
Assembly
Note: Determine the left and right sides of the lawn mower by standing in the operating position.
Unfolding the Handle
WARNING
POTENTIAL HAZARD
•Folding or unfolding the handle improperly can
pinch, stretch, or damage one or more of the
cables.
WHAT CAN HAPPEN
•Any pinched, stretched, or damaged cable may
cause an operational failure that results in an
unsafe operating condition.
HOW TO AVOID THE HAZARD
•Do not pinch, stretch, or damage the cables.
•Handle the cables with care when folding or
unfolding the handle.
•Do not use the lawn mower if one or more of
the cables are pinched, stretched, or damaged.
Contact your Authorized Service Dealer.
1. Loosen the handle knobs and lift the upper handle
section in an arc until the upper and lower handle
sections line up and nest together (Fig. 2).
1068
21
3
Figure 2
1. Knobs
2. Upper handle section 3. Lower handle section
2. Tighten the knobs securely.
3. Rotate the handle toward the rear of the lawn mower
until it snaps into the stops in the handle brackets.
Note: The traction cable may disconnect during shipping
and prevent the lawn mower from self-propelling
(self-propel models only). If the traction cable is
disconnected, connect it (refer to Figure 16).

7
Adjusting the Handle Height
You can set the handle to two height settings: high and
low (Fig. 3). Select the handle height setting most
comfortable for you.
1026
1
2
3
4
Figure 3
1. Low setting
2. High setting 3. Cable anchor
(Self-propelled models)
4. Pin
1. Squeeze the bottom handle section (both sides) inward
off of the pins (Fig. 3).
2. Position the handle and the cable anchor
(self-propelled models only) over the pins at the
desired height.
Note: On self-propelled models, you may need to loosen
the belt cover and move it slightly.
3. On self-propelled models, adjust the cable. Refer to
Maintenance on page 12.
Before Starting
Mixing Gasoline and Oil
Your Lawn-Boy lawn mower is powered by a two-cycle
engine which requires a 32:1 mixture of gasoline and oil.
Use only clean, fresh, lead-free gasoline (including
oxygenated or reformulated gasoline) with an octane
rating of 87 or higher. To ensure freshness, purchase only
the amount of gasoline you expect to use in 30 days.
Using unleaded gasoline results in fewer combustion
chamber deposits and longer spark plug life.
IMPORTANT: Do not use methanol, gasoline
containing methanol, gasohol containing more than
10% ethanol, premium gasoline, or white gas. Using
these fuels can damage the engine’s fuel system.
IMPORTANT: Do not use automotive oil (i.e., SAE 30
or 10W30), a two-cycle oil that is not NMMA
TCW III-certified, or a fuel mixed at the wrong
gasoline/oil ratio. This can cause engine damage not
covered under the Lawn-Boy warranty.
DANGER
POTENTIAL HAZARD
•In certain conditions, gasoline is extremely
flammable and highly explosive.
WHAT CAN HAPPEN
•A fire or explosion from gasoline can burn you
and others and can damage property.
HOW TO AVOID THE HAZARD
•Fill the fuel tank outdoors, in an open area, and
when the engine is cold. Wipe up any gasoline
that spills.
•Do not fill the fuel tank completely full. Add
gasoline to the fuel tank until the level is 1/4 to
1/2 in. (6 to 13 mm) below the bottom of the
filler neck. This empty space in the tank allows
gasoline to expand.
•Never smoke when handling gasoline, and stay
away from an open flame or where a spark may
ignite the gasoline fumes.
•Store gasoline in an approved container and
keep it out of the reach of children.
•Never buy more than a 30-day supply of
gasoline.
DANGER
POTENTIAL HAZARD
•When fueling, under certain circumstances, a
static charge can develop, igniting the gasoline.
WHAT CAN HAPPEN
•A fire or explosion from gasoline can burn you
and others and cause property damage.
HOW TO AVOID THE HAZARD
•Always place gasoline containers on the ground
away from your vehicle before filling.
•Do not fill gasoline containers inside a vehicle
or on a truck or trailer bed because interior
carpets or plastic truck bed liners may insulate
the container and slow the loss of any static
charge.
•When practical, remove gas-powered
equipment from the truck or trailer and refuel
the equipment with its wheels on the ground.
