Lawn-Boy Euro Series User manual

Operator’s Manual
IMPORTANT: Read this manual carefully. It contains information about your
safety and the safety of others. Also become familiar with the controls and
their proper use before you operate the product.
Operator’s Manual
IMPORTANT: Read this manual carefully. It contains information about your
safety and the safety of others. Also become familiar with the controls and
their proper use before you operate the product.
FORM NO. 3319–114GB
Euro-Series
Walk-Behind
Power Mower
Model No. 10800 – 7900001 & Up

Lawn-Boy Inc. – 1997
Printed in USA All Rights Reserved
Introduction
Thank you for purchasing a Lawn-Boy product.
All of us at Lawn-Boy want you to be completely
satisfied with your new product, so feel free to
contact your local Authorized Service Dealer for help
with service, genuine Lawn-Boy parts, or other
information you may require.
Whenever you contact your Authorized Service
Dealer or the factory, always know the model and
serial numbers of your product. These numbers will
help the Service Dealer or Service Representative
provide exact information about your specific
product. You will find the model and serial number
decal located in a unique place on the product as
shown below .
1064

1. Model and Serial Number
Decal
For your convenience, write the product model and
serial numbers in the space below.
Model No:
Serial No.
Read this manual carefully to learn how to operate
and maintain your product correctly. Reading this
manual will help you and others avoid personal injury
and damage to the product. Although Lawn-Boy
designs, produces and markets safe, state-of-the-art
products, you are responsible for using the product
properly and safely. You are also responsible for
training persons who you allow to use the product
about safe operation.
The Lawn-Boy warning system in this manual
identifies potential hazards and has special safety
messages that help you and others avoid personal
injury, even death. DANGER, W
ARNING and
CAUTION are signal words used to identify the level
of hazard. However, regardless of the hazard, be
extremely careful.
DANGER signals an extreme hazard that will cause
serious injury or death if the recommended
precautions are not followed.
WARNING signals a hazard that may cause serious
injury or death if the recommended precautions are
not followed.
CAUTION signals a hazard that may cause minor or
moderate injury if the recommended precautions are
not followed.
Two other words are also used to highlight
information. “Important” calls attention to special
mechanical information and “Note” emphasizes
general information worthy of special attention.
The left and right side of the machine is determined
by standing behind the handle in the normal
operator’s position.

GB–1
Contents
Page
Safety 2.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Symbol Glossary 4 . . . . . . . . . . . . . . . . . . . .
Assembly 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Handle 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cover Plate 7 . . . . . . . . . . . . . . . . . . . . . . . . .
Before Starting 9 . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil Mix Ratio 9 . . . . . . . . . . . . . . . . . . . . . . .
Mixing Gasoline And Oil 10 . . . . . . . . . . . . . .
Lawn Preparation And Mowing 11 . . . . . . . . .
Operation 12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starting Engine 12 . . . . . . . . . . . . . . . . . . . . . .
Stopping Engine 12 . . . . . . . . . . . . . . . . . . . . .
Adjusting Cutting Height 13 . . . . . . . . . . . . . .
Mulching Tips 14 . . . . . . . . . . . . . . . . . . . . . .
Page
Maintenance 15 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended Maintenance Schedule 15 . . .
Air Filter 16 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Spark Plug 17 . . . . . . . . . . . . . . . . . . . . . . . . .
Clean Mower Housing 17 . . . . . . . . . . . . . . . .
Blade 18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust Ports 20 . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting 22 . . . . . . . . . . . . . . . . . . . . . . . . .
Accessories 23 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Grass Catcher 23 . . . . . . . . . . . . . . . . . . .
Mulch Plate 26 . . . . . . . . . . . . . . . . . . . . . . . .
Storage 28 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel 28 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine 29 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Folding Handle 29 . . . . . . . . . . . . . . . . . . . . . .
Removing From Storage 30 . . . . . . . . . . . . . .

