Toro 51603, 51604, 51630 Service Manual

GAS TRIMMER GUIDE, MODELS 51630, 51603, 51604

Table of Contents – Page 1 of 1

FOREWORD

GENERAL INFORMATION

MAINTENANCE PROCEDURES AIR CLEANER MAINTENANCE EXHAUST SYSTEM MAINTENANCE FLEXIBLE DRIVE SHAFT MAINTENANCE CARBURETOR ADJUSTMENTS -- MODEL TC-1 500 WITH TILLOTSON CARBURETOR ADJUSTMENT -- MODELS TC-300, TC-400 WITH WALBRO

TROUBLESHOOTING AND TEST PROCEDURES

DISASSEMBLY, REPAIR, REASSEMBLY INSTRUCTIONS WALBRO CARBURETOR OPERATION CUTTER HEAD TROUBLESHOOTING CLUTCH REPAIR

GASOLINE POWERED TRIMMER

&

MAINTENANCE

REPAIR GUIDE

MODEL

NO.

51630

1000001

2000001 2000001 & UP

& &

UP

COPYRIGHT(C)

The

MINNEAPOLIS, MN

Tor0

ALL

Company

RIGHTS

55420

RESERVED

-

1982

U.S.A.

Form

492-0266

FOREWORD'

This Maintenance and Repair Guide will provide you

accomplish the maintenance and repair of gasoline-powered flexible line trimmers powered by

the new The number of repair procedures for this line of engine;s has been limited for simplicity and

economy The repairs are easy to accomplish. even for operators or mechanics who have

limited experience Should you require additional information concerning these trimmers.

us Address inquiries to:

General Information

Two-cycle Engine -Theory of Operation

Engine operation Engine Specifications

Engine Torque Specifications

Maintenance Procedures

Air Cleaner Maintenance

Exhaust system Maintenance Flexible Drive Shaft Maintenance Carburetor Adjustments; Model TC-1500 (Tillotson Carburetor) Carburetor Adjustments; Models TC-300 & TC-400 (Walbro carburetor)

Troubleshooting and Test Procedures

Preliminary Checks:

Testing Cylinder Compression Compression Test Procedure Checking For Spark

Checking Fuel Tank Engine Troubleshooting Chart

Checking Fuel Tank Checking the Stop Switch

Disassembly. Repair. Reassembly Instructions

Trimmer Engine Removal. Disassembly. Replacement

Starter Rope Replacement Starter Assembly Replacement

Walbro Carburetor Operation Walbro Carburetor Servicing

Cutter Head Troubleshooting Chart Clutch Repair

Automatic Line Feed Repair

line

of the lightweight two-cycle engines manufactured by The Tor0 Company

in

the repair of small two-cycle engines

TABLE

venting

OF

with

complete information necessary to

The Tor0 Company

8111

Lyndale Avenue South

Minneapolis

Attn.. Service Department

CONTENTS

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

MN

we

urge you to write to

55420

PAGE

1-3

1 1

3 3

4-7

4

5

5-6 6-7

7-9

7 7

7 8

8

9 8

8

10-18

10 12

13 14

16 17

18

GENERAL INFORMATION

Two-cycle

Two-cycle engines are used on TORO Trimmers because of their:

1.

Light weight.

2.

Excellent power-to-weight ratio

3.

Ability to operate

4. Easy maintenance

5. Simple construction

The

TORO

TC-300 and TC-400 Trimmers is a third-port, loop-

scavenged design. This design name describes the path combustion chamber, and the exhausting of spent gases (Fig.

Engine Theory

in

any position

Two-cycle Engine used on the TC-1500,

of

the fuel/air mixture into the crankcase and

1

of

Operation

Engine Operation The piston closes all engine ports as

the combustion chamber (Fig. creates high pressure and partial vacuum

,

2).

The moving piston

in

the combustion chamber

in

the crankcase.

it

moves toward

st Port

\

transfer

(Both

Cylinder)

Figure

In

a loop-scavenged engine flow of the fuel/air mixture can be described as follows: (See Fig.

1.

The fresh fuel/air mixture enters the crankcase through the third-port on The oil

moving parts

2.

The fuel/air mixture is transported through the fuel transfer ports to the combustion chamber where from the engine through the exhaust port.

it

1).

in

the fuel/air mixture lubricates the

within

is compressed, ignited, and then expelled

1

with

a third-port, the

the

side of the cylinder.

the crankcase.

Figure

Compression Stroke

At a point slightly before top dead center (BTDC) of the piston travel, the spark from the plug ignites the fuel air mixture (Fig. port opens allowing the fresh fuel/air mixture to rush into the crankcase to equalize the partial vacuum.