•If this is not possible, refuel such equipment on
a truck or trailer from a portable container,
rather than from a gasoline dispenser nozzle.
•If a gasoline dispenser nozzle must be used,
keep the nozzle in contact with the rim of the
fuel tank or container opening at all times until
fueling is complete.
Use only Lawn-Boy Generation II 2-Cycle Oil (Fig. 4) or
an equivalent premium grade, NMMA TCW III-certified
two-cycle ashless oil.

8
Figure 4
Lawn-Boy Generation II 2-Cycle Oil is formulated
specifically for Lawn-Boy two-cycle engines and is
available from your Lawn-Boy retailer. Using Lawn-Boy
Generation II 2-Cycle Oil regularly will help keep your
engine clean, reduce spark plug fouling, piston ring
sticking, and pre-ignition. It also minimizes varnish
buildup, combustion chamber deposits, and exhaust port
blockage.
Substitute oils may produce more exhaust smoke, require
more frequent engine service, and reduce engine life.
Note: Failing to use the proper oil or the 32:1
gasoline-to-oil mixture ratio can result in serious engine
damage.
Add Lawn-Boy Generation II 2-Cycle Oil (Fig. 4) or an
equivalent oil to fresh, unleaded gasoline according to the
chart below:
32:1 Gasoline-to-Oil Ratio Mixing Chart
Gasoline Oil
1 gallon (3.8 liters) 4 ounces (118 ml)
2 gallons (7.6 liters) 8 ounces (237 ml)
5 gallons (19 liters) 20 ounces (591 ml)
To properly mix the gasoline and oil:
1. Pour half of the desired amount of fresh, unleaded
gasoline into a clean, approved gasoline container.
2. Add the full amount of Lawn-Boy Generation II
2-Cycle Oil (Fig. 4) or an equivalent oil to the
gasoline.
3. Install the cap on the gasoline container.
4. Shake the gasoline-and-oil mixture thoroughly.
5. Slowly remove the cap and add the remaining amount
of gasoline.
Note: Do not mix gasoline and oil in the fuel tank. Oil at
room temperature mixes easier and more thoroughly than
cold oil. Oil below 32°F (0°C) requires additional mixing.
111
123
Figure 5
1. Add oil to half of the
gasoline
2. Install the cap and shake
the can to mix
3. Add the remaining amount
of gasoline
IMPORTANT: Do not overfill the fuel tank. The
gasoline/oil mix must have room to expand.
IMPORTANT: Do not use fuel additives except a fuel
stabilizer during storage. Do not use fuel stabilizers
with an alcohol base such as ethanol, methanol, or
isopropanol. You do not need a stabilizer if you use
Lawn-Boy Generation II 2-Cycle Oil (Fig. 4).
6. Clean around the fuel cap (Fig. 6).
m–3833
1
2
Figure 6
1. Fuel cap 2. Primer
7. Remove the fuel cap and fill the fuel tank with the
gasoline-and-oil mixture to within 1/4 inch (6 mm)
from the top of the tank. Do not fill into the filler
neck.
8. Install the fuel cap securely and wipe up any spilled
fuel.

9
Operation
Starting the Engine
1. Ensure that the wire is connected to the spark plug
(Fig. 7).
m–3884
1
Figure 7
1. Spark plug wire
2. When starting a cold engine, move the throttle lever to
the Choke position (Fig. 8).
1019
1
Figure 8
1. Throttlelever
3. Push the primer three times (Fig. 6). Wait about two
seconds between each push.
Note: To start a warm engine, move the throttle level to
the Fast position and press the primer no more than once.
4. Hold the blade control bail against the upper handle
(Fig. 9).
982
1
3
2
Figure 9
1. Bladecontrol bail
2. Upper handle 3. Starter handle
5. Pull the starter handle lightly until you feel resistance,
then pull it sharply (Fig. 9). Let the rope return to the
handle slowly.
6. If the engine fails to start, repeat steps 3 through 5.
Stopping the Engine
1. Move throttle lever to the Slow position (Fig. 8).
2. Release the blade control bail (Fig. 10). Both the
engine and the blade will stop. Contact your
Authorized Service Dealer immediately if they do not.
