Toro 20441, 20442, 20708, 20709, 20710 Service Manual

V-ENGINE SERVICE MANUAL

Table of Contents – Page 1 of 3

ABOUT THIS MANUAL

SAFETY INFORMATION

SPECIFICATIONS ENGINE SPECIFICAT IONS ENGINE FASTENER TORQUE REQUIREMENTS CARBURETOR SPECIFICATIONS

SPECIAL TOOL REQUIREMENTS SPECIAL TOOL REQUIREMENTS - REQUIRED SERVICE SUPPLIES TORO 2-CYCLE V ENGINE TOOL REQUIREMENTS

TROUBLESHOOTING ENGINE WILL NOT START WHEN "COLD" ENGINE WILL START WHEN "COLD", BUT NOT WHEN "HOT" ENGINE WILL NOT PRODUCE SPARK ENGINE FLOODED WITH FUEL ENGINE HAS LOW COMPRESSION ENGINE LACKS POWER ENGINE SURGES ENGINE BACKFIRES ENGINE OVERHEATS ENGINE VIBRATES EXCESSIVELY ENGINE CRANKSHAFT WILL NOT TURN ENGINE PRODUCES MECHANICAL KNOCKING SOUND ENGINE PRE-IGNIT ES ENGINE SMOKES EXCE SSI VE L Y ENGINE STALLS SPARK PLUG FOULED

MAINTENANCE RECOMMENDED MAINTENANCE SCHEDUL E AIR FILTER - CLEANING SPARK PLUG SPARK PLUG GAP SPARK PLUG TORQUE EXHAUST SYSTEM - CLEANING REASSEMBLING

PRIMER START CARBURET O R TROUBLESHOOTING - ENGINE STARTS HARD ENGINE RUNS RICH ENGINE RUNS LEAN FUEL LEAKS FROM CARBURETOR INTRODUCTION - IDENTIFICATION

V-ENGINE SERVICE MANUAL

Table of Contents – Page 2 of 3

PRIMER START CARBURETOR - Continued OPERATION GOVERNOR GOVERNOR ADJUSTMENT SERVICING - PRELIMINARY CHECK DISASSEMBLY CLEANING AND INSPECTION ASSEMBLY INSTALLATION PRESETTING THE GOVERNOR SERVICING THE AIR FILTER

FUEL SYSTEM OPERATION - FUEL TANK FUEL CAP SERVICE - FUEL CAP TANK REMOVAL CLEANING TANK INSTALLATION FUEL STORAGE

IGNITION SYSTEM TROUBLESHOOTING - PROCESS SPARK PLUG - OPERATION SERVICE CD PACK - ADVANTAGES OPERATION AIR GAP ADJUSTMENT REMOVAL/INSTALLATION FLYWHEEL - OPERATION REMOVAL INSTALLATION

REWIND STARTER OPERATION RECOIL ASSEMBLY REPLAC EM ENT STARTER ROPE REPLACEMENT

ENGINE ADVANTAGES/DESCRIPTION OPERATION SERVICE TIPS - CYLINDER/CRANKCASE HALVES OIL SEALS CORE PLUGS MUFFLER BAFFLE

V-ENGINE SERVICE MANUAL

Table of Contents – Page 3 of 3

ENGINE - Continued MUFFLER PLATE SCREWS EXHAUST PORTS CARBURETOR GASKETS REMOVAL DISASSEMBLY INSPECTION AND REPAIR REED VALVE SERVICE REASSEMBLY REINSTALLING EXTERNAL COMPONENTS

PIVOTING ZONE START BRAKE SYSTEM PIVOTING ZONE START BRAKE - INTRODUCTION OPERATION DISASSEMBLY ASSEMBLY

APPENDIX POWER HEAD - EXPLODED VIEW IGNITION AND EXHAUST - EXPLOD ED VIEW STARTER AND PRIMER START CARBURETOR - EXPLODED VIEW PRIMER START CARBURETOR ASSEMBLY - EXPLODED VIEW

ABOUT

THIS

MANUAL

This manual was written expressly for the Tor0 made every effort to make the information in this manual complete and correct.

This manual was written with the service' technician in mind. The book is divided into two sections, Quick Reference information (specifications, troubleshooting, etc.) and servicing information (servicing procedures).

We hope you find this manual a valuable addition to your service shop. any questions or comments regarding this manual, please contact us at the following address:

V

Engine. The Tor0 Company has

If

you have

The Toro Company Consumer Service Department

81

11

Lyndale Avenue South

MN

Bloomington,

The Tor0 Company reserves the right to change product specifications or this

manual without notice.

55420-1

196

Copyright(R)

All

1995

The Tor0 Company

Rights

Reserved

Safety Information

This safety symbol means WARNING or PERSONAL SAFETY

-

INSTRUCTION

safety. Failure to comply with the instruction may result in personal

injury or even death.

This manual is intended as a service and repair manual only. The safety instructions provided herein are for troubleshooting, service and repair of the engine only. The Operator’s Manual will contain safety information on the complete product powered by the Tor0

2-

instructions are available through:

The Tor0 Company Publications Department

81

1

Lyndale Avenue South

Bloomington, MN

read the instruction because it has to do with your

Cycle V engine. Operator’s Manuals with complete

55420-1

196

U.S.A.

Avoid unexpected starting of the engine

Always turn disconnect the spark plug before attempting cleaning, adjustment or repair.

Avoid lacerations and amputations

Stay clear of all moving parts when the engine is running. Treat all normally moving parts as if they were moving whenever the engine is running or has the potential to start.

Avoid burns

Do

or shortly after it has been running.

Avoid falls

Do

slippery surfaces or questionable.

Avoid fires

Wipe up any spilled fuel or oil immediately.

Avoid asphyxiation

Never operate an engine in a confined area without proper ventilation.

....

off

the powered product and

...

not touch the engine while it is running

...

not operate the powered product on

if

footing is

...

Avoid spilling fuel and never smoke while working with any type of fuel.

Avoid accidental misuse of fuel.

Always store fuel in a properly labeled container designed for gasoline.

Avoid injury due to inferior parts

Use only TOR0 original parts to ensure that important safety criteria are met.

Avoid injury

Always clear the area of bystanders before starting or testing powered equipment.

Avoid injury due to projectiles

Always clear the area of sticks, rocks, or any other debris that could be picked up and thrown by the powered equipment. Keep all safety shields in place

Avoid modifications

Never alter or modify any part unless it is a factory approved procedure.

Avoid unsafe operation

Always test the safety systems after making adjustments or repairs on the machine.

to

bystanders

...

..

...

Avoid fires and explosions Use a container designed for gasoline.

...

QUICK REFERENCE SECTION

Specifications

Special Tool Requirements.

Troubleshooting

Maintenance

..............................................

............................................

...............................................

SERVICE SECTION

Primer Start Carburetor.

Fuel system

...............................................

...................................

......................................

Ignition System

Rewind Starter.

Engine

Pivoting Zone Start Brake.

Appendix

....................................................

..................................................

.............................................

~~

....................................

I

~~

Reference Section

1-1

Engine Specifications. 19

Engine Fastener Torque Requirements 1-4

Carburetor Specifications 1-4

1-2

Reference Section

Engine Specifications

I

Reference Section

1

-3

Bolt, Blade Nut, Flywheel Screw, Air vane

Screw, Carburetor mounting

81.6 N-m)

Screw, CD ignition pack Screw, Cylinder to crankcase Screws, Engine mounting Screw, Ground strap stop Screw, Muffler cover Screw, Muffler plate Screw, Reed*

Screw, Shroud

*Use thread-locking compound

See page

2.2

~-

Carburetor Specifications

90

110

in

lbs (10-12 N-m)

105

I

115

in

lbs

(.I2

350-400 in Ibs

15

25

in Ibs (1.7 2.8

150

190

140 200 in

10

13 in Ibs(1.1-1.5

65 75 in

20

25 in Ibs (2.3 2.8 N-m)

(39

in Ibs (I7 22 Nom)-.