Piston

at or

T.D

Near

Exhaust

Closed

Lubricates

C.

Port

Fresh Fuel/Air Mixture

Moving

3).

Parts

Figure

Ignition

2

Also, at this time, the third-

Spark

Fuel/Air Mixture

Ignites

I

Open

3

1

GENERAL

INFORMATION

The combustion chamber force the piston down the cylinder, closing the third-port and increasing the pressure the bottom of the stroke, the exhaust port opens and the burnt gases begin to be expelled from the combustion chamber (Fig.

banding gases from the burning fuel

e expanding

in

the crankcase. At a point approaching

4).

in

the

Closed

At a point of piston travel slightly before bottom dead center

the

pressed fuel/air mixture in the crankcase to expel the burnt gases and charge the chamber fa

the

(BBDC)

cylinder walls, are uncovered and the com-

enter

following piston stroke (Fig.

the fuel transfer ports, on the sides

is

allowed

the combustion chamber where they help

5).

c

Mixture Compressed

Figure

Power/Exhaust

4

Exhaust/Fuel transfer

Figure

5

ENGINE

SPECIFICATIONS

(Model51630) (Model51603)

Genuine TOR0 Two-Cycle Oil or other high quality two-cycle oil, BIA

TC

TC300

32:1

or

unleaded regular leaded

approved

.40

(13.5

TC400

(model 51604)

oz.)

CooIing~Shroud Carburetor Mounting Screws

Screws

t

Fillotson ModelSP-1A

with

self contained fuel

pump, accelerator pump and filter screen

pump and

Factory adjusted and

Procedures-pp. test run.

filter

screen

Solid state,-capacitive discharge ignition(CD1)

1.29-1.67mm(-051-066 in.)BTDC .20-.30mm (.008-.012

WalbroWa-120series with

self

contained fuel

Factory adjusted and test run.

Adjusting Procedures

22degrees BTDC

in.)

ENGINE TORQUE SPECIFICATIONS

TORQUE-Kg-cm/Kg-m

.35-41Kg-cm

23-35Kg-cm

29-40Kg-cm-15-35

12-23Kg-cm10-20in-lbs

~.TORQUE-in.-lbs/ft-lbs

30-45in.-lbs. 20-30in-lbs

in.-lbs.

NOTE: Metric Torque Conversions:

inch-pounds X1.152= kilogram-centimeters foot-pounds

X

.1383

=

kilogram-meters

29-40Kg-cm 23-35kg-cm

25-35in.-lbs.

3

MAINTENANCE PROCEDURES

AIR CLEANER MAINTENANCE

Check and clean the foam air cleaner element every eight operating hours, and the felt air cleaner once season.

1.

Remove the air cleaner cover by pressing up on

the bottom of the cover to release the lower

mounting tab and pressing

to release the upper tab.

2.

Carefully remove the filter clip or filter retainer.

Remove the foam filter and felt filter (Figures

and

7).

Air Cleaner Housing

in

on front

DO

NOT FORCE.

of

the cover

a

6

5.

Inspect the felt filter. If solvent and air dry of ,damage

6.

Reinstall the felt filter, foam filter, and filter clip or retainer

it

must be replaced.

in

the air cleaner housing (Figures 6 and

it

is dirty, wash

it.

If the filter shows any sign

it

in

7).'

IMPORTANT: Make sure the peg

housing fits through the small hole filter. Both filters must cover the opening air, cleaner housing.

7.

Reinstall the air cleaner cover by pressing the cover

in,

and up, behind the choke lever and then

press the lower mounting tab into the hole engine housing.

DO

NOT FORCE.

in

the air cleaner

in

the

clean

felt

in

the

in

the

Air Cleaner Housing

Felt Filter

Press Here to Remove

Figure

6

EXHAUST

NOTE: Some states require that a spark arrester be attached to the muffler if the trimmer is to be used forested areas, or on other public lands. Be sure to check your local state laws before using your gasoline powered trimmer.

An important part of the maintenance procedure for

all

two-cycle engines is the cleaning or decarboning

of

the

unobstructed flow of exhaust gases and particles

from the combustion chamber. A severely carboned

muffler, spark arrester screen. and/or exhaust port

will

cause poor starting and low power output of the

trimm'er engine.

1.

Remove the muffler shield, screen, muffler and

exhaust gasket.

2.

Soak the screen

build-up

3.

Clean the muffler baffle holes inside the muffler

with a screwdriver.