1
1060 1060
Figure 10
1. Bladecontrol bail

10
Using the Self-propel Drive
Self-propel Models only
1. To operate the self-propel drive, squeeze the
self-propel drive bail against the handle and hold it
(Fig. 11).
1017
1
Figure 11
1. Self-propeldrive bail
Note: The maximum self-propel drive speed is fixed. To
reduce the speed, increase the space between the bail and
the handle.
2. To disengage the self-propel drive, release the
self-propel drive bail (Fig. 12).
1016
1
Figure 12
1. Self-propeldrive bail
Note: The lawn mower comes with free-wheeling clutches
which make it easier to pull the lawn mower rearward. To
disengage the clutches, you may need to push the lawn
mower forward one inch (2.5 cm) or more after you
release the self-propel drive bail.
Adjusting the Cutting Height
You can adjust each wheel individually with a wheel
height adjustment lever. Cutting heights are 1 in.
(25 mm); 1-1/2 in. (38 mm); 2 in. (51 mm); 2-1/2 in. (64
mm); 3 in. (76 mm); and 3-1/2 in. (89 mm).
DANGER
POTENTIAL HAZARD
•Adjusting the height-of-cut levers could bring
your hands into contact with a moving blade.
WHAT CAN HAPPEN
•Contact with a rotating blade can cause serious
injury.
HOW TO AVOID THE HAZARD
•Stop the engine and wait for all movement to
stop before adjusting the cutting height.
•Do not put fingers under the housing when
adjusting the cutting height.
1. Pull the adjusting lever toward the wheel and move it
to the desired position (Fig. 13).
1021
1
Figure 13
1. Wheelheight adjustment lever
2. Release the height adjust lever and seat it securely in
the desired notch.
Note: Set all four wheels to the same height.
Operating Tips
•Review the safety instructions and read this manual
carefully before operating the lawn mower.
•Clear the area of sticks, stones, wire, branches, and
other debris that the lawn mower could pick up or the
blade could hit and throw objects.
•Keep everyone, especially children and pets, away
from the area of operation.
•Avoid striking trees, walls, curbs, or other solid
objects. Never deliberately mow over any object.
•If the lawn mower strikes an object or starts to vibrate,
immediately stop the engine, disconnect the spark plug
wire, and examine the lawn mower for damage.
•Maintain a sharp blade throughout the cutting season.
Periodically file down nicks on the blade.
•Replace the blade when necessary with an original
Lawn-Boy replacement blade.
•Mow only dry grass or leaves. Wet grass and leaves
tend to clump on the yard and may cause the lawn
mower to plug or the engine to stall.

11
WARNING
POTENTIAL HAZARD
•Wet grass or leaves can cause you to slip and
contact the blade.
WHAT CAN HAPPEN
•Blade contact can seriously injure you.
HOW TO AVOID THE HAZARD
•Mow only in dry conditions.
•Clean clippings or leaves from the underside of the
lawn mower deck after each mowing. See Cleaning the
Lawn Mower Housing on page 13.
•Keep the engine in good running condition.
WARNING
POTENTIAL HAZARD
•Operating a lawn mower with its engine
running at a speed greater than the factory
setting can cause an unsafe operating condition.
WHAT CAN HAPPEN
•The lawn mower could throw a part of the
blade or engine into the operator’s or
bystander’s area and cause serious personal
injury or death.
HOW TO AVOID THE HAZARD
•Do not change the engine speed setting.
•If you suspect the engine speed is faster than
normal, contact your Authorized Service
Dealer.
•Clean the air filter frequently. Mulching stirs up more
clippings and dust which clogs the air filter and
reduces engine performance.
•To achieve the best mulching action, set the lawn
mower cutting height so that the lawn mower cuts no
more than a third of the grass stem or a maximum of
one-inch (25 mm) long clippings. If you try to mulch
more or if the grass is very lush, the mulching action
will be poor. Under these conditions, use the side
discharge or grass catcher. A few days later, install the
mulch plate on your lawn mower to resume mulching.
Cutting Grass
•In the summer heat, cut the grass at the 2, 2-1/2, or
3-inch (51, 64, or 76 mm) cutting height-settings. Only
cut off about one-third of the grass blade. Do not cut
below the two-inch setting unless the grass is sparse or
it is late autumn when the grass growth begins to slow
down.