Ibs

(16

Ibs

(7,3 -8.4 N-m)

I3

N-m

45 N-m)

N-m)

22 N-m)

N-m)

1-4

Reference Section

QUICK REFERENCE SECTION

Specifications

Special

Troubleshooting

Maintenance

Tool

Requirements.

SERVICE SECTION

Primer Start Carburetor.

Fuel system

Ignition System

2

Rewind Starter.

Engine

Pivoting Zone Start Brake.

Appendix

Reference

Section

2-1

REQUIRED SERVICE SUPPLIES

2-2

Reference

Section

QUICK REFERENCE SECTION

Specifications

Special

Troubleshooting

Maintenance

Tool

Requirements.

SERVICE SECTION

Primer Start Carburetor.

Fuel system

Ignition System

3

Rewind Starter.

Engine

Pivoting Zone Start Brake.

Appendix

Reference Section

3-1

ENGINE WILL NOT START WHEN “COLD”

3-3

ENGINE WILL START WHEN “COLD”, BUT NOT WHEN “HOT”

ENGINE WILL NOT PRODUCE SPARK.

ENGINE BACKFIRES

ENGINE OVERHEATS.

ENGINE VIBRATES EXCESSIVELY.

ENGINE CRANKSHAFT WILL NOT TURN..

SPARK PLUG FOULED.

3-3

3-5

3-7

3-2

Reference Section

ENGINE WILL NOT START WHEN “COLD”

Remedies

Fill with Drain and flush tank and float bowl,

clean fresh unleaded, properly mixed fuel Clean and backflush fuel tank. Replace fuel tank

necessary

Wash and re-oil air cleaner element

clean, fresh,

properly mixed, unleaded fuel

fill

tank with

if

Replace

See “ENGINE WILL NOT PRODUCE Check for loose blade Check See “ENGINEHAS LOW COMPRESSION table See “ENGINE

the spark

plug

FLOODED”

WITH FUEL” table

SPARK

table

ENGINE WILL START WHEN “COLD”, BUT NOT WHEN “HOT”

I

See ‘ENGINE-FLOODED WITH FUEL” table

10%

fuel Use no more than

See: ENGINE OVERHEATS table Clean bowl vent

ethanol blend

Reference Section

3-3

ENGINE FLOODED WITH FUEL

Remedies

Let unit sit, retry, or, remove spark plug, pull rope

several times.. Reinstall plug. Try again. Adjust Wash and re-oil cleaner element

throttle

cable

Replace spark

Clean carburetor, replace failed parts

Clean

ENGINE HAS LOW COMPRESSION

plug

Dirty plugged main fuel and/or air bleed circuits

3-4

Remedies

Clean main fuel circuit and all air bleed circuits Check sealing surfaces, oil

plugs

Check filters and fuel line

Reference Section

3-5

ENGINE PRODUCES MECHANICAL KNOCKING SOUND

Remedies

Inspect and tighten blade bolt to correct torque Inspect and tighten flwheel nut to correct torque

See

Inspect and repair and tighten-nuts to correct torque

Tighten bolts

ENGINE SMOKES EXCESSIVELY

“ENG!NE

PRE-IGNITES’ table

ENGINE STALLS

3-6

Remedies

Refill with fresh fuel-of the correct mixture Unload engine and-restart See “SPARK PLUG FOULED- table Replace fuel cap Inspect and repair to remove unwanted ground Clear vent of obstruction Clear debris from fins or cause of overheating Refill-with fresh, and

Reference Section

properly

mixed, fuel

SPARK

PLUG

FOULED

possible

Incorrect spark plug Carburetor running too rich

Clogged air cleaner element Weakignition Worn rings and/or cylinder Use of leaded fuel

Fuel/oil mixture too rich

Wrong oil

Causes

~-

syslem

Use correct spark plug Clean-!rebuild carburetor

or

Clean and re-oil element

Replace CD ignition pack Rebuild engine or

Drain fuel tank and replace with fresh, unleaded regular fuel, having the correct oil mixture Drain fuel tank and

(32:

1

)

Use Tor0 2-Cycle, or

short block

fill

NMMA

replace

with fuel of correct mixture

certified ashless oil

Reference Section

3-7

QUICK REFERENCE SECTION

Specifications

Special Tool Requirements.

Troubleshooting

Maintenance

SERVICE SECTION

Primer Start Carburetor.

Fuel system

Ignition System

Rewind Starter.

Engine

e

Pivoting Zone Start Brake.

Appendix

Reference Section

4-1

AIR

FILTER

Cleaning

4-3

Spark

Exhaust system

Plug

Spark Plug Gap Spark Plug Torque

Cleaning

Reassembling 4-7

4-4 4-5

4-5

4-2

Reference Section

RECOMMENDED MAINTENANCE SCHEDULE

25

50

100

Hours

item

Fasteners Air filter Spark plug

Housing Self-propelled

Mechanism Blade

Blade brake

Lubrication Exhaust

Fuel system Cooling system

ports

Comments

Check blade and engine mounting fasteners frequently. Keep all nuts, bolts tight

25

Remove, and clean each mowing season or every

more frequently

if

operating conditions-

are

dusty.

necessary

Remove buildup- of grass clippings and-dlrt Clean grass clippings and debris under drive belt and drive

belt cover Sharpen or replace; maintain more frequently

~-

dulled quickly in rough. or sandy conditions

50

Check stopping time every

hours or at the start of each

mowing season. The blade must stop within releasing the bail;

if

not, repair

or-replace

if

3

seconds of

Grease rear height adjuster brackets (self-propelled models only)

Clean every

50

hours or at least once each mowing season

Check for leakage and/or deterioration of fuel hose; replace necessary Clean grass clippings, debris or dirt that clog the engine air

cooling fins;

do more often under dirty or high chaff

conditions.

hours:

edge is

if

FILTER

COVER

Reference Section

751.2.51

AIR

FILTER

Cleaning

Once every season, or every filter housing and element.

under dusty conditions. NOTES:

filter in place. Doing cause excessive engine wear.

To

swing the cover to the side and unhook. Remove the cover and air filter.

Do

not operate the engine without the air

so

remove the air filter, snap the cover latch open,

25

hours, clean the air

Do

so

more frequently

may damage the engine

or

4-3

AIR

FILTER

Cleaning (cont'd)

2.

Wash the air filter in dish or laundry

detergent. Squeeze the filter to remove excess liquid and blot dry with a clean paper towel or rag.

out the element

3.

Apply one tablespoon of SAE 1OW30, or

similar, oil to the air filter. Lightly squeeze the filter until the oil is distributed evenly throughout the filter. Blot lightly with a

clean paper towel or rag to remove excess

oil.

Reinstall the filter with the cleanest side facing the carburetor.

NOTE:

in the air box and is not puckered (allowing

direct passage of air and dirt to carburetor).

(cont'd

NOTE:

or

damage

Be sure the filter is properly seated

Do

not wring

may

occur.

751.2.5130.801

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

25

or every

PLUG TYPE: Champion RJ12C

Remove the spark plug and clean brush, removing carbon build up.

SANDBLAST.

damaged or worn electrodes. Replace if necessary.

hours, whichever occurs first.

it

with a wire

DO

NOT

Check the plug for cracks,

Reference Section

751.2.5130.803

Spark Plug Gap

Set the spark plug gap to

Install the spark plug finger tight, then torque to 180

in Ibs (15

gasket are seated.

ft.

Ibs.) (20 Nm), or 1/4 turn after plug and

.035"

(.85mm).