4.

Check the cylinder exhaust port. If necessary,

remove the carbon deposits from the port using a

SYSTEM

exhaust system. This is done to assure the

with

wiiden

stick (Fig.

MAINTENANCE

in

solvent and remove the carbon

a wire brush, or replace the screen.

8).

in

3.

Wash the foam filter and dry thoroughly. If the filter shows any sign of damage or deterioration, replace

4.

Saturate the foam filter SAE

30

oil. Squeeze the filter to distribute the oil

evenly and to remove excess oil. A damp element

is necessary to ensure proper functioning of the

air cleaner.

4

in

a soap and water solution

it.

with

one teaspoon (5ml)

Figure

8

IMPORTANT: WHEN REMOVING CARBON DEPOSITS, CLOSE THE PORT WITH THE PISTON

TO PREVENT LOOSE CARBON DEPOSITS FROM

FALLING INTO THE CYLINDER. TAKE CARE NOT

TO SCRATCH THE PISTON. DO NOT USE A

METAL TOOL SUCH AS A SCREWDRIVER.

5. Reassemble

exhaust gasket.

the muffler components. Use a fresh

FLEXIBLE DRIVE SHAFT MAINTENANCE

The flexible drive shaft has been lubricated at the factory. After approximately tion, the shaft should be removed from its housing and its entire surface coated ,purpose, lithium-base grease. To remove the shaft,

loosen the lower handle and slide engine assembly to expose the clamp. Loosen the clamp and separate the upper and lower tube assemblies. The shaft from the lower tube (Fig.

will

every 40 hours

with

a

then be able to be pulled

of opera-

No.2

it

toward the

general

9).

Figure 10

CAUTION:

RUNNING CARBURETOR CAN BE PERFORMED. TO GUARD AGAINST POSSIBLE PERSONAL INJURY, KEEP HANDS, FEET AND

FACE AWAY FROM MOVING PARTS.

2. Start

mately 3-5 minutes.

when the engine is cold. Be sure to perform the carburetor adjustments while

wh

SO

the engine and let

to the average outdoor temperature at the trimmer

THE ENGINE MUST BE

FINAL ADJUSTMENTS OF THE

it

warm up for approxi-

Do not adjust the carburetor

in

an area that is

will

be used.

Figure 9

CARBURETOR ADJUSTMENTS MODEL TC-1500 WITH TILLOTSON CARBURETOR

The carburetor has been adjusted at the factory, but an adjustment may be required to compensate for differences Tillotson carburetor used on the TC-1500 is not

serviceable. If carburetion difficulties cannot be

corrected by adjustment, the carburetor must be

replaced. IMPORTANT: The correct amount of line must be fed

from the trimmer spool before adjusting the car-

buretor to ensure that the engine is adjusted for

operation while under load..

1. Remove

bottom of cover

and pressing

tab. DO NOT FORCE (Fig. 10).

in

fuel, temperature and altitude. The

air cleaner cover by pressing up

to

release lower mounting tab

in

on front of cover to release upper

on

CAUTION;

ORS WITHOUT ADEQUATE VENTILA-

EXHAUST

AN

I

COULD BE DEADLY NO poi

Hig

If the engine

setting is lost, set both screws

to

"5%".

number settings are rich. (Fig. 11).

DO NOT RUN THE TRIMMER

FUMES

will

Low number settings are lean.

Figure 11

ARE

IF

INHALED.

not start or if the refer-

POISONOUS

so

the arrows

5

MAINTENANCE

3.

Adjust Idle First: With engine idling, rotate the Low Speed Screw (L) for the leanest fuel mixture that allows stable idle, and acceleration without hesitation.

4.

If

necessary, idle speed can be increased by

turning the idle stop screw clockwise (Fig.

12).

PROCEDURES

2.

Low

Speed Screw by gently rotating resistance is felt. Next, rotate the screw turns counterclockwise.

3.

Idle Screw (Fig.

it

clockwise until the screw contacts the throttle lever After contact is made, continue turning screw

11/2-21/2

(L)

(Fig.

13)

it

clockwise until a light seating

13)

Close

additional turns.

Close the screw

the screw by rotating

1 1/4-1 1/2

Figure

5.

Hold the throttle trigger at the maximum speed position and adjust the High Speed Screw (H) for maximum engine speed.

6.

Recheck the idle adjustment.

CARBURETOR ADJUSTMENT MODELS TC-

300,

TC-400 WITH WALBRO CARBURETOR

IMPORTANT: Do not close the carburetor adjusting screws too tightly as damage to the screws and seats

may result. Also, the correct amount of line must be fed from the trimmer spool before adjusting the carburetor to ensure that the engine is adjusted for operation while under load.

