Toro AC-1 User manual

AC-1 ENGINE SERVICE MANUAL
Table of Contents – Page 1 of 2
ABOUT THIS MANUAL
GENERAL INFORMATION
ENGINE SPECIFICATIONS
FUEL AND LUBRICATION
IGNITION
TORQUE SPECIFICATIONS
TORQUE SPECIFICATIONS (CONT)
SAFETY WARNINGS AND NOTES
PRODUCT IDENTIFICATION NUMBERS
OIL AND FUEL RECOMMENDATIONS
STARTING/STOPPING INSTRUCTIONS
SERVICE/MAINTENANCE INSTRUCTIONS
STORAGE INSTRUCTIONS
TROUBLESHOOTING
ENGINE FAILS TO START
ENGINE STARVES ON ACCELERATION
ENGINE IS HARD TO START
ENGINE STALLS
ENGINE FIRES INTERMITTENTLY
ENGINE DOES NOT PRODUCE MAXIMUM POWER
CARBURETOR FLOODS
ENGINE STOPS AFTER RUNNING BRIEFLY
ENGINE WILL NOT IDLE
ENGINE BACKFIRES OR MISFIRES
ENGINE WILL NOT ACCELERATE
ENGINE LACKS POWER OR STOPS DURING OPERATION
ENGINE VIBRATES EXCESSIVELY
ENGINE USES EXCESSIVE AMOUNT OF OIL
STARTER ROPE IS DIFFICULT TO PULL OR ENGINE LOCKS
DISASSEMBLY
TYPICAL DISASSEMBLY SEQUENCE
REMOVE MAJOR COMPONENTS
DISASSEMBLE ENGINE
INSPECTION AND REPAIR
CARBURETOR DISASSEMBLY AND REASSEMBLY
STARTER DISASSEMBLY AND REASSEMBLY
BREATHER DISASSEMBLY AND REASSEMBLY
SPARK ARRESTER SCREEN
PISTON/CONNECTING ROD DISASSEMBLY & ASSEMBLY
PISTON/CONNECTING ROD DISASSEMBLY & ASSEMBLY
CYLINDER HEAD INSPECTION & REPAIR

AC-1 ENGINE SERVICE MANUAL
Table of Contents – Page 2 of 2
INSPECTION AND REPAIR - Continued
CRANKCASE INSPECTION & REPAIR
MAJOR COMPONENTS INSPECTION & REPAIR
REASSEMBLY
TYPICAL ASSEMBLY SEQUENCE
ENGINE REASSEMBLY
INSTALL AIR FILTER BASE, AIR FILTER AND AIR FILTER COVER
ASSEMBLE HANDLE
ASSEMBLE COVERS

!
ABOUT THIS MANUAL
This Service Manualwas written expressly for the Toro AC-1 Four Stroke Engine. The Toro Company has made
every effort to make the informationinthis manual complete and correct.We are hopefulyou' findthis manual a
valuable addition to your service shop.
If you have any questions or comments regarding the information inside,
please contact usat the following address:
The Toro Company
Consumer Service Training Department.
81 11 Lyndale Avenue South
Bloomington,MN
55420
The Toro Company reserves the right to change product specifications orthis manual without notice.
Copyright@
All Rights Reserved
1996 The Toro Company

.........................
General Information B
2
Troubleshooting .#
.........................
..
Disassembly ..............................
4
InspectionandRepair ...................... ., ..
5
...........................
Reassembly ., ..

Table Of Contents
Engine Specifications ...............................
FuelandLubrication ...............................
ignition ......................................
Torque Specifications ...............................
SafetyWarningsAndNotes ...........................
Product IdentificationNumbers ..........................
OilAndFuelRecommendations .........................
RecommendedOilType ..........................
Checking the Oil ..............................
ChangingtheOil .............................
Recommended Fuel Type .........................
Definitionof Blended Fuels
Use of Blended Fuels
...........................