Spark Plug Torque

0490

751.1

A4

WARNING: Disconnect the spark plug wire to prevent accidentally starting the engine.

TOOLS

1.

REQUIRED:

1/2" drive

5/8"

socket

3/8"

(9mm) wooden dowel

Wearing heavy duty gloves hold the blade while removing the bolt. Using the 1/2" drive and

5/8"

secures the accelerator, blade and blade retainer. Remove the accelerator, blade and blade retainer.

Reference Section

Exhaust

socket, remove the blade bolt that

System

Cleaning

4-5

Exhaust

System

(cont'd)

Cleaning

2.

3.

(cont'd)

The small louvers in the muffler cover must be open and free of debris. Clean if necessary.

To remove the muffler cover, remove the three bolts. Drop the cover down to inspect the condition of the exhaust ports, etc.

4.

4-6

Pull the starter rope until the piston covers the exhaust ports, this prevents carbon from falling into the cylinder. Clean exhaust

3/8"

port area with the dowel.

NOTE: Do not scratch the piston or allow carbon to fall into the cylinder.

(9mm) wooden

Reference Section

751.1.0490.79

Reassembling

Insert the three bolts into the muffler cover 1.

and torque to 150-1

90

in Ibs (17-22 Nm).

751.1.O490.72

2. Check the condition

If

OK,

re-install the blade retainer.

3.

Re-install the blade and accelerator with the 7/16 20 blade bolt. Torque the bolt to 50 Ibs (68 Nm)

of

the key and keyway.

ft

Reference Section

4-7

QUICK REFERENCE SECTION

Specifications

Special

Troubleshooting

Maintenance

Tool

Requirements.

SERVICE SECTION

Primer Start Carburetor.

Fuel system

Ignition System

Rewind Starter.

Engine

Pivoting Zone Start Brake.

Appendix

Service

Section

5-1

TROUBLESHOOTING 5-3

Engine Starts Hard Engine Runs Rich Engine Runs Lean Fuel Leaks From Carburetor

INTRODUCTION 5-4

Identification 5-4

Operation Governor

Servicing 5-5

Removal Disassembly Cleaning and Inspection

Assembly

Installation 5-11 Presetting the Governor 5-12

Final

check

5-3

5-4

5-5

5-7

5-9

5-12

Service Section

I

Fuel Leaks From Carburetor

Service Section

5-3

INTRODUCTION

Identification

The primer start carburetor is easily identified by the primer bulb mounted to the aluminum heat shield/ primer bracket and the black Minion carburetor body.

This is a single circuit, fixed jet, non-adjustable carburetor manufactured by The Toro Company.

5

Operation-

As

the crankshaft rotates, the piston moves up and down in the cylinder. alternately creating pressure or a partial vacuum in the crankcase.

When

a

vacuum is created by upward pressure movement, the reed valve opens and air rushes through the carburetor throat.

(

The carburetor is a venturi tube end, with

rushes through this tube air pressure at the center of the passage is lowered. By inserting a tube from the carburetor float bowl into the venturi, lower air pressure at the venturi draws fuel up through the tube. The fuel/oil mix is then

picked up by, and mixed with, the incoming air. The fuel/oil/air mixture enters the crankcase through the reed valves, thereby sustaining operation of the engine as long as fuel is supplied to

a

smaller center passage). When air

it.

large at each

REED

VALVE

VENTURI,

I

CENTER

FIRST

STROKE

751.2.5130.85

I

5-4

Service Section

Venturi

Effect

751.2.5130.8O6

Governor

The sail of the air vane governor is attached to the throttle valve the rotating flywheel attempts to close the throttle. The governor spring resists this force and attempts to open the throttle. The balance between these forces is the governed engine speed.

of

the carburetor. Air flow created by

two

I

751.2.5130.807

Governor Adjustment

To

change the RPMs of the engine you change the tension of the governor spring. Spring tension is changed via an adjustable collar. When the collar is turned each “click” produces approximately a RPM change in engine speed.

50

SERVICING

Service

The primer start carburetor used in V Engine has an all Minlon housing with a fixed high speed jet and an adjustable float.

Perform the following preliminary checks to

eliminate some contribute to hard starting:

Ignition system-

adjusted to specs and are the correct components.

Fuel tank fiiter-

of

the other possibilities that may

ensure that all components are

must not be plugged.

Section

5-5

SERVICING

(cont’d)

Preliminary Check (cont’d

Fuel cap vent- hole must not be plugged.

Air filter-

Crankcase seal-

installed properly and in good condition; torque

value on the sump cover bolts must be correct.

must be cleaned and oiled.

Crankcase seals must be

Carburetor flange gaskets and heat

shield-

Exhaust Fuel-

If

must be installed correctly

ports-

mixture must be fresh, not unknown, etc.

unknown, flush out.

must not be restricted.

751

.I

,0490.45

Governor air vane-

Removal

Tools

Required:

Flat Blade Screwdriver Needle

1.

Disconnect the spark plug wire.

2.

Remove the fuel line and drain; remove the

fuel tank (see page

3.

Open and remove the air cleaner cover and air filter element. Remove the Spit Cup, present, by gently prying the ends of the

spit cup mounting plugs out

housing covering the carburetor mounting screws.

nose

must move freely.

pliers

6-4)

of

the air filter

if

5-6

Service Section

Remove the throttle cable screw and nut

4.

from the throttle cable mounting bracket.

5.

Detach the carburetor from the engine by

two

removing the

the

two

smaller carburetor gaskets on either side of the carburetor shield. Keep the heat shield/primer bulb bracket for later installation.

6.

Disconnect the fuel line and the primer tube from the carburetor fittings.

mounting screws. Discard

a

751.1.0490.18

Service Section

7

Pull the carburetor assembly down and away from the engine governor clears the hole in the shroud mounting base.

so

the air vane

5-7

SERVICING (cont’d)

Removal (cont’d)

8.

CAUTION:

governor spring during this step.

Slide the white plastic control lever to either

end

of

locked position. This will help restrict its movement while you disconnect the throttle

cable from the control lever.

Disassembly

Tools Required:

Needle Nose Pliers Flat blade screwdriver

Avoid damaging the delicate

its adjustment and snap it to the

1.

At the throat needle nose pliers to gently pull the throttle plate out of the air vane governor assembly shaft. Notice the orientation of the small protrusions on the throttle plate as you pull it out. The single protrusion should be on your left (next to the hole at the position).

2.

Remove the retainer holding the speed control lever.

of

the carburetor, use the

9

o’clock

5-8

751.I.0490.3

Service Section

751.I,0490.2

3.

Hold the governor collar on the carburetor and lift the air vane/throttle shaft out of the carburetor. Lift the collar and spring up, detaching the spring from the speed control

lever.

4.

Turn the carburetor over and remove the

four bowl retaining screws, the bowl gasket and the bowl. Discard the bowl gasket.

5..

Remove the fuel filter from the fuel nozzle.

HINGE

6.

Remove the float hinge pin, the inlet valve

needle assembly (with its clip) and the float. Discard the needle and clip.

7.

Inspect the float for cracks or deterioration

of

the cork.

Service

Section

5-9

SERVICING

Disassembly (cont’d)

8.

Remove the brass inlet fuel valve seat and discard.

9.

Remove the nozzle and the high speed jet

from the nozzle.

Cleaning and Inspection

1.

With the carburetor completely disassembled, thoroughly clean all parts; do

not soak the parts, use an aerosol

carburetor cleaner. Inspect for wear or

deterioration. Blow dry all carburetor passages with compressed air.

CAUTION:

enlarge or restrict any passageway in the carburetor.

2.

Always check the carburetor mounting

flange and fuel bowl mounting flange

surfaces to be sure they are flush.