1.

High Speed Screw (H) (Fig.

by gently rotating

resistance is felt. Next, rotate the screw one turn

counterclockwise.

it

12

13)

Close the screw

clockwise until a light seating

Figure

NOTE: Although these settings are approximate, the should be able to be started. Further adjustments of the carburetor may be necessary to obtain the best performance for your area. Steps

carburetor.

turn the screws the 'engine to respond to the change.

4-6

should be followed to fine tune the

When making these adjustments,

1/8

of a turn at a time and wait for

13

6

MAINTENANCE PROCEDURES

4. Start

the

engine and

mately

when the engine is cold. The adjustments should

be made

will

sary, re-adjust the idle speed to keep the engine from stalling 3000-4500 on the TC300)

3-5

minutes. Do not adjust the carburetor

at

the temperatures

be used. Allow the engine to idle. If neces-

(3000-3500

CAUTION:

INDOORS WITHOUT ADEQUATE VENTILA-

TION. EXHAUST FUMES ARE POISONOUS AND COULD BE DEADLY

let

it

warm up for approxi-

that

the trimmer

RPM on the TC400,

DO NOT RUN THE TRIMMER

IF

INHALED.

TROUBLESHOOTING AND

TEST PROCEDURES

Generally, all gasoline-powered products require some form of service or repair during their lifetime. The amount of time and expense involved ing a product can be greatly impacted by the amount of time required to initially determine the cause of the difficulty. Therefore, these preliminary checks before proceeding to secondary troubleshooting procedures.

Preliminary Checks

1. Check for ignition: a. Check the start/stop switch position

it

is recommended to make

in

repair-

5.

With' the engine idling, slowly turn the low speed

screw

the engine begins to slow down. Now turn screw counterclockwise and again note the position when the engine speed is reduced. Set the screw at a point midway between these two positions.

6.

Hold

procedure to set the high speed screw.

7.

Re-check the idle adjustment.

8.

Install

parts within the engine. This test cylinder, piston, or ring and generally determine

whether

replaced,.

Compression

1.

Install the compression gauge into hole. :IMPORTANT: Be certain that no more than

1/2”

damage to the piston may result (Fig. 14).

clockwise and note the position

the

throttle wide open and follow the same

the

air cleaner cover.

will

the engine is sound or if

Test

Procedure

of

the gauge is threaded into the cylinder as

at

indicate a worn

it

should be

the

spark plug

which

the

a

2.

Check the spark plug: (refer to specifications.

Page

3)

a.

To ensure b. For damage to the insulator c. For excessive carbon or burnt electrodes d. For the correct gap

e.

Check for spark (refer to page

3. Check a. Check the choke position

4. Check the air cleaner: (refer to page

5.

Check cylinder compression (refer to page

Testing

A compression test of the engine can provide vital

information on the general condition of the working

the

b. Check the condition of the fuel, for freshness,

cleanliness, and proper mixture

a. For loose or damaged mounting screws b. For dirty filter elements c. For excessive oil

Cylinder Compression

the

correct type

fuel supply:

in

8)

4)

the foam element

7)

Figure 14

Compression testing

2.

Pull

the

starter rope several times to obtain the

highest possible compression reading.

3. If the compression reading is below kPa),

cylinder,

suspected If block /should be installed.

piston, or ring damage should be

so

damaged, a

new

100

psi

engine

(689

short-

7

TROUBLESHOOTING AND

TEST PROCEDURES

Checking for Spark

1. Pull off the spark plug cap and remove Plug.

2.

Inspect the spark plug for wear, carbon deposits and damage. Replace or fouled.

3.

Check for the correct spark plug gap and adjust if necessary to outer electrode.

NOTE:

could crack the insulator.

4.

Attach a spark or ignition tester as shown

Figures 15 or

5.

While maintaining the plug the starter-rope and observe for spark.

.020-.024

Do

not pry against inner electrode. This

16.

CAUTION:

ERE

GASOLINE HAS BEEN SPILLED

MABLE VAPORS MAY EXIST. A

NOTE: The spark may be difficult to see

or other brightly illuminated areas.

6.

If no spark is seen, refer to the troubleshooting chart on page

9.

the

plug if damaged, burnt

in

(5.6

DO

NOT TEST FOR SPARK

mm) by bending

in

this position, pull

the

FIRE

in

daylight

spark

OR

in

Checking Fuel Tank Venting

The fuel tank cap vent allows air into the tank as fuel is consumed. If this vent is blocked the engine will eventually stall.