Use of Fuel Additives ...........................
.
.........................
1-3
1-4
1-4
1-4
1-6
1-7
1-7
1-7
1-8
1-9
1-9
1-9
1-9
1-9
Starting/stoppingInstructions
........................... 1-10
To StarttheEngine
............................ 1-10
To StoptheEngine ............................ 1-11
Service/maintenanceInstructions ........................ 1-11
AirFilter .................................. 1-11
SparkPlug ................................ 1-12
CarburetorAdjustment
.......................... 1-12
HighSpeedMixtureAdjustments
..................... 1-15
RockerArmtoValveClearanceAdjustment
............... 1-15
SparkArresterScreen .......................... 1-16
Storageinstructions ............................... 1-17
To Reactivate Unit for Service ....................... 1-17
SpecialTools
................................... 1-18
Definitionof Optimum Setting for Idle Speed Mixture and
1 -2

j Item
Engine Type
Displacement
Stroke
Average Compression
Piston Rings Side Clearance
Top Piston Ring Width
Top Piston Ring End Gap
Middle Piston Ring Width
Middle Piston Ring End Gap
Oil Piston Ring Width
OilPiston Ring End Gap
Rocker ArmtoValve Clearance
B
~
~~ ~~
___
~__~
__~
~~-~___
~~~
-
_____~.
~
~ ~~
_-
~-
~____
__~_____--
~~~ -~ ~__
~- - ~~ - ~~ __
~~
_-
~~ -~ ~
Air-cooled, 4-Cycle
~~
1 -3

11 Approx Fuel Tank Capacity
18 oz (530 ml)
TORQUE SPECIFICATIONS
tem
Carburetor/Air Filter Base Plate Mounting Screws
Carburetor Mount Insulator Screws
Clutch Housing/Drum Assembly Screws
Clutch Rotor
Cylinder Head Hex Nuts
Cylinder Screws
Spark Plug
Rear Engine Cover Screw
Front Engine Cover Screws
~ ~~ ~
~~~~~ -
~
-
~~
~~
_. ~ . ~ _~~_~~~-_____-~_-- --~__
- ~~
~ -. . -. .. _.._..____
~ - ..___ __
~~
. . . - -
~
1-4

SAFETY WARNINGS AND NOTES
The purpose of safety symbolsisto attract your atten-
tionto possible dangers. The safety symbols and the
explanations with them, deserve your careful attention
and understanding. The safety warnings do not by
themselves eliminate any danger. The instructions or
warnings they give are not substitutes for proper acci-
dent prevention measures. Some general warnings
follow.
WARNING:SpringUnderTension!
The rope starter on these engines contains a flat wire
spring thatis undertension.Weareye and hand protec-
tion when replacing worn or broken spring,incase it
should uncoil asit ishandled. Allow spring tension to
becompletelyrelievedandmakesurepulleydisen-
.
gages from spring before removing the pulley retain-
ers, pulley, and starter spring from housing.
,
WARNING:ElectricalShock!
Never touch electrical wires or components while the
engine is running. They can be sources of electrical
shock.
1 -6
/-
WARNING:HotSurfaces!
The muffler, cylinder, crankcase, trimmer cutting head,
and other engine surfaces get extremely hot from op-
eration. These surfaces remain hot for a short period
of time after the engineisstopped. To prevent severe
burns, allow the engineto cool completely before serv-
icing.
I
WARNING:ExplosiveFuel!
Gasoline may be presentinthe fuel tank, carburetor,
fuel lines, or crankcase. Gasolineisextremely flamma-
ble and its vapors can explode
if ignited. Keep sparks,
flames, and other sources of ignition away from the en-
gine.
Do not smoke while servicing the engine. Never
use gasoline as a cleaning agent.