(cont’d)

If

a tag wire is used, never

Assembly

Tools

1.

2.

3.

5-10

Required

Flat blade screwdriver Needle nose pliers

Install the high speed jet into the fuel nozzle. Turn the carburetor over and install the nozzle assembly into the carburetor body. Install a new brass inlet fuel valve seat.

Service Section

4.

Install a new inlet valve needle and clip on

the float.

5.

Install the float assembly with a new float hinge pin in the bottom Ensure the hinge pin is positioned properly

to

keep the float level. The float should be free to move up and down easily in the carburetor body.

6.

Adjust the float

so

17/32" (11.9 13.5

flange (without the gasket in place) to the top of the float.

of

the carburetor.

the height is

mm) from the bowl

15/32"

to

4

7.

Install the fuel filter over the nozzle. Install a new fuel bowl gasket and the fuel

8.

bowl with the four bowl retaining screws.

Service Section

5-11

SERVICING

(cont'd)

Hook the governor spring into the bottom

9.

the governor collar.

Install the air vane and throttle shaft into the

10.

carburetor body by very carefully pushing the shaft through the collar into the carburetor body.

11.

Push the throttle plate into the throttle shaft (the plate only inserts one way).

of

12.

13.

5-12

Holding the spring collar, hook the other

of

the spring into the speed control

end arm.

Re-install the speed control lever and retainer.

Service

2

Section

Installation

Tools

Required: See "REMOVAL"

Install new gaskets and the heat shield (removed in previous procedure) on the

carburetor. The air cleaner element and its

cover should not be in place at this time.

Guide the air vane through the opening in the shroud base and attach the carburetor to the engine with the Torque to

Replace the spit cup, if used. To prevent

any air leaks make sure the spitcup

plugs) is

Insert the the vertical tab of the speed control lever.

Set the throttle to fast and the speed control

lever the full open position.

Install the fuel line and primer tube on the appropriate carburetor fittings.

Check that the choke/air vane assembly

moves freely.

Install the air filter and cover.

45-55

(are)

seated properly.

Z

bend of the throttle cable into

so

the throttle plate is sprung open to

in Ibs

two

mounting screws.

(5.1

-6.2

N-m).

(

or

two

TOOLS REQUIRED:

Tachometer

NOTE: Each "click" of the governor collar represents approximately

1.

Turn the collar clockwise to increase spring tension, and engine RPMs, or counter clockwise to decrease them. Preset the governor collar

751.1.1207.33

Service Section

Presetting the Governor

50

RPMs.

3

or 4 clicks clockwise.

5-13

SERVICING

2.

Use the tachometer to check engine speed;

the normal high speed setting is

3050

Servicing the Air Filter

1.

To remove the air filter, unsnap the wire

holder, on the left side, from the cover.

Then unsnap the cover from the clear

plastic shell. Remove the cover and air

filter element.

2.

Clean and re-oil the air filter element according pages

CAUTION:

filter element, with a dry filter element, or without the spit cup (or carb access hole plugs) in position (unfiltered air could enter the carburetor) or engine life will be shortened.

(cont'd)

150

RPM.

to

the maintenance procedure,

4-3

and

4-4.

Do

not operate the engine without a

5-14

Service Section

QUICK REFERENCE SECTION

Specifications

Special Tool Requirements.

Troubleshooting

Maintenance

SERVICE SECTION

Primer Start Carburetor.

Fuel system

Ignition System

Rewind Starter.

Engine

Pivoting Zone Start Brake.

Appendix

Service Section

6-1

OPERATION..

Fuel Tank 6-3 Fuel Cap 6-3

6-3

SERVICE

Fuel Cap 6-4 Tank Removal 6-4 Cleaning 6-5

Tank Installation 6-6

Fuel storage 6-6

6-4

6-2

n

Service Section

OPERATION

Fuel

Tank

The Toro V Engine uses a with a non replaceable screen. The filter is welded in the bottom of the tank over the outlet fitting. The tank is mounted above the level of the carburetor and uses gravity to supply fuel through a carburetor. The fuel hose is friction fitted to the tank outlet at one end and to the carburetor at the other end.

The fuel tank is vented through an opening

fuel cap. The fuel opening on the tank is mm) in diameter and is opposite the fuel outlet. This helps prevent damage to the filter screen by funnels and gasoline filler spouts that may be inserted into

the fuel tank during refilling. The placement of the

cap also prevents interference with the starting rope in zone start applications.

.25"

I.D.

1.3

quart plastic fuel tank

75

micron, intank, filter

(6.35

mm) rubber hose to the

in

1.75"

the

(45

The fuel cap sealing disc that is vented to a baffle assembly in the body of the cap. The baffle assembly allows expansion in the tank without the Atmospheric pressure is allowed into the tank from an opening in the cap to allow gravity to feed fuel to the carburetor. cap fails, the entire assembly must be replaced.

751.I0490.55

Service Section

Fuel

is

a four piece design with an inner

loss

of fuel.

NOTE:

If

an individual part of the

Cap

6-3

SERVICE

Tank

Removal

Tools

Required

Clamping Pliers

Minimum

#T25

1.

Disassemble the starter rope

sufficiently to untie (or cut) the starter rope

knot and release the rope from the handle

(

the plastic rope-stop prevents the rope

from rewinding completely into the starter).

Tow

1.5

Qt (1.41ltr)Container

“T”

handle

NOTE: To remove the fuel tank, you may either crimp the fuel hose and use the clamping pliers

to remove the fuel hose from the carburetor.

Release the clamping pliers and drain the fuel

into a container designed

to

receive gasoline.

OR

You may reach under the edge of the fuel tank to pull the hose off the tank outlet, but you must be ready to catch the fuel that will drain out of the tank. a container large enough to hold the amount of fuel in the tank.

6-4

If

you use this method, you must have

Service

Section

CAUTION: Avoid fire and explosion. Store fuel in a container designed for gasoline and never

smoke while working around gasoline.

If

you remove the fuel line from the tank outlet catch the fuel as it drains. Properly dispose of the fuel.

Note:

Always use a fresh supply of fuel

when refilling the tank.

In

Tank Filter Screen

751.1.0490.63

751.1B490.84

Using a three screws, with captive washers, that secure the fuel tank to the shroud assembly.

Take the fuel tank

and wash the tank with a clean, cleaning solvent intended for engine parts.

NOTE: carburetor cleaner.

Back flush the filter screen by directing the

cleaning solvent, under moderate pressure, through the sediment reservoir and screen,

opposite the direction of fuel flow. As a final rinse, wash the tank again with

cleaning solvent or a small amount of fresh

fuel..

Clean or replace the fuel hose.

#T25

TORX

driver, remove the

to

an appropriate area

mild

Do

not use soap and water or

Cleaning

Service Section

6-5

SERVICE

Tank Installation Tools required:

1.

2.

3.

Fuel Storage

Use clean, fresh, lead-free gasoline, including

oxygenated

octane rating of freshness, purchase only the quantity of

gasoline that can be used in lead-free gasoline results chamber deposits and longer spark plug life. Use of premium grade fuel is not necessary or recommended.

(cont’d)

#T25 Tom

Fasten the tank to the engine with the three screws, with captive washers.

Connect the fuel line. Refill the tank with a fresh gas/oil mixture and check the system for leaks.

or

reformulated

85

or higher. To assure

gasoline, with an

30

days.

Use

in

fewer combustion

of

Follow

Proper

Procedure For

Fuel Storage

Important::

containing Methanol, gasoline containing more than

10%’

than

15%

engine/fuel system damage.

Never use Methanol gasoline

ethanol or gasoline containing more MTBE. Use of these fuels can cause

6-6

Service Section

QUICK

Specifications

REFERENCE SECTION

Special

Troubleshooting

Maintenance

Tool

Requirements.