•When cutting grass over six inches tall, first mow
using the highest cutting height setting and walking
slower; then mow again at a lower setting for best
lawn appearance. If the grass is too long and leaves
clumps on top of the lawn, the lawn mower may plug
up and cause the engine to stall.
•Alternate the mowing direction. This helps disperse
the clippings over the lawn for even fertilization.
If the finished cut lawn appearance is unsatisfactory, try
one or more of the following:
•Sharpen the blade.
•Walk at a slower pace while mowing.
•Raise the cutting height on your lawn mower.
•Cut the grass more frequently.
•Overlap the cutting swaths instead of cutting a full
swath with each pass.
•Set the cutting height on the front wheels one notch
lower than the rear wheels.
Cutting Leaves
•After cutting the lawn, make sure that half of the lawn
shows through the cut leaf cover. You may need to
make one or more passes over the leaves.
•For light leaf coverage, set all the wheels at the same
cutting height.
•If there are more than 5 inches (12.7 cm) of leaves on
the lawn, set the front wheels one or two notches
higher than the rear wheels. This makes it easier to
feed the leaves under the lawn mower deck.
•Slow down your mowing speed if the lawn mower
does not cut the leaves finely enough.
•If you mow over oak leaves, you can add lime to the
grass in the spring to reduce the acidity of the leaves.

12
Maintenance
NOTICE:To obtain repairs at no charge under the terms and provisions of the Lawn-Boy warranty statement, an
Authorized Service Dealer must perform the service or emission control part repair or replacement.
Recommended Maintenance Schedule
Service Item Service Operation Each
Use 25 Hours 50 Hours 100 Hours
Blade Brake
Check the stopping time before each use. The
blade must stop within three seconds of releasing
the bail; if it does not, contact your Authorized
Service Dealer for repair.
X
Housing Clean off built-up grass clippings and dirt from the
housing after each use. X
Fasteners Check the blade and the engine mounting fasteners. Keep all nuts, bolts, and screws tight to
ensure safe operation. X
Self-
p
ro
p
el Drive
Clean the grass clippings and debris under the
belt cover and near the drive belt (self-propelled
models). X
S
e
lf
-prope
l
D
r
i
ve Grease the rear height adjustor brackets
(self-propel models). X
Adjust the self-propel drive after changing the
handle height, installing a new self-propel drive
cable, or if the traction drive belt slips. X
Air Filter Remove and clean the air filter each mowing season or every 50 hours. Clean the air filter
more frequently in dusty operating conditions. X
Spark Plug Clean, inspect, and gap the spark plug. Replace it
if necessary. X
Blade Sharpen or replace the blade; maintain the blade more frequently if the edge dulls quickly in rough
or sandy conditions. X
Fuel System Check the fuel system for leaks and/or a deteriorating fuel hose. Replace parts if
necessary. X
Exhaust Port Clean the exhaust port. X
Cooling System
Clean off grass clippings, debris, or dirt that can
clog the engine air cooling fins and starter. Clean
the cooling system more frequently in dirty
operating conditions.
X

13
CAUTION
POTENTIAL HAZARD
•If you leave the wire on the spark plug, someone could start the engine.
WHAT CAN HAPPEN
•Someone accidentally starting the engine could seriously injure you or other bystanders.
HOW TO AVOID THE HAZARD
•Disconnect the wire from the spark plug before you do any maintenance. Set the wire aside
so it does not accidentally contact spark plug.
Cleaning the Lawn Mower
Housing
A clean lawn mower housing provides the best cutting
performance. Check for grass buildup and clean it after
each use.
Washing Method
1. Move the lawn mower to a flat concrete or asphalt
surface near a garden hose.
2. Start the engine.
3. Hold the running garden hose at handle level and
direct the water to flow on the ground just in front of
the right rear tire (Fig. 14).
1093
1
Figure 14
1. Rear right wheel
The blade will draw in water and wash out clippings.
Let the water run until the clippings no longer come
out from under the housing.
4. Stop the engine and wait for all moving parts to stop.
5. Turn off the garden hose.
6. Start the lawn mower and let it run for a few minutes
to dry out the moisture on the lawn mower and its
components.