GB–2
Safety
Training
1. Read the instructions carefully. Be familiar with
the controls and the proper use of the equipment.
2. Never allow children or people unfamiliar with
these instructions to use the lawnmower. Local
regulations may restrict the age of the operator.
3. Never mow while people, especially children, or
pets are nearby.
4. Keep in mind that the operator or user is
responsible for accidents or hazards occurring to
other people or their property.
Preparation
1. While mowing, always wear substantial
footwear and long trousers. Do not operate the
equipment when barefoot or wearing open
sandals.
2. Thoroughly inspect the area where the
equipment is to be used and remove all objects
which may be thrown by the machine.
3. WARNING – Petrol is highly flammable.
•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
petrol while the engine is running or when
the engine is hot.
•If petrol 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 petrol vapors
have dissipated.
•Replace all fuel tanks and container caps
securely.
4. Replace faulty silencers.
5. 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.
6. On multi–bladed machines, take care as rotating
one blade can cause other blades to rotate.
Operation
1. Do not operate the engine in a confined space
where dangerous carbon monoxide fumes can
collect.
2. Mow only in daylight or in good artificial light.
3. Avoid operating the equipment in wet grass,
where feasible.
4. Always be sure of your footing on slopes.
5. Walk, never run.
6. For wheeled rotary machines, mow across the
face of slopes, never up and down.
7. Exercise extreme caution when changing
direction on slopes.
8.
Do not mow excessively steep slopes.
9. Use extreme caution when reversing or pulling
the lawnmower towards you.
10. Stop the blade(s) if the lawnmower has to be
tilted for transportation when crossing surfaces
other than grass, and when transporting the
lawnmower to and from the area to be mowed.
11. Never operate the lawnmower with defective
guards or shields, or without safety devices, for
example deflectors and/or grass catchers, in
place.

Safety
GB–3
12. Do not change the engine governor settings or
overspeed the engine.
13. Disengage all blade and drive clutches before
starting the engine.
14. Start the engine or switch on the motor carefully
according to instructions and with feet well away
from the blade(s).
15. Do not tilt the lawnmower when starting the
engine or switching on the motor, except if the
lawnmower 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.
16. Do not start the engine when standing in front of
the discharge chute.
17. Do not put hands or feet near or under rotating
parts. Keep clear of the discharge opening at all
times.
18. Never pick up or carry a lawnmower while the
engine is running.
19. Stop the engine and disconnect the spark plug
wire
•before clearing blockages or unclogging
chute;
•before checking, cleaning or working on the
lawnmower;
•after striking a foreign object. Inspect the
lawnmower for damage and make repairs
before restarting and operating the
lawnmower;
•if lawnmower starts to vibrate abnormally
(check immediately).
20. Stop the engine
•whenever you leave the lawnmower;
•before refuelling.
21. Reduce the throttle setting during engine shut
down and, if the engine is provided with a
shut-off valve, turn the fuel off at the conclusion
of mowing.
22. Go slow when using a trailing seat.
Maintenance and storage
1. Keep all nuts, bolts and screws tight to be sure
the equipment is in safe working condition.
2. Never store the equipment with petrol in the tank
inside a building where fumes may reach an
open flame or spark.
3. Allow the engine to cool before storing in any
enclosure.
4. To reduce the fire hazard, keep the engine,
silencer, battery compartment and petrol storage
area free of grass, leaves, or excessive grease.
5. Check the grass catcher frequently for wear or
deterioration.
6. Replace worn or damaged parts for safety.
7. If the fuel tank has to be drained, this should be
done outdoors.
Sound Pressure Level
This unit has an equivalent continuous A-weighted
sound pressure at the operator ear of: 87 dB(A), based
on measurements of identical machines per ANSI
B71.5-1984 procedures.
Sound Power Level
This unit has a sound power level of: 96 dB(A)/1 pW,
based on measurements of identical machines per
Directive 84/538/EEC and amendments.
Vibration Level
This unit has a maximum hand-arm vibration level of
10.51 m/s@, based on measurement of identical
machines per ISO 5349.

Safety
GB–4
Symbol Glossary
Safety alert triangle —
symbol within triangle
indicates a hazard.
Do not open or
remove safety shields
while engine is
running.
Safety alert symbol
Rotating blade can cut
off toes or fingers.
Stay clear of mower
blade as long as
engine is running.
Read operator ’s
manual.
To avoid blade failure
when mulching, use
blade stiffener when
mower is equipped
with mulching plug.
Consult technical
manual for proper
service procedures.
Transmission
Stay a safe distance
from the machine.
Oil
Stay a safe distance
from the mower .On/Run
Thrown or flying
objects — Whole body
exposure Engage
Thrown or flying
objects — Rotary
side-mounted mower .
Keep deflector shield
in place.
Disengage

Safety
GB–5
Stop engine before
leaving operator
position.
Battery charging
condition
Hourmeter/elapsed
operating hours Fuel
Fast Neutral
Slow First gear
Decreasing/Increasing Second gear
Grease lubrication
point
Third gear
Engine start
Cutting element —
basic symbol
Engine stop
Cutting element —
height adjustment
Choke Pull rope.