SERVICE SECTION

Primer Start Carburetor.

Fuel

Ignition System

System

7

Rewind Starter.

Engine

Pivoting Zone Start Brake.

Appendix

Service Section

7-1

I

TROUBLESHOOTING

Process

7-3

/-

SPARK PLUG

Operation Service

CD

PACK

Advantages Operation Air Gap Adjustment Removal/lnstallation

FLYWHEEL

Operation

Removal Installation

7-4

7-4 7-4

7-4

7-4 7-5 7-6 7-6

7-6

7-6 7-7

7-8

7-2

Service Section

TROUBLESHOOTING

Process

Check the ignition system in the following order:

Spark plug (connection and wire condition) CD Pack (air gap, connections or spark) Flywheel (key and magnets)

Use the following table to aid in diagnosing the

problem

Cause

Spark plug wire loose

engine dies.

(NOTE:

symptoms may also be caused by fuel high tension lead loose

These

symptom problems).

Spark plug in poor conditionCD Pack air gap wrong

~-

Adjust (see CD Pack Service

section)

Secure with-G-E silicon Clean and tighten leads Replace-CD Replace key and check keyway

(see Flywheel Servicing, chapter)

Replace flywheel

Pack

in

this

Service Section

7-3

SPARK

Operation

The spark plug ignites the fuel-oil mixture by top dead center (TDC).

constructed as shown.

PLUG

producing a spark just before the piston reaches

A

spark plug is typically

METAL

SHELL

HEAD

INSULATOR

7

Service

Check the spark plug with the chart and

1.

replace, specifications shown.

CAUTION:

blaster.

2.

Remove carbon build up by cleaning the plug with a wire brush. Check the condition

of

Replace if necessary.

if

necessary using the

Do

not clean the plug with a sand

the

plug for cracking or damage.

GROUND

ELECTRODE

COPPER

LEG

INSULATOR

CORE

GAP

751.2.5130.809

CD

PACK

Advantages

The Toro V Engine uses a solid state ignition

module to generate an electrical pulse for the spark plug. The term ’solid state” is a broad term applied to any electrical system which uses electronic components such as diodes, transistors, silicon controlled rectifiers etc., that take the place of one or more of the older standard mechanical ignition components.

7-4

(SCR),

Service Section

Solid State Ignition

uses Electronic

Components

In Place

Of

Mechanical Devices

Electronic components are very small, have no moving parts, require no mechanical adjustments, and are not affected by wear as are mechanical devices. They deliver uniform performance throughout component life under adverse operating conditions. They can be hermetically sealed they are unaffected by dust, dirt, oil

or

so

moisture.

that

The Capacitive Discharge (CD) system is breakerless, and contains electronic components that replace mechanical points and related accessories (such as a breaker cam, spark advance assembly, etc.).

_I__~

751.2.5130.810

Operation

As the flywheel magnet passes the CD pack, an AC voltage is induced into the charge coil. This AC voltage which is then stored in a capacitor.

When the SCR is triggered or “fires”, up to

DC, stored in the capacitor, travels to the spark coil. Here

is discharged across the electrodes of the spark Plug-

At slower speeds, the flywheel magnet induces a smaller charge triggers the SCR, enabling easier starting “retarded firing position” about 5 degrees before top dead center (BTDC).

is

converted by a rectifier into a DC signal

it

is stepped up to as much as

in

the trigger coil. This action

25,000

200

volts

volts and

in

a

AT 5”

BTDC

CRANKSHAFT

AT

25”

BTDC

MAGNET

751.2.5130.812

Service

At faster speeds (about

800

RPM),

the flywheel magnets induce a large enough charge in the trigger coil to trigger the SCR in the “advanced firing position” (about

25

degrees BTDC).

Section

7-5

CD

PACK

Air Gap Adjustment

Tools

1.

2.

Removal/Installation

Tools Required

(cont'd)

required:

Air Gap Gauge (p/n 604659)

10

mm Socket Rotate the flywheel until the magnets are directly adjacent to the Adjust the air gap by loosening the screws, inserting the gauge or a piece

(.254 mm) shim stock, and tightening the screws.

1Omm

Socket

Flat blade screwdriver

CD

Pack as shown.

of

.010"

1.

Disconnect leads and remove the mounting

screws.

2.

Remove the screws, replace the and set the gap as outlined in the previous

topic. Torque the screws to

Nm).

100

CD

Pack

in. Ibs

(11

FLYWHEEL

The flywheel is connected directly to the crankshaft (secured by a key and nut) and turns at the same speed as the crankshaft. Two

permanent magnets, imbedded in the flywheel, rotate past the coil in the generation of electricity.

Imbedded in the opposite side of the flywheel are steel counter weights which offset the weight

of

the magnets. These counter weights are not

magnetic.

CD

Pack to begin the

7-6

.1.1207.10

Service Section

Tools

Required Piston Stop (p/n 677389) Puller

(B&S

#19165) or similar puller

Soft

Hammer

1/2” Socket

1.

Remove the spark plug and install the piston stop.

2.

Remove the shroud and fuel hoses.

3.

Remove the flywheel nut.

Removal

Service Section

7-7

FLYWHEEL

Removal (cont'd)

5.

Remove the key and check its condition.

6.

Replace the crankshaft and/or flywheel the keyway is distorted or cracked. Replace the key if damaged.

7.

Check the flywheel for wear and flywheel magnets for strength. Check the magnets by holding the flywheel up against a metal object. The magnets shouldhave a strong pulling force.

Installation Tools

Required:

1/2"

Socket

1.

Make sure the flywheel keyway is absolutely clean.

2.

Make sure the key is installed parallel with the centerline of the crankshaft.

(cont'd)

if

3.

4.

7-8

Locate the keyway cutout in the flywheel

over the key and shaft. Torque the flywheel nut to

(43-47

Nm).

375-425

in.

Ibs

Service Section

QUICK REFERENCE

Specifications

Special Tool Requirements.

Troubleshooting

Maintenance

SECTION

SERVICE

Primer Start Carburetor.

Fuel system

Ignition System

Rewind Starter.

Engine

Pivoting Zone Start Brake.

SECTION

8

Appendix

Service

Section

8-1

Operation

The rewind starter operates through a

retainer/friction disc that causes two, spring-loaded, engagement dogs to extend from the rewind starter and engage the inside of the

starter hub on the flywheel. The engagement dogs extend outward to make contact with the starter hub when the rope is pulled. When the

engine starts, and the rope is released the starter dogs are retracted back into the center of the rewind mechanism, disengaging them from the starter hub.

Recoil Assembly Replacement

If the starter should wear out, or fail, the complete recoil and blower housing assembly must be replaced (the exception to this is the starter rope). You should not attempt to replace

Starter Rope Replacement

Rope

length:

When installing the replacement rope use

1

1/2

turns of prewind to pretension the spring

(enough to pull the rope back into the recoil).

88

5/8"

1/2

to

Service Section

QUICK REFERENCE SECTION

Specifications

Special

Troubleshooting

Maintenance

Tool

Requirements.

SERVICE SECTION

Primer Start Carburetor.

Fuel system

Ignition System

Rewind Starter.

Engine

Pivoting Zone Start Brake.

Appendix

Service

Section

9-1

ADVANTAGES DESCRIPTION 9-3

OPERATION 9-3

SERVICE

Cylinder/Crankcase Halves 9-5 Oil Seals 9-5 Core Muffler Baffle 9-6 Exhaust Ports 9-7 Carburetor Gaskets 9-7

REMOVAL 9-7

DISASSEMBLY 9-11

INSPECTION AND REPAIR 9-12

REED VALVE SERVICE

REASSEMBLY 9-14

Reinstalling External Components 9-17

TIPS

Plugs

9-5

9-6

P

9-2

Service

Section

REED

VALVE

ADVANTAGES DESCRIPTION

Two-cycle engines have special advantages which

make their use more practical in certain applications. Two-cycle engines are lightweight with an excellent power-to-weight ratio and can be operated in any position. They are also notably easy to maintain and service because of their uncomplicated design.