7. While the engine runs, engage and disengage the
traction drive several times to dry it out.
Scraping Method
If washing does not remove all debris from under the lawn
mower, tip it and scrape it clean.
1. Run the engine dry or remove the fuel when the engine
is cool.
WARNING
POTENTIAL HAZARD
•Gasoline is extremely flammable, highly
explosive and under certain conditions can
cause personal injury or property damage.
WHAT CAN HAPPEN
•Tipping the lawn mower may cause fuel leakage
from carburetor or fuel tank.
HOW TO AVOID THE HAZARD
•Avoid fuel spills by running the engine dry or
removing the gasoline with a hand pump; never
siphon.
2. Disconnect the wire from the spark plug (Fig. 7).
3. Tip the lawn mower onto its right side (Fig. 15).
1036
Figure 15
Note: When you tip the lawn mower onto its side, rotate
the blade as little as possible to avoid starting problems.
4. Scrape the built-up grass clippings and dirt from the
lawn mower housing with a hardwood scraper.
5. Tip the lawn mower upright.
6. Connect the wire to the spark plug.

14
Cleaning the Self-propel Drive
Self-propel Models only
Under certain conditions, the clippings can collect under
the belt drive cover and in the pulley groove. This can
cause the belt to slip, the self-propel drive to lose power,
or the self-propel drive not to disengage.
Clean the grass clippings and debris from under the belt
cover every 25 hours of operation.
1. Remove the screw from the belt cover (Fig. 16).
m–4461
1
3
2
4
Figure 16
1. Belt cover
2. Screw 3. Cable spring 4. Drive bracket
2. Unhook the cable spring from the drive bracket
(Fig. 16).
3. Remove the belt cover by pulling it straight out from
the engine.
Note: If the belt cover is pinched between the handle and
handle bracket, remove the handle before removing the
belt cover. For more information, refer to Adjusting the
Handle Height on page 7.
4. Remove the debris from under the cover and the pulley
groove.
5. Replace the belt cover by squeezing the sides together
and inserting the tabs on the belt cover into the
brackets on the engine base (Fig. 17).
m–4472
1
3
2
32
Figure 17
1. Belt cover
2. Tab 3. Bracket
6. Secure the belt cover with the screw.
7. Hook the cable spring onto the drive bracket.
Lubricating the Self-propel
Drive
Self-propel Models only
1. Wipe the grease fittings on the rear height-of-cut
adjustors (Fig. 18) with a clean rag.
1018
1
Figure 18
1. Grease fittings
2. Install a grease gun onto each fitting and gently apply
one or two pumps of #2 multi-purpose lithium grease
to each.
IMPORTANT: Excess grease may prevent the wheel
clutch from properly operating.
Adjusting the Self-propel Drive
Cable
Self-propel Models only
Whenever you change the handle height, install a new
self-propel drive cable, or if the traction drive belt slips,
adjust the self-propel drive cable.
Adjust the self-propel drive cable on the handle by
moving the cable jacket held by the cable support.
1. Loosen the nut on the cable support (Fig. 19).
1063
1
23
4
5
Figure 19
1. 1 to 1/in. (25 to 38 mm)
2. Self-propel drive bail
3. Cable jacket
4. Cable support
5. Nut

15
2. Hold the self-propel drive bail 1 to 1-1/2 in. (25 to
38 mm) from the handle (Fig. 19).
3. Pull the cable jacket down (away from the bail) to
remove the slack in the cable between the bail and the
cable support.
4. Tighten the nut on the cable support.
5. Release the bail and ensure that the cable is loose.
Note: The cable must be loose when you release the bail
or the lawn mower may creep when you disengage the
bail.
Servicing the Air Filter
Clean the air filter once every season or every 50 hours;
clean it more frequently under dusty conditions.
Note: Do not operate the engine without the air filter
element; extreme engine damage will occur.
1. Snap the air filter cover latch open and swing it to the
side (Fig. 20).
ÎÎÎÎ
ÎÎÎÎ
ÎÎÎÎ
ÎÎÎÎ
m–3834
1
2
Figure 20
1. Filter 2. Cover
2. Remove the air filter.
3. Wash the air filter in laundry detergent or kerosene
(Fig. 21).