1. Remove the fuel tank cap and inspect the vent. If the

cap is contaminated with dirt particles, the

vent may need to be replaced.

2.

The cap can be disassembled by prying up the insert with a flat screwdriver. Care should be used to prevent damage to valve (Fig- 17).

Figure 17

3.

Remove the valve, squeeze the valve to close release be visible through the valve. If light can be seen, the~valve should be cleaned or replaced.

4.

With the insert removed, hold the cap up to light. Light should be visible through a small hole at the'

it,

and hold

the center of the cap. if

hole

should be cleaned.

it

up to a light. No light should

with

dust or dirt,

the

insert and the

no

light can be seen,

it,

Checking fuel tank

a

Figure 15

Spark

Toro P/N 41-7890

Alternate type spark tester

tester

Figure

16

1.

Visually inspect the bottom of or other contaminants.

2.

If dirt, water, or other contaminants are present,

the

;tank should be flushed with a small amount of

fuel, and refilled with fresh fuel.

I

the

fuel tank for dirt

Checking the Stop Switch

The “off” switch used on the

400

Gas

Trimmers has one set of contact points. When the switch is in the "off" position, the contacts are closed, grounding the coil current to the engine.

A continuity tester or ohmmeter is used to check for continuity Note: If should, be adjusted to a low setting. Attach the two tester (leads to the two switch leads. Continuity should be evident with the switch in the "off" position. continuity If continuity is intermittent or not evident, the switch is defective or a short has developed in

the

replaced.

In

the "on" position there should be no

wiring and the switch and harness should be

an

ohmmeter is used .the dial

Toro

1500.

300,

and

TROUBLESHOOTING SHOOTING

AND TEST PROCEDURES

DISASSEMBLY,

REPAIR,

REASSEMBLY

Trimmer Engine Removal, Disassembly,

Replacement

1.

Drain the gas from the trimmer gas tank and remove the spark plug high tension wire.

2.

Remove the air cleaner cover by pressing up on

the bottom of the cover to release the lower

mounting tab, and pressing cover to release the upper tab.

3.

With the trimmer on its left side, remove the nine Phillips head screws which attach the case

halves together. NOTE: A service fixture, plans

for which are described

Service Bulletin No.81-05, is very useful for

supporting the trimmer for disassembly and

reassembly.

4.

Remove the right hand case half by lifting

the left hand case half. The case half may

appear to be stuck to the engine due to the fit of the rubber engine isolation mounts between the case and the engine backing plate. NOTE: When

reassembling, install the rubber isolation

mounts

engine backing plate.

5.

Remove the engine housing tube and recoil

starter assembly by tipping the engine to the

rear and lifting the tube and starter from the left

hand case half.

6.

IMPORTANT: Note how the fuel line, throttle

lever, throttle link, spring, switch, and wiring

harness are routed and attached (Fig.

Mounting

Engine

in

the case halves rather than on the

Block

in

on the front of the

in

Gasoline Trimmer

it

18).

from

INSTRUCTIONS

8.

Remove the throttle and switch, assemblies and Iift, the engine from the Left Hand Case.

I

9. Remove

clip.

10, Remove the carburetor by removing the Phillips

head screws which pass through the spit back/ choke assembly and carburetor.

11.

Remove the cooling shroud halves by removing

the three screws which attach the shroud to the

backing plate, and gently prying open the latch

next to the spark plug wire. NOTE: The TC300

and TC400 have a single piece cooling shroud.

12. Remove the flywheel by retaining the starter cup

and removing the flywheel

Use

separate the flywheel from the crankshaft taper. The two holes cast into the flywheel should be tapped

long capscrews used to apply pressure against

the: crankshaft end

flywheel and crankshaft

CAPTION: DO NOT attempt to pry the flywheel from the crankshaft or tap on the crankshaft end to loosen the flywheel. The crankshaft is made

up of three parts, pressed onto the crankpin. Prying or striking the crankshaft can result replacement of the short block.

13. Remove the CDI (Ignition) Module by removing the' two screws which attach the laminations to the' cylinder assembly.

14.

Remove the backing plate assembly by removing the three bolts and two Phillips head screws which pass through the backing plate and back-

ing'plate stress plate into the cylinder assembly.

the air cleaner elements and retaining

with

the starter cup wrench P/N45-1390)

nut

(Fig. 24, p. 17).

the handle of the starter cup wrench to

with

a

l/4"-20

tap, and two 1/4”-20 x 3/4”

until

the seat between the

is

loosened.

with

the crankshaft ends being

in

damage that

will

require

Figure 18

7.