Safety
GB–6
Primer (start aid) Wheel
Push primer three
times.
Wheel traction
Properly dispose of
batteries.
Lower control bar .
Insert key into ignition
switch.
Raise control bar .
Turn key in ignition
switch.
Raise/lower control
bar.
Move control.
Raise/lower control
bar.
Move control forward. Raise control bar .
Move control
rearward.
Raise control bar .
Lower control bar .

GB–7
Assembly
Handle
Assembly
1. Loosen handle knobs and lift top handle half in
an arc until handle halves are in line and nest
together (Fig. 1).
Note: Use care to prevent pinching or
stretching of cables.
21
1300
Figure 1
1. Knob 2. Top handle half
2. Tighten knobs securely.
Note: Rotate handle toward rear of mower
until it snaps into stops in handle
brackets.
Handle Height
The handle two height positions — high and low
(Fig. 2). Select a handle height position that is most
comfortable for you.
1. To change handle height, squeeze bottom handle
section together and align holes over pins inside
handle brackets.
1199
1
2
Figure 2
1. Low setting 2. High setting
Cover Plate and Guard Plate
Your mower was shipped with a cover plate and
guard plate. For side discharge operation the cover
plate must be installed in the deck opening and the
guard plate over the side discharge opening.
POTENTIAL HAZARD
•An uncovered discharge opening will allow
objects to be thrown in operator’
s or
bystander’s direction. Also, contact with
blade could occur.
WHAT CAN HAPPEN
•Thrown objects or blade contact can cause
serious injury .
HOW TO AV
OID THE HAZARD
•Never operate mower unless cover plate,
guard plate, mulch plate or grass chute and
catcher are installed.

Assembly
GB–8
1. Stop engine and disconnect spark plug wire
(Fig. 3) before installing or removing cover
plate.
1042
1
Figure 3
1. Spark plug wire
2. Remove bolt that fastens cover plate to the
housing (Fig. 4).
1754
1
2
Figure 4
1. Cover plate 2. Bolt
3. Two shoulder bolts on the housing protrude
through slotted holes in the cover plate and do
not have to be loosened or removed. Cover plate
moves over the shoulder bolt heads (Fig. 5).
995
1
Figure 5
1. Shoulder bolt
4. Slide cover plate clockwise to install or
counterclockwise to remove.
5. Secure with bolt.
6. Install guard plate over side discharge opening
(Fig. 6).
1756
1
2
Figure 6
1. Guard plate 2. Bolt and nut
7. Secure with two bolts and nuts.
8. Connect spark plug wire (Fig. 3).

GB–9
Before Starting
Oil Mix Ratio
Your Lawn-Boy mower is powered by a 2-cycle
engine which requires a mixture of gasoline and oil;
32:1 with Lawn–Boyr 2-CYCLE ASHLESS OIL.
Failure to use the right mixture will result in serious
engine damage.
Use Lawn-Boy 2-CYCLE ASHLESS OIL (Fig. 7),
which is formulated specifically for Lawn-Boy and is
available from your Lawn-Boy retailer. Regular use
of Lawn-Boy 2-CYCLE ASHLESS OIL will help
keep your engine clean, reduce spark plug fouling,
piston ring sticking and pre-ignition. Lawn-Boy
2-CYCLE ASHLESS OIL will also minimize varnish
build-up, combustion chamber deposits and exhaust
port blockage.
1057
Figure 7
If Lawn-Boy 2-CYCLE ASHLESS OIL is not
available, other premium grade 2-CYCLE ASHLESS
OILS can be substituted. Substitute oils may produce
more exhaust smoke and may require increased
engine service including more frequent spark plug
changes, exhaust port/cylinder decarbonizing and
could reduce engine life.
Note: NEVER USE AUTOMOTIVE OIL
(i.e. SAE 30, 10W30 etc.), OR THE
WRONG MIX RA TIO BECAUSE
ENGINE DAMAGE MAY OCCUR. If
engine failure occurs and it has been
determined that Lawn-Boy 2-CYCLE
ASHLESS OIL was not used, the
failure may not be covered by the
Lawn-Boy warranty.
POTENTIAL HAZARD
•In certain conditions gasoline is extremely
flammable and highly explosive.
WHAT CAN HAPPEN
•A fire or explosion from gasoline can burn
you, others, and cause property damage.
HOW TO AV
OID THE HAZARD
•Use a funnel and fill the fuel tank outdoors,
in an open area, 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” (6 mm 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
gasoline fumes may be ignited by a spark.
•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.