Store gasoline onlyinapproved containers,
in well-
ventilated, unoccupied buildings, away from sparks,
~
flames, or other sources of ignition. Do not fill the fuel
tank while the engineis hot or running, since spilled
fuelcouldignite
if itcomes incontactwithhotparts or .
sparksfromignition. Do notstarttheenginenear
spilled fuel.
Do not smoke while handling gasoline or
fillingthefueltank.
i
WARNING:CrackedOrBrokenFlywheelFins
Can Become Projectiles!
Be careful not to crack or break any flywheel cooling
fins. They could fly
off during operation. If cooling fin:
are cracked or broken, replace the flywheel.
I

PRODUCTIDENTIFICATION
NUMBERS
When ordering parts, orinany communication involv-
ing an engine or product, always give the:
ModelNumber,and
SerialNumber
These numbers are located on a decal (or decals) af-
fixedtothe unit (Figure 1-1). The identification de-
.
will be located on the metal boom. The actual
location will vary depending on the type of product.
Figure1-1.ProductIdentificationDecal
1.0762.005
OILAND FUEL
RECOMMENDATIONS
WARNING: ExplosiveFuel!
Gasoline
Is extremelyflammable and itsvapors
provedcontainers, inwell-ventilated, unoccupied
buildings,away from sparks orflames. Do not fill
the fueltank while the engineis hot orrunning,
since spilled fuel could ignite if
it comes in contact
with hot partsor sparks from Ignition.Do not start
the enginenear spilledfuel. Donotsmoke while
handlinggasoline. Never use gasolineas a clean-
ingagent.
,. canexplode if ignited. Storegasolineonly inap-
NOTE: READ THESEINSTRUCTIONS CAREFULLY
BEFOREAttempting TO START
OR OPERATE
THIS UNIT. Using old oil or fuelcancauseengine
damage. This type ofdamage will void theengine
warranty
RecommendedOilType
Toro 4-cycleoil is recommended for useinthis engine
(Figure 1-2).
If another brand 4-cycleoil is used, use a
high qualitySAE 30 weight oilof API (AmericanPe-
troleum Institute) service classSG,
SF, SH.
Using the proper type and weight ofoilinthe oil panis
extremely important. Check theoil before each use
and change theoil regularly. Failureto use the correct
oil, or using dirty oil, can cause premature engine
wear and failure.
TORO,
FOUR-CYCLE
ENGINE OIL
I--------
Figure1-2.Recommended OilType. 3.6051.002
1 -7

Checking the Oil
The importance of checking and maintaining the
proper oil levelinthe oil pan cannot be overempha-
sized. Check the oil
BEFORE EACH USE as follows:
1. Makesurethe engine is stopped, level and is cool
so the oil has had time to. drain into the oil pan
(Figure
1-3 for straight shaft units or Figure 1-4
for curved shaft units).
Figure
1-3. Level Engine - Straight Shaft Unit. 3.6051.020
Figure 1-4. Level Engine - Curved Shaft Unit. 3.6051.004
2. To keep dirt, grass clippings, etc. out of the engine,
clean the area around the oil
fill plug before remov-
ing it.
3. Remove theoil fill plug; wipe theoil off. Reinsert it
into the crankcase. Thread the oil
fill plug into the
oil pan.
4. Remove theoil fill plug and check the oil level
(Figure
1-5).
1 -8
Figure 1-5. RemovingOil FillPlug. 2.6051.005
The oil level should be up to the top of the dipstick
(Figure
1-5).
Full (3.40z/lOOml)
Add Oil
L
Figure 1-6. Oil Level 3.6051.006
5. If the oil levelis low, add theoil to the top of
the dipstick (see Figure 1-6). Always check the
level with the dipstick before adding more oil.
L
I

Changing the Oil
Fora new engine, change the oil after the first 10
hours of operation. Thereafter, change theoil after
every 25 hours or before storing the unit for an ex-
tended period of time.
Change theoil while the engineisstillwarm. The oil
will flow freely and carry away more impurities.