Remove the gas line from the carburetor inlet by compressing and sliding the fuel line clamp up onto the fuel line and twisting and pulling fuel line.

10

on

the

NOTE (TC1500 only): The intake gasket is sealed

with

a light coating of gasket sealant, and the backing plate may appear to be stuck to the cylinder assembly.

15. Remove the crankcase pad by squeezing the end of the crankcase pad clip through the hole

16. Remove the heat shield and muffler by removing the' two hex socket capscrews and the Phillips

head screw to the heat shield tab. The

then be removed by removing the Phillips head

w

that fastens

in

so

that

it

can be passed

the crankcase.

tab

it

to the cylinder assembly.

can

Figure

19

REASSEMBLY

DISASSEMBLY, REPAIR,

INSTRUCTIONS

Starter Rope Replacement

1.

Follow steps 1-5 of Trimmer & Engine Disas-

sembly/Assembly Instructions. NOTE: Do not

remove the Recoil Starter Assembly from the Upper Shaft Housing Tube.

2.

Remove the damaged rope from the pulley.

3. Knot one end of the replacement rope. Align cut-out sections of the Drum and the metal Ratchet Cover. Feed the un-knotted end of the rope through the clearance hole and into the rope groove

in

the Drum (Figure

20).

the

end of the rope remaining through the guide slot bushing and handle.

5.

IMPORTANT: Check the starter for proper assembly

by

extending the starter rope full length. With the rope extended, to be rotated an additional direction but not more

6.

To reassemble reverse steps

Instructions (page

Starter Assembly Replacement.

1.

Follow steps

2.

Remove the Recoil Starter Assembly from the Upper Shaft Housing Tube. Retain passing a bar through the holes

the Recoil Starter Assembly to remove.

in

the retainer. Install

the

starter pulley must be able

than

IO).

1-5

of

Trimmer & Engine Disas-

Instructions.

the

1/2

turn in a clockwise

1 1/2

turns.

1-5

in Disassembly

the

tube by

in

the tube. Twist

rope

Figure

4.

a.

TC 1500, TC300, TC400 Wind the rope clockwise onto the drum, slipp-

ing the rope under the four retainer tabs (do not wind the drum) until the handle is within

inches from the Drum. Continue by rotating the Drum and sliding the rope under the retainer tabs until the rope extends through the widest gap between the rope retainer tabs.

Install the rope bushing and handle.

b. TC400 (step 4a or 4b

upon the style of the starter drum)

Wind

the

rope clockwise onto the drum, slip-

ping

the

rope between the retainer and the

drum until 2 inches of rope remains. Thread

20

will

apply depending

2

3. Press the Recoil Starter Assembly which are retained

4. IMPORTANT: Check the starter for proper as-

5.

the

replacement Recoil Starter Assembly

into: the Upper Shaft Housing Tube. The slots by the Trimmer case halves must be in line with

the locating holes in between rope retainer tabs on the Starter must be rotated the tube. NOTE: Press only on the end of the

Recoil Starter Assembly.

sembly by extending the starter rope full length. With the rope extended, the starter pulley must be able to be rotated and clockwise direction. If the Starter Drum stops

rotating before the rope is extended full length,

remove one wrap of the Starter Rope by sliding from under the rope retainer tabs and repeat test

procedure. If more than wrap one more turn on the starter.

To reassemble reverse steps

Instructions)page

180°

the

tube, and the widest gap

from the Pole Clamp slot cut

additional 1/2 turn

1 1/2

turns are possible,

1-5

in

Disassembly

10).

in

a

it

DISASSEMBLY, REPAIR,

REASSEMBLY INSTRUCTIONS

WALBRO CARBURETOR OPERATION

1.

Engine Impulse: Actuates Fuel Pump Diaphragm with alternating pressure-vacuum pulses.

2.

Fuel Pump Diaphragm: Fluctuates impulse. Transfers fuel through Fuel Pump Valves.

3.

Fuel Inlet: Fuel drawn from tank.

4.

Inlet Valve: Responds to Fuel Pump Diaphgram. Opens during vacuum pulse. Closes during pressure pulse.

5.

Outlet Valve: Closes during vacuum pulse. Opens during pressure pulse.

6.

Filter Screen: Filters fuel on route to Metering Chamber.

7.

Inlet Needle Valve: Lifts off seat to allow fuel entry into

Metering Chamber.

8.