Before Starting
GB–10
Mixing Gasoline And Oil
For simplicity and best engine performance, mix
8 ounces of Lawn–Boy 2–CYCLE ASHLESS OIL
with two gallons of fresh, unleaded regular gasoline.
Pour one gallon of gasoline into an approved gasoline
container and add the correct amount of 2-cycle oil.
Install cap on gasoline container and shake to mix oil
and gasoline thoroughly (Fig. 8). Slowly remove cap
and add remaining gasoline.
1056
Figure 8
Note: Do not mix gasoline and oil in the
product fuel tank. Oil that is at room
temperature mixes easily and more
thoroughly than cold oil.
Use clean, fresh lead-free gasoline with an octane
rating of 85 or higher. Purchase only the quantity of
gasoline that can be used in 30 days to assure
freshness. Use of lead-free gasoline results in fewer
combustion chamber deposits and longer spark plug
life. Leaded gasoline may be used if lead-free is not
available.
Note: NEVER USE METHANOL,
GASOLINE CONTAINING
METHANOL, GASOHOL
CONTAINING MORE THAN 10%
ETHANOL, PREMIUM GASOLINE
OR WHITE GAS BECAUSE
ENGINE FUEL SYSTEM COULD
BE DAMAGED.
1. Clean around fuel cap before removing (Fig. 9).
Fill fuel tank with gasoline/oil mix to bottom of
filler neck, not into filler neck. DO NOT
OVER-FILL TANK. Replace fuel cap securely
and wipe up any spilled fuel.
1044
1
Figure 9
1. Fuel tank cap
Lawn–Boy recommends that Lawn–Boy 2+4rFuel
Conditioner (Fig. 10) be used regularly during
operation and storage. Lawn–Boy 2+4rFuel
Conditioner cleans the engine during operation and
prevents gum–like varnish deposits from forming in
the engine during storage.
1058
Figure 10

Before Starting
GB–11
DO NOT USE FUEL ADDITIVES OTHER
THAN THOSE MANUF ACTURED FOR FUEL
STABILIZA TION DURING ST ORAGE, SUCH
AS LAWN-BOY 2+4r FUEL CONDITIONER.
LA WN-BOY DOES NOT RECOMMEND
ST ABILIZERS WITH AN ALCOHOL BASE
SUCH AS ETHANOL OR METHANOL.
ST ABILIZERS SHOULD NOT BE USED T O
TRY TO ENHANCE THE POWER OR
PERFORMANCE OF MACHINE.
2. Connect spark plug wire (if disconnected)
(Fig. 11).
1042
1
Figure 1 1
1. Spark plug wire
Lawn Preparation And Mowing
1. Review SAFETY INSTRUCTIONS and read
this manual carefully before operating mower.
2. Clear area of sticks, stones, wire, branches and
other debris which could be picked up or hit by
cutting blade and become thrown objects.
3. Keep everyone, especially children and pets,
away from area of operation.
4. Avoid striking trees, walls, curbs or other solid
objects. Never deliberately mow over any object.
5. If an object is struck, or mower starts to vibrate,
immediately stop engine, disconnect spark plug
wire and examine mower for damage.
6. Replace blade when necessary with an original
equipment replacement blade for best results.

GB–12
Operation
Starting Engine
Note: Follow steps in BEFORE STARTING
section.
1. Move throttle lever to (FAST) position
(Fig. 12).
1019
1
Figure 12
1. Throttle lever
2. Push primer three (3) times (Fig. 13). Wait about
two (2) seconds between each push.
Note: Do not use primer to restart a warm
engine after a short shutdown.
980
1
Figure 13
1. Primer
3. Hold blade control bail against upper handle
(Fig. 14).
1301
1
3
2
Figure 14
1. Blade control bail
2. Upper handle
3. Starter handle
4. Pull starter handle lightly until resistance is felt,
then pull sharply (Fig. 14). Let rope return to
handle slowly .
Stopping Engine
1. Move throttle lever to (SLOW) position
(Fig. 12).
2. Release blade control bail (Fig. 15). Both the
engine and blade will stop. See your dealer
immediately if they do not.
1302