REED

FIRST

STROKE-

STROKE

The Toro Two-cycle

V

Engine used on Toro rotary mowers is a reed valve design. This design name describes the method used to control the admission of the fuel/air mixture into the cylinder/crankcase and combustion chamber, and the exhausting of gases.

OPERATION

The two-cycle engine is one of the simplest and

most efficient power systems ever developed.

The illustration show at the left shows what happens

inside the engine during one full crankshaft revolution. Fuel intake, fuel ignition and the exhaust

of burned gases all take place during a single 360-degree rotation of the crankshaft.

REED

VALVE

CLOSED

EXHAUST GASES

EXHAUST

GASES

751.2.5130.814

Beginning at a point where the top of the piston is

just below the exhaust port, the piston moves down

toward the crankcase. uncovered, the fuel/air mixture stored in the pressurized crankcase is forced into the combustion chamber.

751.2.5130.815

Service Section

As

the transfer port is

9-3

OPERATION

(cont'd)

The crankshaft continues its rotation and the piston begins its travel toward the spark plug. it moves, the piston seals

off

the transfer port first, then the exhaust port. When both ports are sealed, the remaining travel compresses the air/fuel mixture to prepare it for ignition. The travel of the piston towards the spark plug is called the compression stroke.

The movement of the piston towards the spark plug also has an important effect in the crankcase. Once the transfer port is sealed, a vacuum

is

created in the crankcase. This action pulls the reed valve open and draws in a fresh charge of the fuel/air mixture.

Just before the piston reaches top dead center

(TDC), the spark plug fires. When the engine is functioning properly, the fuel/air mixture ignites, causing a burn that occurs evenly through the

power stroke. The piston changes direction and

begins its travel towards the crankcase.

NOTE:

If

the compression ratio is too high, the

fuel/air mixture actually explodes before it is

ignited by the sparkplug. This can be heard and

is identified as detonation (also called "knock").

As

REED

VALVE

REED

VALVE

CLOSED

\

When the piston opens the exhaust port,

high-pressure exhaust gases exit the exhaust port. Further movement of the piston towards

the crankcase uncovers the transfer port which

allows a fresh charge of air/fuel mixture to enter

the combustion chamber.

As

the exhaust gases continue to exit the exhaust port the engine is readied for another cycle.

9-4

Service

REED

VALVE

CLOSED,

I--

Section

EXHAUST GASES

SECOND

_-

751.2.5130.817

STROKE

751.2.5130.818

The two-cycle engine is always well lubricated as

long as the correct gas/oil mixture(using proper 2 cycle oil) is maintained in the fuel tank. Oil suspended in the fuel vapor adheres to all moving

parts, keeping them continually coated, regardless of operating angle.

751.I.0490.2!

SERVICE

Cylinder/Crankcase Halves

The

two

halves are a matched pair and cannot be mixed. Check the cleaning and assembly procedures under Engine -Disassembly (pg 9-11) in this section.

Be sure to use Loctite cover only. Do not apply gasket maker to either crankshaft seal. Torque the that secure the two halves to 105-115 in. Ibs (12 Nm).

Visually inspect for leaking or damaged (two locations).

515

gasket maker on the

4

washer-head screws

oil

Oil

seals

TIPS

13

Seals

Service

Section

9-5

SERVICE

Core

Visually inspect for damaged or leaking plugs

TIPS

Plugs

(con’t)

Muffler

This item should be cleaned every

(maximum) exhaust system (power

the engine (piston scoring).

Muffler Plate Screws Screws may have loosened due

They should be torqued to

(16

Baffle

22Nm

50

to

keep carbon from clogging the

loss)

and from entering

to

vibration.

140

200 in. Ibs

hours

751.1.12071

9-6

Service Section

Exhaust

Ports

Exhaust ports should be inspected every

and cleaned as necessary.

Carburetor Gaskets

Ensure that the air cleaner/carburetor mounting screws are tightened to a torque of

(5.0

6.1

Nm). Check for damaged or leaking gasket surfaces. Replace the gaskets if damaged. Carburetor gaskets on either side of the carburetor shield may be leaking or damaged causing air leaks into the engine (may cause power fluctuations).

45-55

50

hours

in. Ibs

Removal

Tools Required:

Sockets screwdriver

Flywheel puller

Prior to disassembling the engine and prior to further

troubleshooting a malfunction, separate it from the mower as follows:

1.

Disconnect the spark plug wire

2. Disassemble the the knot

\

rope-stop will keep the rope from rewinding completely into the starter.

Service Section

3/8"",

5/16"", 7/16"',

Torx

'T'

starter handle

in

the starter rope. The plastic

Flat1/2” blade

to

untie

9-7

REMOVAL

Remove the fuel tank (See Fuel Tank

3.

Removal, page 6-4).

4.

Remove the shroud the starter comes

with the shroud.

5.

Remove the flywheel (See Flywheel Removal, page

(cont'd)

off

7-7).

6. Remove the remaining bolts securing the shroud base to the crankcase halves.

9-8

-__I-

Service Section

751.I,0490.80

751.1.0490.13

7.

Remove the brake plate assembly by removing one one

3/8"

assembly on the mower deck and

disconnect the ground wire that goes to the

CD Pack. Remove the CD Pack ( See CD Removal,

8.

page

7-6).

9.

Snap open the air cleaner cover (catch on

left, hinge on right) and remove the air filter element. Pop out, and retain, the

plugs (or spit cup) covering the carburetor screws. Remove the the carburetor to the engine

production

place of the carburetor spitcup by pulling the ends out of the carburetor access holes molded into the air filter base. Disconnect the fuel line from the carburetor. Separate the carburetor from the engine with controls attached and set it on the mower deck. (See Carburetor

Removal, page

10

mm shoulder screw and

washer-head screw. Place the

2

plastic

two

screws securing

NOTE:

'95

carburetors use a spit cup in

2

plugs. Remove the

5-5)

Later

Service

10.

On

self

the

5/16"

cover. Remove spacers that secure the belt drive guide

bracket to the transmission. Remove the

drive belt from the pulley. The belt will stay with the engine as the cover is removed.

Section

propelled

screw

to

two

models

remove the belt drive

3/8"

only,

remove

screws with

9-9

Remove the

11.

the blade, blade retainer and accelerator to the engine shaft. Use heavy duty gloves to

hold the blade while removing the nut. Set

the parts aside

12.

7/16-20

blade bolt that secures

Tools Required

Compression Pliers (p/n Wrist Pin Knockout Tool TOW Flat blade screwdriver

1.

Remove the four crankcase cap screws with a TOW halves using a screwdriver.

9-10

E-12

303857) (602884)

E-12

socket and separate the

Service

Section

2.

Remove the entire crankshaft assembly and discard the oil seals.

Carefully remove the head) cap screws rod cap and the split bearing liner. The needle roller bearings are under the split bearing liner and will be loose. Careful account for all of them.

HSH

(hex socket

to

remove the connecting

32

r

3.

Remove the piston and rod assembly;

separate the assembly,

a

compression pliers on the retaining ring.

Use the wrist pin knockout tool to punch out

the wrist pin.

if

necessary, using

INSPECTION AND REPAIR

Tools

Required: Gel Seal and Gasket Remover Screw Lock (p/n

1.

Check bearings for wear and freedom of movement; replace

682301)

if

questionable.