988
Figure 21
4. Squeeze the filter to remove excess liquid and blot it
dry with a paper towel or rag.
5. Saturate the air filter with SAE 30W oil (Fig. 22).
989
Figure 22
6. Squeeze the filter to distribute the oil evenly. Blot the
filter lightly with a paper towel to remove excess oil.
7. Replace the filter with the cleanest side facing the
carburetor.
Note: Ensure that the filter fully seats in the air box and
does not pucker, allowing air and dirt to pass directly
through to the carburetor.
Maintaining the Spark Plug
A spark plug that is dirty, pitted, carbon-covered, or has
worn electrodes may cause hard starting and poor
operation.
Clean or replace the spark plug once a season or every 50
hours, whichever occurs first. Use an NGK BPMR4A
spark plug.
1. Disconnect the wire from the spark plug (Fig. 7).
2. Remove the spark plug and clean it with a wire brush,
removing carbon buildup.
IMPORTANT: Do not sandblast the spark plug.
3. Check the condition of the plug for cracks and
damaged or worn electrodes. Replace it if necessary.
4. Set the spark plug gap at 0.035 in. (0.9 mm) (Fig. 23).
986
1
Figure 23
1. 0.035in. (0.9 mm)
5. Install the spark plug by hand, then torque it to
180 in-lb (15 ft-lb or 20 N⋅m).
6. Connect the wire to the spark plug.

16
Maintaining the Blade
A straight, sharp blade provides maximum cutting
performance. Regularly inspect and sharpen the blade.
WARNING
POTENTIAL HAZARD
•The blade is sharp.
WHAT CAN HAPPEN
•Contact with the sharp blade can cause serious
personal injury.
HOW TO AVOID THE HAZARD
•Wear gloves or wrap the sharp edges of the
blade with a rag.
1. Disconnect the wire from the spark plug (Fig. 7).
2. Tip the lawn mower onto its right side (Fig. 15).
Inspecting the Blade
Carefully examine the blade for sharpness and wear,
especially where the flat and the curved parts meet
(Fig. 24A). Because sand and abrasive material can wear
away the metal that connects the flat and curved parts of
the blade, check the blade before using the lawn mower. If
you notice a slot or wear (Figs. 24B and 24C), replace the
blade; refer to Removing the Blade on page 16.
270
1
1
1
2
3
4
A
B
C
Figure 24
1. Sail
2. Flat part of blade 3. Wear 4. Slot formed
Note: For the best performance, install a new blade before
the cutting season begins. During the year, file down any
small nicks to maintain the cutting edge.
DANGER
POTENTIAL HAZARD
•A worn or damaged blade could break and a
piece of the blade could be thrown into the
operator’s or bystander’s area.
WHAT CAN HAPPEN
•A thrown piece of the blade could cause serious
personal injury or death to the operator or
bystanders.
HOW TO AVOID THE HAZARD
•Inspect the blade periodically for wear or
damage.
•Replace a worn or damaged blade.
Removing the Blade
1. Remove the blade nut and the mulching fan (Fig. 25).
4
23
1
M–2909
Figure 25
1. Bladenut
2. Mulching fan 3. Blade 4. Blade driver
2. Remove the blade from the blade driver (Fig. 25).
3. Examine the mulch fan for worn or bent blades.
Replace it if necessary.
4. Examine the blade driver for bent or sheared drive
lugs. Replace it if necessary.
Sharpening the Blade
File the top side of the blade to maintain its original
cutting angle (Fig. 26A) and inner cutting edge radius
(Fig. 26B).
153
1
m4783
2
AB
Figure 26
1. Sharpenat this angle only 2. Maintain the original
radius here
Note: The blade will remain balanced if you remove the
same amount of material from both cutting edges.

17
Note: Do not grind the blade more than 5 in. (127 mm)
from the outside ends and no less than 2 in. (51 mm) from
the trailing edge (Fig. 27).
990
2”
(51 mm)
5”
(127 mm)
Figure 27
Balancing the Blade
1. Check the balance of the blade by placing the center
hole of the blade over a nail or a screwdriver shank
clamped horizontally in a vise (Fig. 28).