Change theoil as follows:
1. Remove the oil fill plug.
2. Pour the oil into a container by
tipping
in a vertical position (Figure 1-7
tipping the trimmer
7). Be sure to allow
ample time for complete drainage. Dispose of oil
properly.
Figure
1-7. Pouring Oil. 3.6051.007
3. Fill the oil pan, with 3.4 oz (100 ml) of new oilof the
proper type, to the top of the dipstick.
4. Reinstall the oil fill plug and tighten securely.
NOTE: Make sure the O-ringis inplace on theoil fill
plug when checking and changing the oil.
NOTE: To prevent extensive engine wear or damage,
always maintain the proper oil levelinthe crankcase.
Never operate the engine with the oil level below the
bottom of the dipstick
Recommended Fuel Type
Use clean, fresh, regular grade unleaded gasoline less
than
60 days old.
NOTE: Alcohol blended fuel absorbs moisture
(water). Aslittle as
1 % moistureinthe fuel can cause
fuel to separate and form acids when stored.
If these types of fuel must be used, use freshfuel (less
than
60 days old).
Definition of Blended Fuels
Today's fuels are often a blend of gasoline and oneOr
more oxygenates such as ethanol, methanol or MTBE
(ether).
Use of Blended Fuels
If you choose to use a blended fuel or its use is un-
avoidable, the following precautions are recom-
mended.
1. Alwaysusefreshfuel.
2. Use the special additive Toro Gas Conditioner/
Stabilizer, STA-BIL
(R) or an equivalent.
3. Drain the fuel tank and run the engine dry before
storing the unit.
Useof Fuel Additives
The use of fuel additives, such asToroGas Condi-
tioner/Stabilizer, STA-BIL Gas Stabilizer or an equiva-
lent, will inhibit corrosion and minimize the formation
of gum deposit. Add
0.8 oz (23 ml) per gallon of fuel
per instructions on the container. NEVER add fuel ad-
ditives directly to the unit's fuel tank. Using a fuel addi-
tive can keep fuel fresh for up to
60 days.
1-9

STARTING/STOPPING
INSTRUCTIONS
To Start the Engine
1. Set the unit on the ground, check the oil levelinthe
oil pan, and put the ignition switchinthe “RUN”
(I)
position (Figure 1-8).
Figure 1-8. Ignition Switch and Throttle Trigger.
3.6051.008
2. FULLY PRESS AND RELEASE the primer bulb 5 to
7 times (Figure 1-9).
NOTE: For a warm engine, go directlyto step 5
(place the choke lever directlyinthe “PARTIAL” choke
position).
3. Place the choke lever in the FULL “CHOKE” posi-
tion (Figure 1-9).
---Run position
choke
Partial Choke
Figure
1-9. PrimerBulb,ChokeLeverandChoke ,
Positions. 3.6051.009
4. With the unit on the ground, pull the starter rope
quickly until the engine sounds likeitwants to run
(no more than
5 pulls) (Fig. 1-10).
Figure 1-1
0. Pulling the Starter Rope. 3.6051.010
1-10

5. Place the choke leverinthe “PARTIAL” choke posi-
tion (see Figure1-9on page 1.4). Pull the starter
rope quickly until the engine starts (no more than
5 pulls).
6. If the engine does not start, repeat steps 2 to 8.
7. Run the engine for 30 seconds, with the throttle
lever fully squeezed (see Figure 1
-6), towarm up.
Place the choke leverinthe “RUN” position
(Figure 1-9).
NOTE: Incolder weather, run the engine for 2 to 3
minutes to warm up.
To Stop the Engine
Place the ignition switchinthe “STOP position (see
Figure 1-8).
SERVICE / MAINTENANCE
INSTRUCTIONS
Air Filter
NOTE:
CLEAN AND RE-OIL THE AIR FILTER
EVERY 10HOURS
OF OPERATION. The air filteris
one of the most important areas to maintain.