9

Service Section

9-11

INSPECTION AND REPAIR (CONT'D)

2. Check rings for sticking. Remove and check rings for wear (e.g. ring end gap) or damage; replace the rings if questionable.

3.

Clean and inspect the piston, including the ring land and wrist pin snap ring grooves. Check all parts for wear or damage and replace

4. Clean the crankcase surfaces with Gel Seal and Gasket Remover.

if

questionable.

5.

9-12

Check that the ring end gap is between .006" and .016"(.152 .406mm) with (.762mm) as the wear limit.

.030"

Service

Section

.006”

(.152mm .406mm)

,016"

6.

Replace the core plugs

Screw Lock on the outside surfaces.

if

leaking, using

CAUTION:

with a drill bit.

Do

not attempt to clean any

hole

REED VALVE SERVICE

Tools

&

Supplies Required: Loctite 271 Carburetor Solvent Feeler Gauge

These assemblies permit fuel mixtures to enter the crankcase on the compression stroke and to trap fuel mixture in the crankcase on power strokes.

Check the clearance between the tip of the reed and the plate; replace the reeds if the

clearance is more than

.004"

(.l mm).

751.I.0490.34

751.1.0490.34A

Service Section

Clean the reeds carefully, by hand, using carburetor solvent

CAUTION:

air

to

cause distortion. When replacing the reeds, install with the

smooth edge down and use Loctite 271 on the thread of the screws.

clean

Do

the

not

reeds.

use

compressed

High

pressure will

9-13

REASSEMBLY

Tools & Supplies Required

Loctite 271 Loctite 515 Gasket Maker Piston Stop (p/n 677389) Ring Compressor (p/n 609967) Seal Driver (p/n 608976)

1. Secure the wrist pin using the snap ring. Make sure the square edge of the snap ring faces out and the ring opening faces up

of

(toward the top

2.

Install the pressure back piston ring in the top groove with the bevel facing up; The square cut ring goes second and has no top or bottom orientation. Stagger the ring

gaps.

CAUTION:

piston from traveling too far up into the cylinder.

If

the piston goes to far into the cylinder the only

way to remove it from the cylinder is

piston.

Use the piston stop to prevent the

the piston).

to

break the

3. Assemble the rod cap. Ensure that the dovetail ends of the liner are matched. Install new needles (pin 683911).

NOTE: One side of the paper is sticky; remove the paper carefully while installing the needle bearings. There should be needle bearings on the lower connecting rod.

9-14

32

Service Section

4.

Lubricate and assemble the needle bearings

to the crankshaft and install the crankshaft.

751.1.1207.26A-

Service

6.

Oil

the parts and

ring compressor to install the piston with the

“BTM” NOTE:

some engines. However the small “rectangle” should still be visible through the

ports.

Section

use

the piston stop and

mark facing toward the exhaust ports.

The letters

“BTM”

were omitted

on

0-15

REASSEMBLY

7.

Thinly apply Loctite

1104

gasket maker sealing surface. Be careful not to get sealant on the bearings or seals. Carefully align the

8.

using the alignment pin and its matching hole; press the

9.

Torque the hex washer-head screws to a total of the screws in increments

(2.26

crankshaft turns freely.

110

Nm ) while checking that the

(cont’d)

515

to

two

halves together.

in. Ibs

(12.5

or Three Bond

the crankcase cover

crankcase halves

NOTE: Tighten

of

20

in Ibs

10.

11.

9-16

Install new oil seals. Always use new seals and lubricate new seals, with oil before pressing them into place with the seal driver. Use the seal driver to do this.

CAUTION:

crankcase cover with the seals in place.

Install the shroud base.

Do

on

the

ID

only,

not assemble the

Service

Section

751.1.0490.28

Reinstalling External Components

12.

Reattach the flywheel brake system.

13.

Clean the crankshaft and flywheel hub and install the flywheel (see flywheel installation,

7-8).

page

14.

Install the carburetor and governor assembly (see page

5-11).

~-

751.1.1207.15

Service Section

15.

Install the starter and shroud assembly and starter handle (see page

9-7).

Reconnect the fuel lines and electrical system leads.

Test run the engine.

9-17

QUICK REFERENCE SECTION

Specifications

Special

Troubleshooting

Maintenance

Tool

Requirements.

SERVICE SECTION

Primer Start Carburetor.

Fuel system

Ignition System

Rewind Starter.

Engine

Pivoting Zone Start Brake.

Appendix

Service Section

10-1

INTRODUCTION.

10-3

OPERATION.

DISASSEMBLY

ASSEMBLY

10-3

10-4

10-6

Service Section

2

Primary Safety Criteria

1

Two-step Operation to

start

2.

Blade stops in three

seconds

INTRODUCTION

In

1982

the federal government mandated that all

consumer walk behind mowers with a cut of

(63.5

cm) or less, be equipped with a safety blade stopping device. There are two primary criteria which these devices must meet:

A

two-step operation must be performed in

order to start the blade rotating. The blade must come to a stop within three

seconds of the operator leaving the operator's position.

One of the ways the Tor0 Company met these

requirements was with the “zone start system." This system utilizes a kill switch and a brake which stops the engine when the operator releases the blade control bail. The two-step blade criteria is met by

requiring the operator to pull the bail to the handle first, then pull the recoil rope from the operator's position.

25"

Service

OPERATION

The pivoting style zone start brake system has two main functions. The first function of the system is to stop the production of spark and the second is to stop the engine and blade.

Stopping spark production is controlled by a switch. The switch is closed when the blade control bail is in the "at rest" position. Raising the bail to the main mower handle opens the switch.

Section

10-3

OPERATION (cont'd)

Switch leads are connected to the primary side of the coil and to the ground. When the switch

is closed, coil is grounded. This action prevents the coil from producing the high voltage necessary to generate spark. When the switch is open, the ignition coil produces spark.

Stopping the engine and blade is accomplished

of

by means bottom of the flywheel. The brake spring is in the "braked" position when the blade control bail is

in the "at rest" position. When the blade control

bail is raised to the mower handle, the brake is

retracted from the underside of the flywheel to allow the engine to turn freely. The ignition system will produce a spark when the starter

rope is pulled.

a brake that is applied to the

751.2.5130.819

10

DISASSEMBLY

Tools

Required:

10mm

2

Self-tapping screw

3

Brake switch leadwire

4

Ground strap

5

Insulation strap

6

Plastic rivet (self expanding)

7

Shoulder screw

8

Brake assembly

9

Screw

10

Brake Mounting plate

Socket

(10

mm)

(2)

Service

Section

1.

If

the engine and blade are taking more than

3

seconds to stop when the blade control

bail is released, inspect the brake pad for

if

excessive wear and replace Note that the brake pad and the brake plate are replaceable only as an assembly.

Disconnect the cable from the control bail on the handle

2.

To

reduce the pressure of the spring between the brake mounting plate and brake plate, squeeze the tabs of the brake

cable that hold

mounting plate. Push the cable through the hole in the brake mounting plate.

it

in place at the brake

necessary.

751.1.0490.70

Service

3.

Slide the cable out through the horizontal slot in the brake mounting plate. the ball end of the cable up through the vertical slot in the brake plate.

Section

Also,

slide

1

0-5

DISASSEMBLY

4.

Remove the 10 mm shoulder screw to remove the brake plate and brake pad

attached to

5.

If the ground strap or any part assembly requires replacement, remove second screw to remove the brake mounting plate from the engine.

ASSEMBLY

Tools Required

10mm Needle

If

1. removed from the engine, simply reconnect the grounding lead to the push-on terminal directly above the ground strap stop and continue with the reassembly process.

NOTE:

removed, torque the screw to 60 70 in. Ibs (6.78 -7.91 Nm).