1007
Figure 28
Note: You can also check the balance by using a
commercially manufactured blade balancer.
2. If either end of the blade rotates downward, file that
end (not the cutting edge or the end near the cutting
edge). The blade is properly balanced when neither
end drops.
Installing the Blade
1. Ensure that the blade driver is installed on the
crankshaft. See Figure 25.
2. Install the blade over the lugs of the blade driver with
the curved ends toward the housing (Fig. 25).
3. Install the mulch fan into the blade recess (Fig. 25).
4. Secure the blade with the blade nut (Fig. 25).
5. Torque the blade nut to 47 ft-lb (63 Nm).
Note: Replace the blade nut after installing and removing
the blade four times. The blade nut’s locking power
diminishes and the blade nut could loosen if you do not
replace it.
6. Connect the wire to the spark plug.
Cleaning the Exhaust Port
Carbon deposit build-up causes excessive wear and loss of
power. Check and clean the exhaust port every 100 hours.
1. Disconnect the wire from the spark plug (Fig. 7).
2. Drain the fuel from the fuel tank.
3. Tip the lawn mower onto its right side.
WARNING
POTENTIAL HAZARD
•Gasoline is extremely flammable, highly
explosive and under certain conditions can
cause personal injury or property damage.
WHAT CAN HAPPEN
•Tipping the lawn mower may cause fuel leakage
from the carburetor or fuel tank.
HOW TO AVOID THE HAZARD
•Avoid fuel spills by running the engine dry or
removing the gas with hand pump; never
siphon.
4. Remove the blade nut, mulch fan, and blade. Refer to
Removing the Blade on page 16.
5. Remove the four capscrews that attach the cover plate
to the engine mounting plate (Fig. 29).
m–3836
1
3
2
4
5
Figure 29
1. Cover plate
2. Cap screw
3. Transfer pipe
4. Exhaust port
5. High temperature silicone
sealant
6. Remove the transfer pipe (Fig. 29).
7. Inspect the transfer pipe and clean it if it is dirty.
8. Rotate the crankshaft slowly until the piston covers the
exhaust port (Fig. 29).
9. Using a wooden dowel, loosen the carbon deposits by
inserting the dowel into the exhaust port.
Note: Do not use metal tools; they can scratch the piston.

18
10.Set the lawn mower upright.
11. Hold the blade control bail against the upper handle
(Fig. 30) and pull the starter rope several times to blow
out any loose carbon.
982
1
32
Figure 30
1. Bladecontrol bail
2. Upper handle 3. Starter handle
12.Wipe the bottom of the cover plate and the edge of the
engine mounting plate where the sealant will go with a
clean cloth to remove any dirt (Fig. 29).
13.Run a bead of high-temperature automotive silicone
sealant along the edge of the engine mounting plate
where the cover plate will rest (Fig. 29).
14.Install the transfer pipe and cover plate (Fig. 29),
torquing the four cap screws to 75 in-lb (8.5 N·m).
15.Install the blade driver, blade, and mulch fan with the
blade nut. Refer to the Installing the Blade on page 17.
16.Torque the blade nut to 560 in-lb (47 ft-lb or 63 N·m).
17.Tip the lawn mower upright.
18.Connect the wire to the spark plug.
Storage
To prepare the lawn mower for off-season storage,
perform the recommended maintenance procedures.
Refer to Maintenance on page 12.
Store the lawn mower in a cool, dry place. Cover the lawn
mower to keep it clean and protected.
Preparing the Fuel System
WARNING
POTENTIAL HAZARD
•Gasoline can vaporize if you store it over long
periods of time.
WHAT CAN HAPPEN
•Vaporized gasoline can explode if it comes into
contact with an open flame.
HOW TO AVOID THE HAZARD
•Do not store gasoline over long periods of time.
•Do not store the lawn mower with gasoline in
the fuel tank or the carburetor in an enclosure
with an open flame. (For example, a furnace or
a water heater pilot light.)
•Allow the engine to cool before storing it in any
enclosure.
1. Empty the fuel tank using a hand-type siphon only.
2. Run the lawn mower until the engine stops from
running out of fuel.
3. Prime the engine and start it again.
4. Allow the engine to run until it stops. When you can
no longer start the engine, it is sufficiently dry.