If it isnot
maintained as follows, poor engine performance and
severe engine damage can result.
1. Remove the three
(3) screws on the carburetor/air
filter cover assembly. Remove the air filter cover
and air filter. Referto
Part 3 - Engine Disassembly
\
2. Wash the air filterindetergent and water
(Figure 1-11). Rinse the air filter thoroughlyin
clean water and allow
it to dry.
L
Figure 1-1 1. Washing Air Filter Element. 3.6051.011’
3. Apply clean SAE 30 oiltothe air filter (Figure 1-12).
I
I
Figure1-1 2. OilingAirFilter Element. 3.6051.012
4. Squeeze the air filterto ensure that theoil isspread
throughout the entire filter (Figure 1-13).
1-11

L
Figure 1-13. Squeezing ExcessOilfrom Air Filter
Element.
3.6051.013
5. Reinstall the air filterinthe carburetor/airfilter
base. Referto
Part 5 - Engine Reassembly
Spark Plug
Use a Champion RDZ19H spark plug. Every 50 hours
of operation, remove the spark plug, checkitscondi-
tion, and reset the gap or replace with a new plug as
necessary. Allow the engine to cool before removing
the spark plug.
WARNING: ElectricalShock!
Never touch electrical wires or components while the
engineisrunning. They can be sources of electrical
shock.
1. Before removing the spark plug, clean the area
around the base of the spark plugto keep dirt and
debris out of the engine.
2. Disconnect the spark plug wire and remove the
spark plug from engine.
3. Inspect the spark plug for carbon buildup and clean
if necessary. Replace the plug if it isbadly burnt or
if reuseisquestionable.
1-12
NOTE: Donotcleanthesparkplug inamachine ~
which uses abrasive grit. Some grit could remain on
the spark plug and enter the engine causing extensive
damage.
4. Check the spark plug gap using a wire feeler gauge.
Set the gap to
0.025 in (0.635 mm)(Figure 1-14).
5. Reinstall the spark plug and torqueto 100-110 in-lb
(1 1.3-1 2.3
N-m).
Figure 1-14. Spark Plug Gap. 3.6051.014
CarburetorAdjustment -
These engines are equipped with a diaphragm-type
carburetor.Thecarburetorhasbeencarefully cali-
~
brated at the factory.Inmost cases, no further adjust-
ment will be required.
The condition of the air filterisvery important to the
(
eration of the trimmer. A dirty air filter will restrict the
air flowto the carburetor. Thisinturn upsets the fuel-
air mixtureinthe carburetor. The resulting symptoms
are often mistaken for an out-of-adjustmentcarburetor
Therefore, check the condition of the air filter before
adjusting the carburetor. Referto “Air Filter“ Serv-
ice/Maintenance Instructions.
I-
-

If the following conditions are experienced,it may be
necessary to adjust the carburetor.
The engine will not idle
The engine hesitates or stalls on acceleration.
The loss of engine power, which is not corrected
by cleaning the air filter, muffler, spark arrester
screen or adjusting the rocker arm to valve
clearance
The engine operatesinan erratic or fuel-rich
condition
NOTE: Follow these carburetor adjustment proce-
dures carefully. An incorrectly adjusted carburetor can
cause severe engine damage.
Make sure the unitisfully assembled before
making carburetor adjustments.
Fortrimmers
and brushcutters, make sure
the boom, cutting head, and line guard are installed
and the cutting line is extended to its full cutting length.
The carburetor has three basic adjustments: the idle
speed adjustment, the idle speed mixture adjustment,
and the high speed mixtureadjustment(Figure 1-15).
Mixture Needle
Figure
1-1 5. Carburetor Adjustments. 3.6051.015
407000001-Use the following carburetor adjustment
instructions:
1.
Initial Idle Speed Setting: Turn the idle speed
screw untilitstops.