Figure 15
1. Blade control bail

Operation
GB–13
To Restart Engine
1. Repeat STARTING ENGINE procedure with
throttle lever in (FAST) position.
2. If engine fails to start after three (3) pulls, repeat
steps 2–4 in STARTING ENGINE procedure.
Note: Do not use primer to restart a warm
engine after a short shutdown.
Adjusting Cutting Height
Each wheel is adjusted individually with a wheel
height adjustment lever. Cutting heights are 1”, 1!/2”,
2”, 2!/2”, 3” and 3!/2inches (25, 38, 51, 64, 74 and
86 mm).
POTENTIAL HAZARD
•Adjusting height-of-cut levers could bring
hands into contact with moving blade.
WHAT CAN HAPPEN
•Contact with rotating blade can cause
serious injury .
HOW TO AV
OID THE HAZARD
•Stop engine and wait for all movement to
stop before adjusting cutting height.
•Do not put fingers under housing when
adjusting height-of-cut.
1. To change cutting height pull adjusting lever
toward wheel and move to the desired position
(Fig. 16).
1021
1
Figure 16
1. Wheel height adjustment
lever
2. Release height adjust lever and seat securely in
notch.
Note: Set all four (4) wheels at the same
height.

Operation
GB–14
Mulching T ips
General Tips
Follow these instructions whether cutting grass or
leaves for the best cutting results and lawn
appearance:
•Maintain a sharp blade throughout the cutting
season. Periodically file down nicks on blade.
•Only mow dry grass or leaves. Wet grass and
leaves tend to clump on yard and may cause
mower to plug or engine to stall. They may also
be slippery to walk on and could cause you to
slip and fall.
POTENTIAL HAZARD
•Wet grass or leaves can cause you to slip
and contact blade.
WHAT CAN HAPPEN
•Blade contact can seriously injure you.
HOW TO AV
OID THE HAZARD
•Mow only in dry conditions.
•Set engine speed to fastest position. Maximum
horsepower provides best cutting results.
•Clean clippings or leaves from underside of
mower deck after each mowing.
•Keep engine in good running condition. Cutting
and recutting requires more horsepower.
•Clean air filter more frequently. Cutting and
recutting stirs up more clippings and dust which
clogs the air filter and reduces engine
performance.
Cutting Grass
•Grass grows at different rates at different times
of the year. In the heat of summer, it is generally
best to cut grass at the 2, 2.5 or 3 inch (51 mm,
63.5 mm, 75 mm) height-of-cut settings. Only
about !/3of the grass blade should be cut off.
Cutting below the 2 inch (51 mm) setting is not
recommended unless grass is sparse or it is late
fall when grass growth begins to slow down.
•When cutting grass over six inches tall, you may
want to first mow using the highest height-of-cut
setting and a slower walking speed; then mow
again at a lower setting for best lawn appearance.
If grass is too long and leaves clumps on top of
lawn, mower may plug and cause engine to stall.
•Alternate mowing direction. This helps disperse
clippings over 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 height-of-cut setting on your mower.
•Cut grass more frequently.
•Overlap cutting swaths instead of cutting a full
swath with each pass.
Cutting Leaves
•When cutting is complete, always be sure that
50% of the lawn shows through the cut leaf
cover. This may require one or more passes over
the leaves.
•Walk at a slower mowing speed if leaves are not
being cut up finely enough to be hidden down in
the grass.
•If you cut up a lot of oak leaves, you might want
to add lime to your grass in the spring. Lime
reduces the acidity of oak leaves.

GB–15
Maintenance
Continued safe and dependable operation requires routine maintenance.
Recommended Maintenance Schedule
Service Item Service Operation
5
Hours 25 Hours 50 Hours 100 Hours
Fasteners
Check blade and engine mounting fasteners
frequently . Keep all nuts, bolts and screws tight to
ensure safe operation.
X
Air Filter
Remove and clean each mowing season or every
25 hours. More frequently if operating
conditions are dusty. X
Spark Plug Clean, inspect and gap. Replace if necessary . X
Housing Clean built-up grass clippings and dirt. X
Blade
Sharpen or replace; maintain more frequently if
edge is dulled quickly in rough or sandy conditions.
X
Blade Brake
Check stopping time every 50 hours or at start of
each mowing season. Blade must stop within
3 seconds of releasing bail; if not see your
Authorized Lawn-Boy Service Dealer for repair .
X
Exhaust Ports
Clean every 50 hours or at least once each mowing
season. X
Fuel System
Check for leakage and/or deterioration of fuel hose.
Replace if necessary .X
Cooling System
Clean grass clippings, debris or dirt that clog
engine air cooling fins and starter . Clean more
frequently under dirty or high chaf f conditions.
X