Sockets

nose

the brake mounting plate was not

If the brake mounting plate was

(cont’d)

it.

Pliers

of

/7

this

the

2.

10-6

Secure the replacement brake plate to the

it

engine with the shoulder screw. Torque 90 in Ibs (9.2 Nm). Ensure that the brake plate pivots freely.

photo

only)

(shroud removed for

to

Service Section

._

Slide the cable into the narrow slot on the

3.

brake mounting plate and then push the cable into the hole making sure the tabs lock into the bracket.

4.

One end hook shape to it; that end hooks over an indentation in the brake plate. Squeeze the compression spring and slip it over the cable between the brake mounting plate and brake plate.

of

the compression spring has a

751.1.0490.70

751.I,0490.88

Service

5.

Reattach the cable to the control bail on the handles

Section

10-7

ASSEMBLY

(cont’d)

Insert the ball end

6.

vertical slot Operate the blade control bail to verify that

7.

the brake mechanism stops the blade within three seconds. There is no adjustment needed after this assembly process is completed

of

the cable into the

of

the brake plate.

10-8

Service

Section

QUICK REFERENCE SECTION

Specifications

Special

Troubleshooting

Maintenance

Tool

Requirements.

SERVICE SECTION

Primer Start Carburetor.

Fuel system

Ignition System

Rewind Starter.

Pivoting Zone Start Brake.

Appendix

11

A-1

Table

Power Head - Exploded View.

.

Ignition and Exhaust

Exploded View

Of

Contents

...............................

........................

n

A-3

A-4

Starter and Primer Start Carburetor

Primer Start Carburetor Assembly

.

Exploded View.

...........

............

A-5

A-6

n

A-2

Appendix

-

Power Head - Exploded View

U

5

Ref.

20

I

15

3

11

1 - Oil Seal (2)

2

-

Upper Main Bearing (Narrow)

-

Split Liner (2)

3

-

Bearing

4

5

-

Connecting Rod Assembly

6

-

Retaining Ring

7

-

Wrist Pin

-

Piston

8

-

Piston Ring

9

-

Top Piston Ring

10 11

-

Cylinder & Crankcase Assembly

1

12 - Core Plug 13 - Dowel

-

Needle Bearing (Wide)

14 15

-

Slotted Head Screw (2)

-

Reed Backup Plate

16

-

Carburetor Reed

17 18

-

Washer Head Hex. Screw

19 - Crankshaft

20

-

HSH Cap Screw (2)

-

Needle Bearing (32)

21 22

-

Sealant (Not Illustrated, See Required Service Supplies)

(4)

Appendix A93

Ignition and Exhaust - Exploded

View

19

18

17

16

1 - Shoulder Screw

-

Brake Plate Assembly

2 3

-

Screw

4

-

Brake Mounting Plate

5

-

Hex. Washer Head Screw (2)

-

CD ignition Pack

6

7

-

Spark Plug (Champion RJ12C)

8

-

Exhaust Gasket

-

Muffler Cover

9

10

-

Screw (3)

-

Baffle

1 1 12

-

Screw

-

Muffler Plate

13

-

Ground Strap Stop

14

-

Self-tapping Screw

15

-

Brake Switch Leadwire

16

-

Ground Strap

18

-

Insulation Strap

-

Self-expanding Plastic Rivet (2)

19

..

(4)

1

n

12

11

10

Starter and Primer Start Carburetor - Exploded View

20

19

r'\

1

-

Shroud Assembly

2

-

Screw

3

-

Nut

4

-

Lockwasher

5 - Starter Hub

6

-

Flywheel Assembly

-

Shroud Base

7 8 - Key

9

-

Carburetor Gasket

10

-

(4)

(2)

Carburetor Heat Shield & Primer Mount

11 - Primer Bulb

12

-

Primer Body

13

-

Primer Hose

14

-

Fuel Shield

15

-

Air Filter

16

-

Air Filter Cover

-

Screw

18 - Carburetor Assembly

-

Screw

19

20 - Rope

(2)

(3)

16

Appendix

A-5

Primer Start Carburetor Assembly Exploded View

I

n

i

1 Screw

5

Gasket 6 Main Nozzle 7 Filter Screen

8

9

Carburetor Bowl

10

11 Float Pin 12 Main Jet

(2)

Float

Screw (4)

6

7

13 Retainer 14 Inlet Needle

15

Inlet Seat 16 Carburetor Body 17 Throttle Plate

Throttle Spring

19 Air Vane Collar

20 Air Vane 21 Cable Bracket

22 Lever 23 Retainer

10

i

A-6

Appendix

Carburetor

Troubleshooting 5-3

Engine Starts Hard 5-3 Engine Runs Rich 5-3 Engine Runs Lean 5-3 Fuel Leaks From Carburetor 5-3

Introduction 5-4

Identification 5-4 Operation 5-4 Governor

Servicing 5-5

Removal 5-5 Disassembly 5-7 Cleaning and Inspection 5-9 Assembly 5-9

Installation 5-1

Presetting the Governor 5-12

Final Check 5-12

5-5

Engine

Advantages Description 9-3 Operation 9-3 Service Tips 9-5

Cylinder/Crankcase Halves 9-5 Oil Seals

Core Plugs 9-6

Muffler Baffle 9-6

Exhaust Ports 9-7

Carburetor Gaskets 9-7

Removal 9-7

9-5

Air Gap Adjustment 7.6 Removal/lnstallation 7-6

Flywheel 7.6

Operation 7.6 Removal 7.7

Installation 7-8

Maintenance

Air Filter 4.3

Cleaning 4.3

Spark Plug 4.4

Spark lug Gap 4.5 Spark Plug Torque 4.5

Exhaust System 4.5

Cleaning 4.5

Reassembling 4.7

Rewind Starter

Operation 8.2

Recoil Assembly/Replacement 8-2

Starter Rope Replacement 8-2

Specifications

Engine Specifications 1-3 Engine Fastener Torque Requirements 1-4

Carburetor Specifications 1-4

Tool requirements

2-2

Troubleshooting

Engine Will Not Start When “cold“ 3-3

Disassembly 9-1 Inspection And Repair 9-12 Reed Valve Service 9-13 Reassembly 9-14

Reinstalling External Components 9-17

Fuel System

Operation

Fuel Tank Fuel Cap 6-3

Service 6-4

Fuel Cap 6-4 Tank Removal 6-4 Cleaning 6-5 Tank Installation 6-6

Fuel Storage 6-6

6-3 6-3

Ignition System

Troubleshooting 7-3

Process 7-3

Spark Plug 7-4

Operation 7-4

Service 7-4

CD

Pack

Advantages 7-4

Operation 7-5

7-4

Engine Will Start When “cold. But Not When “hot” 3.3

Engine Will Not Produce Spark 3.3 Engine Backfires 3.5 Engine Overheats 3.5 Engine Vibrates Excessively 3-5 Engine Crankshaft Will Not Turn 3-5 Spark Plug Fouled 3.7

Zone Start Brake

Introduction 10-3

Operation 10-3

Disassembly 10-4

Assembly 10-6

Toro 20441, 20442, 20708, 20709, 20710 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Cleaning

Reassembling

Fuel Leaks From Carburetor

INTRODUCTION

Identification

Governor

SERVICING

OPERATION

SERVICE

Cleaning

Fuel Storage

TROUBLESHOOTING

Process

Operation

Service

Advantages

Operation

Air Gap Adjustment

FLYWHEEL

Removal

OPERATION

Cylinder/Crankcase Halves

Carburetor Gaskets

Removal

REED VALVE SERVICE

REASSEMBLY

Reinstalling External Components

DISASSEMBLY

ASSEMBLY

Power Head - Exploded View

Primer Start Carburetor Assembly Exploded View