2. Initial High Speed Mixture and Idle Speed Mix-
ture Settings:
Turn both the high speed mixture
and idle mixture needles
in(clockwise) until they
are lightly seated.
3. Turntheneedles out the
following number
of turns:
HighSpeedMixtureNeedle:1turn
IdleSpeedMixtureNeedle: 1 turn
NOTE: Turn the high speed mixture and idle mixture
needles finger-tight. Do not force the needles with a
screwdriver as this can damage the tips of the needles
and the seatsinthe carburetor body.
4. Start the engine and let it run for
3 to 5 minutes
with the throttle lever fully squeezed.
5. Release the throttle trigger and let the engine idle.
Turn the idle speed screw
out (counterclock-
wise)
until the speed decreases and the bump
head stops rotating.
6.
Final Idle SpeedandMixtureAdjustments:
Adjust the idle speed screw and idle speed mix-
ture needle for the smoothest engine idle using
the following procedure.
Do not squeeze throttle
trigger when adjusting the idle speed screw and
idle speed mixture needle.
a.Setthe idle speed mixture needle
at the optimum setting
(Figure 1-16). See “Definition of Optimum
Setting” on page
1-1 5.
1-13

b
b. Squeeze the throttle trigger. If the engine
falters or hesitates as
it accelerates, turn the
idle speed mixture needle
out (counterclock-
wise) 1/16 turn at a time
until the engine ac-
celerates rapidly.
c.
If the idle speed has changed significantly be-
cause of steps a. and b. above, readjust the
idle speed screw.
7. FinalHighSpeedMixtureSetting:
Adjust the high speed mixture needle as follows:
a. Squeeze the throttle trigger and
run the unit at high speed for
3 to 5 minutes.
b. While squeezing the throttle trigger fully, set
the high speed mixture needle at the optimum
setting. See “Definition of Optimum Setting”
on page1-15.
NOTE: The high speed mixture needle adjustment
must be the last adjustmentmade
on the carburetor. If
the idle speed mixture needleisadjusted, the high
speed mixture needle must be readjusted.
8. Make sure the air filter cover is reinstalled securely
before placing the unit back into service.
For Units with Engine Serial Number 407000001
and Greater-Use
the following carburetor adjust-
ment instructions:
1.
Initial Idle Speed Setting: Back the idle speed
screw (Figure 1-15)
out (counterclockwise) until
it
does not contact the carburetor throttle lever.
Then turn the screw
in (clockwise) untilit just be-
gins
to move the throttle lever; then continue turn-
ing
2 full turns.
2. Initial High Speed Mixture and idle Speed
Mixture Settings:
Turn both the high speed mix-
ture and idle speed mixture needles
in (clock-
wise)
until they are lightly seated.
1-14
3. Turn the needles out (counterclockwise) the
following number of turns:
High Speed Mixture Needle: 1 1/8 turns
Idle Speed Mixture Needle1 1/8 turns
NOTE: Seat the high speed mixture and idle speed
mixture needles using finger pressure. Forcing the mix-
ture needles will damage the tips of the needles and
the seatsinthe carburetor body.
4. Start the engine and letit run for 3 to 5 minutes
with the throttle lever fully squeezed.
5. Release the throttle trigger and let the engine idle.
If the engine stops, turn the idle speed screw in ~
(clockwise) 1/8 turn at a time (as required) until
the engine idles.
6. FinalHighSpeedMixtureNeedleAdjustment:
a. While squeezing the throttle trigger fully, set
the high speed mixture needle at the optimum
setting. See “Definition of Optimum Setting”.
NOTE: After the final high speed mixture needle ad-
justment is made, no more high speed mixture needle
adjustmentstothe carburetor are necessary.