Maintenance
GB–16
POTENTIAL HAZARD
•If you leave the wire on the spark plug, someone could start the engine.
WHAT CAN HAPPEN
•Accidental starting of the engine could seriously injure you or other bystanders.
HOW TO AV
OID THE HAZARD
•Pull the wire off the spark plug before you do any maintenance. Also push the wire
aside so it does not accidentally contact the spark plug.
Air Filter
Once every season or every 25 hours clean air filter;
more frequently under dusty conditions.
Note: Do not operate engine without air filter
element; extreme engine wear or
damage will occur.
1. To remove air filter, snap cover latch open,
swing to side and unhook (Fig. 17).
1320
12
Figure 17
1. Cover 2. Filter
2. Remove cover and air filter.
3. Wash air filter in laundry detergent or kerosene
(Fig. 18).
4. Squeeze to remove excess liquid and blot dry
with a paper towel or rag.
5. Apply one tablespoon (15 ml) of SAE 30W oil
to the air filter (Fig. 19).
988
Figure 18
989
Figure 19
6. Squeeze until oil is distributed evenly
throughout filter. Blot lightly with paper towel to
remove excess oil.
7. Replace filter with cleanest side facing
carburetor.
Note: Be sure filter is fully seated in air box
and does not pucker, allowing direct
passage of air and dirt.

Maintenance
GB–17
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 spark plug once a season or every 25
hours, whichever occurs first. Use a Champion
RJ12C spark plug or equivalent.
1. Pull wire off spark plug (Fig. 21). Remove spark
plug and clean with a wire brush, removing
carbon build–up. DO NOT SAND BLAST.
Check condition of plug for cracks and damaged
or worn electrodes. Replace if necessary.
2. Set spark plug gap at .035 inch (.85 mm)
(Fig. 20).
986
.035 in.
(.85 mm)
Figure 20
3. Install spark plug by hand, then torque to
180 in.–lbs. (15 ft.–lbs.) (20 N⋅m) (Fig. 21).
10421
Figure 21
1. Spark plug wire
4. Reconnect spark plug wire when maintenance is
completed.
Clean Mower Housing
A clean mower housing provides the best cutting
performance. Check for grass build-up and clean after
each use.
1. Disconnect spark plug wire (Fig. 21).
2. Run engine dry or remove gas with hand pump.
POTENTIAL HAZARD
•Gasoline is extremely flammable, highly
explosive and under certain conditions can
cause personal injury or property damage.
WHAT CAN HAPPEN
•Tipping mower may cause fuel leakage
from carburetor or fuel tank.
HOW TO AV
OID THE HAZARD
•Avoid fuel spills by running engine dry or
remove gas with hand pump, never siphon.
3. Tip mower onto right side (Fig. 22).
1128
Figure 22
4. Scrape built-up grass clippings and dirt from
mower housing with a hardwood scraper.
5. Tip mower upright.
6. Reconnect spark plug wire when maintenance is
completed.
7. Fill fuel tank with clean, fresh gasoline/oil mix.

Maintenance
GB–18
Blade
A straight, sharp blade provides maximum cutting
performance. Regularly inspect and sharpen blade.
POTENTIAL HAZARD
•Blade is sharp.
WHAT CAN HAPPEN
•Contact with sharp blade can cause serious
personal injury.
HOW TO AV
OID THE HAZARD
•Wear gloves or wrap sharp edges of the
blade with a rag.
Blade Straightness
1. Disconnect spark plug wire (Fig. 21).
2. Measure the distance from the bottom edge of
the mower housing to the blade tip (Fig. 23).
Rotate the blade 180°and measure to other blade
tip.
Note: If measurements are not within 1/8
inch (3.2 mm), blade should be
replaced. If, after blade replacement,
the measurements are still not within
1/8 inch (3.2 mm), the crankshaft
should be checked for straightness by
your Authorized Lawn-Boy Service
Dealer.
1005
Figure 23
Blade Removal
1. Remove blade nut (Fig. 24).
1023
1
23
Figure 24
1. Blade nut
2. Blade 3.
Blade driver
2. Remove blade from blade driver (Fig. 24).
3. Examine blade cutting edges for nicks, cutting
angle and sharpness. Sharpen or replace if
necessary.
4. Examine blade driver for bent or sheared drive
lugs. Replace if necessary .