Throttle Valve: Regulates engine speed

mary. Second, and Third Idle holes, then Nozzle for fuel

delivery.

9.

Primary Idle Hole: Only fuel source to engine at Idle position.

10.

Second Idle Hole: Allows additional fuel flow on acceleration.

11.

Third Idle Hole: Increases fuel flow at Part Throttle.

12.

Idle Needle: Adjust for fuel richness to 3 Idle holes.

in

response to engine

as

it

exposes Pri-

Alternate fuel pump system modate internal pulse and/or external fuel source.

13.

Idle take-Off: Fuel entry for Idle holes.

14.

Idle Port: Fuel reservoir for Idle holes.

15.

Atmospheric Vent: Allows air pressure against Metering Diaphragm.

16.

Circuit Plate: Meters fuel from Metering Chamber to Low Speed and High Speed Circuits.

17.

Metering Diaphragm: Drawn up by vacuum to activate Metering Lever.

18.

Metering Lever: Lifts Inlet Needle

19.

Metering Lever Spring: Transmits force to Metering Lever.

Closes

Needle Valve as Metering Chamber fills.

20.

Metering Chamber: Fuel reservoir, feeds to Idle and Nozzle

off

seat.

to

accom-

circuits.

21.

Nozzle Check Valve: Engine vacuum draws Valve open.

22,

Nozzle Well: Fuel is drawn high speed

23.

Hi Speed Needle: Adjusts for fuel richness at high speeds.

24.

Nozzle Increases fuel discharge for high speeds.

25.

Venturi: Increases air velocity at Nozzle, creating a suction to draw fuel into Throttle Bore.

in

from Metering Chamber at

13

DISASSEMBLY, REPAIR,

Metering Lever

Inlet Needle

Fuel Inlet Screen

Fuel Pump Diaphragm

REASSEMBLY

WALBRO CARBURETOR

V

INSTRUCTIONS

SERVICING

-Metering Diaphragm Cover

-Metering Diaphragm Assembly

Metering Diaphragm Gasket

Circuit Plate Assembly Circuit Check Valve

Circuit Plate Gasket

Throttle Valve Screw

Throttle Valve

,Idle Needle

Hi Speed Needle

Throttle Shaft Assembly

Fuel Pump Gasket

Idle

Fuel Pump Cover

Figure

Carburetor Disassembly (Refer

1. Remove the fuel pump cover screw and pump cover.

2.

Remove the fuel pump diaphragm and fuel pump and foreign matter. gasket.

3.

Inspect the diaphragm for flatness and continu- lever components including lever, pin, needle ity. The diaphragm should have flapper valves should be flat and free ,from curling.

4.

Blow through the external pulse hole on the body casting to insure that there are no structions.

5.

Blow through the internal fuel hole on the body casting to insure that there are no obstructions.

6.

Remove and discard the filter screen.

7.

Remove the four screws and metering dia- operation of the throttle valve and lever.

phragm plate.

to

Fig.

22):

no

holes. The valve and spring.

ob-

22

8.

Remove the metering diaphragm and gasket.

9.

Inspect the metering diaphragm for holes, dirt

10. Remove the metering lever screw and metering

11. Remove the circuit plate screw with the diaphragm and gasket.

12. Remove the high and low speed adjustment

needle

13. Thoroughly inspect and clean the carburetor, especially all small orifices and openings, using a solvent wash and an air gun.

!

14. Dry the carburetor with air and inspect the

Adjust Screw

14

DISASSEMBLY,

REPAIR,

REASSEMBLY

Carburetor Re-Assembly

1.

Install a new filter screen

hollow tube or tool of approximately diameter. NOTE: The screen must be pushed far enough to be below the fuel inlet hole.

2.

Inspect the circuit plate for flatness and correct if

necessary.

3.

Inspect the new circuit plate diaphragm and gasket for flatness. Install the circuit plate, circuit

diaphragm and circuit plate gasket with

phragm in contact with the plate contact with body casting.

pressure on the circuit plate screw

warp the circuit plate.

4.

Install the metering lever components and adjust

the metering lever to be flush the circuit plate, Fig.

23.

with

any appropriate

,300

and

gasket in

Use only moderate

so

as not to

with

the surface of

INSTRU'CTIONS

5.

Install the high and low speed needles and set at

inch

in

dia-

approximately 1 and low speed letters are indicated on the side of the carburetor casting. The high speed needle is the long needle and the low speed needle is the short needle.

6.

Install the metering diaphragm and related components as follows: Install the gasket over the locator pins on the casting. Next, install the

metering diaphragm over the locator pins on the casting. (The metering plate pin must be tact

with

metering diaphragm cover vent hole the throttle valve.