7. Final Idle Speed and Idle Speed Mixture
Adjustments:
Adjusttheidle speed screw and ’
idlespeed mixture needle for the smoothest en-
gineidleusingthefollowingprocedure.Donot
~
squeeze the throttle trigger when adjusting the idle
speed screw and idle speed mixture needle.
a.Settheidlespeedmixtureneedleatthe
~
optimum setting (Figure 1-16). See “Definition’
of Optimum Setting”.
b. Turn the idle speed mixture needle
out
(counterclockwise) 1/8 turn
tothe rich side ~
of optimum.The engine should idle and accel-
erate smoothly.

8. FinalIdleSpeed Adjustment: Adjusttheidle
speed by turning the idle speed screw
in(clock-
wise)
or out (counterclockwise) until the cutting
head does not rotate.
Do not squeeze the throttle
trigger when adjusting the idle speed screw.
9. Make sure the air filter coveris reinstalled securely
before placing the unit back into service.
Definitionof Optimum Setting forIdle Speed
Mixture and High Speed Mixture Adjustments
Always set the idle speed mixture needle and high
speed mixture needle at the optimum setting.To find
the optimum setting, use the following procedure.
1.Turnthe adjusting needle
out (counterclockwise)
from the preliminary setting until the engine speed
decreases (rich). Note the position of the needle.
2. Turn the adjusting needle in(clockwise). The en-
gine speed may increase as the needleisturned
in(lean). Note the position of the needle.
3. Set the adjusting needle midway between the rich
and the lean settings (Figure 1-16).
Midpoint
Adjust to Lean
I
Figure 1-16. Optimum Setting. 3.6051.016
Rocker Armto Valve Clearance Adjustment
Every
50 hours of operation, remove therocker arm
cover and check the rocker armtovalve clearance.
1. Remove the four (4) screws from the engine cover.
Remove the engine cover. Remove the rocker arm
cover. Referto
Part 3 - Engine Disassembly.
2. Position the crankshaft so that the pistonisat the
top of the compression stroke (both rocker arms
are free and loose).
3. Measure the clearance between the valve stems
and rocker arms, using a
flat feeler gauge (Figure
1-17).
Figure 1-17. Measuring the Rocker Armto Valve
Clearance.
3.6051.017
The recommended rocker armtovalve clearance for
both the intake and exhaustis
.003-.006 in
(.076 mm-,152 mm).

b
4. If the clearance is not within specification, adjust as
follows:
a.Turn the adjusting nut (Figure 1-18), using a
5/16 in (8 mm) wrench or nut driver.
To increase the rocker arm to valve clearance, turn
the adjusting nut counterclockwise.
To decrease the rocker arm to valve clearance, turn
the adjusting nut
clockwise.
b. Recheck the clearance with a flatfeeler gauge
and readjust as necessary (see Figure 1-1
7).
5. Reinstall the rocker arm cover, using a new gasket.
Torque the rocker arm cover screw to
20-30 in-lb
(2.2-3.4 N.m).
Figure 1-18. Adjusting Nuts. 2.6051.018
6. Install the breather hose to the air filter base.
7. Reinstall the engine cover and screws. Refer to
Part
5 - Engine Reassembly.
Torque the top screws to
15-20 in-lb(1.7-2.2 Nom).
Torque the front screw to 20-25 in-lb(2.2-2.8 Nom).
Torque the rear screw with washer to 30-35 in-lb(3.5-
4.0 Nom).
Spark Arrester Screen
This unitisequipped with a spark arrester screen.
Every
50 hours of operation, check the spark arrester
screen for debris and/or deposits.
WARNING:HotSurfaces!
Make sure the muffleris cool before checking the
spark arrester screen to prevent injury.
1. Remove the spark arrester cover screw and cover
(Figure 1-1
9).
Figure 1-1 9. Spark Arrester Screen. 3.6051.019
2. Push the spark arrester screen out of the cover.
3. Inspectthesparkarresterscreen.
If the screen is clean, reinstall the screen,
cover and screw.
If the screen is plugged,
replace it.
4. Torque the screw to 15-20 in-lb(1.7-2.2 N-m).
1-16