Preparing the Engine
1. Remove the spark plug.
2. Using an oil can, add about one tablespoon of oil to
the engine through the spark plug hole (Fig. 31).
1009
Figure 31
3. Slowly rotate the engine several times, using the
starter rope, to distribute the oil.
4. Install the spark plug but do not connect the wire to
the spark plug.
General Information
1. Clean the lawn mower housing. Refer to Cleaning the
Lawn Mower Housing on page 13.

19
2. Clean any dirt and chaff from the cylinder, cylinder
head fins, and blower housing.
3. Remove grass clippings, dirt, and grime from the
external parts of the engine, the shrouding, and the top
of the lawn mower housing.
4. Check the condition of the blade. Refer to Maintaining
the Blade on page 16.
5. Tighten all nuts, bolts, and screws.
6. Lubricate the wheels. Refer to Lubricating the
Self-propel Drive on page 14.
7. Touch up all rusted or chipped paint surfaces with
paint available from an Authorized Service Dealer.
Folding the Handle
WARNING
POTENTIAL HAZARD
•Folding or unfolding the handle improperly can
pinch, stretch, or damage one or more of the
cables.
WHAT CAN HAPPEN
•Any pinched, stretched, or damaged cable may
cause an operational failure that results in an
unsafe operating condition.
HOW TO AVOID THE HAZARD
•Do not pinch, stretch, or damage the cables.
•Handle the cables with care when folding or
unfolding the handle.
•Do not use the lawn mower if one or more of
the cables are pinched, stretched, or damaged.
Contact your Authorized Service Dealer.
1. Squeeze the bottom handle sections together and slide
them past the stops on the handle brackets (Fig. 32).
1039
Figure 32
2. Rotate the handle toward the front of the lawn mower
(Fig. 33).
1068
Figure 33
3. Loosen the knobs that secure the upper handle section
to the bottom section and fold the top handle section
back toward the rear of the lawn mower into the
storage position (Fig. 33).
Removing from Storage
1. Carefully unfold the handle. Refer to Unfolding the
Handle on page 6.
2. Check and tighten all fasteners.
3. Remove the spark plug and spin the engine rapidly
using the starter to blow excess oil from the cylinder.
4. Clean the spark plug or replace it if it is cracked,
broken, or if the electrodes are worn.
5. Install the spark plug and torque it to 180 in-lb
(15 ft-lb or 20 Nm).
6. Perform the recommended maintenance procedures.
Refer to Maintenance on page 12.
7. Fill the fuel tank with a fresh, clean gasoline/oil mix.
8. Connect the wire to the spark plug (Fig. 7).
Accessories
Your lawn mower may include accessories available from
your Authorized Service Dealer. For proper installation of
these accessories, follow these instructions.
Installing a Rear Grass Catcher
Models 10247, 10323, and 10324 only
1. Stop the engine and wait for all moving parts to stop.
2. Disconnect the wire from the spark plug (Fig. 7).
3. Remove the wing screw that fastens the cover plate to
the housing (Fig. 34).

20
996
1
2
Figure 34
1. Cover or mulch plate 2. Wing screw
4. Slide the cover plate counterclockwise and remove it
from the lawn mower housing.
5. Place the front corner of the chute baffle into the deck
opening.
6. Rotate the chute counterclockwise and push it down
into the deck opening (Fig. 35).
1073
1
23
Figure 35
1. Chutebaffle
2. Deck baffle 3. Toe guard
Note: The chute baffle must go behind the front deck
baffle and between the blade and toe guard to prevent it
from contacting the blade.
7. Insert the chute support rod through the hole in the
right side of the deck (Fig. 36).
1014
1
Figure 36
1. Chute support rod
8. Push the key hole slots on the chute down over the two
shoulder bolts on the lawn mower housing, and slide
the chute clockwise to lock it in place.
9. Secure the chute assembly with the wing screw
(Fig. 37).
1013
2
1
Figure 37
1. Chute assembly 2. Wing screw
10.Check the clearance between the blade tips and the
baffle, ensuring that there is no contact (Fig. 38).
Note: The baffle must go behind the front deck baffle and
between the blade and toe guard to prevent contact with
the blade (Fig. 38).