7.

With

cover

with the body casting

gasket in contact with the fuel pump cover.

extension on the cover should be located on the same side as the throttle lever.

in

the large single screw, install the fuel pump

with

1/4

turns open. The high and

in

con-

the metering lever.) Next, install the

with

four screws. The

the cover should be located opposite

the

fuel pump diaphragm in contact

and

with

the

fuel pump

The

Figure

23

8.

Visually inspect the carburetor and tighten all

screws.

15

of

Difficulty

TROUBLESHOOTING AND

TEST PROCEDURES

CUTTER HEAD TROUBLESHOOTING

Reduced cutting ability

Cutting line fails

to

advance

Cutting line pulls back into drum tangles)

spool

Line

to turn

Clutch fails to

engage

Clutch fails disengage at idle speed

fails

to

(or

RPM

too

low

too high

Binding

Not seated engine cutting unit

Not seated in engine cutting unit

in

or

I

Bearing seized

Cutting line Clutch slipping too short, won't index

Driver broken,' line swelled from moisture, dirty, line

tangled Cutting line not

indexed often enough to engine shut

Off

Driver

broken

Unbalanced cutting unit, bearings worn,

dirt

accumulation

or

I

prior

drum

Bearing grease on clutch drum

Power

shaft snap ring out groove (some models), clutch spring broken

Incorrect assembly

of

I

16

i

DISASSEMBLY,

REASSEMBLY

CLUTCH

INSTRUCTIONS

REPAIR

REPAIR,

The clutch consists of two assemblies: (Fig. 24):

A. The upper housing containing the upper power

shaft, ball bearing, oil shield, clutch spacer, clutch assembly and

B.

The lower bearing housing and clutch drum which is threaded to the lower housing shaft.

NOTE: The oil shield was not used production of the TC-400 clutch assembly. Also,

the upper power shaft

changed to a machined shaft The two shafts are interchangeable. The oil shield may be added to existing clutch assemblies using the upper shaft

ring.

Disassembly

1.

Remove the cutter head

2.

Remove the clutch housing from the trimmer

tube by loosening the housing clamp bolt.

3.

Remove the six screws securing the upper and lower sections of the clutch housing. Separate the two sections by gently prying them apart.

4.

The clutch assembly (shoes and springs) can be

removed

1390

holes

the opposite end of the power shaft

&

Assembly

with

the multipurpose tool P/N #45-

(Fig 25). Align the pins on the tool

in

the clutch assembly. While supporting

with

the snap ring was

with

instructions

or

line feed assembly.

in

early

a shoulder.

the machined

with

the

with

a piece

of

3/16

inch square key stock, turn the clutch assembly counterclockwise. The spacer, oil shield and power shaft can now be removed.

Clutch

Wrench

Multipurpose tool (P/N 45-1

NOTE; When reassembling the clutch shoe and spring assembly, be sure "off" is toward you. The wide flange on the spacer must be against the clutch shoe and spring assembly.

5.

Remove the three screws The bearing fits loosely and can be pushed out by

gently tapping the bearing from the top or clamp

end

of

the housing.

6.

The shaft and bearings

ing are not serviceable as individual components and must be replaced as an assembly.

Figure 25

that

in

the lower clutch hous-

390)

the side marked

the bearing retainer.

17

DISASSEMBLY, REPAIR,

REASSEMBLY

AUTOMATIC

1.

Drain the gasoline from the fuel tank and remove

the high tension wire from the spark plug.

2. Insert a medium flat screw driver in one of the two window slots in the spool will snap off. (Fig. 26). NOTE: Use as wide screw driver as damage the cap.

will

spool

fit

in

the slot

Figure 26

hub and twist. The

so

as not to

INSTRUCTIONS

LINE

a

FEED

3.

Hold

core counterclockwise. The driver

with

4.

Remove the washer and compression spring and slide the drum off the power shaft.

5.

Clean the debris from the inside and outside of the the, power shaft.

6. Replace any worn or broken parts.

7.

Reassemble the trimmer head in the reverse

order. Be certain that the roll pin on the power

shaft is seated

8.

The spool and spool core are keyed. They must be

properly aligned when putting the spool back on.

Thread the end of the line through the eyelet.

Plate the spool on the keyed core and push in

place until you hear

REPAIR

the drum securely, and unscrew the spool

it.

drum

and remove any debris wrapped around

in

the slot in the drum.

it

click.

will

turn off

18

Toro 51603, 51604, 51630 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

ENGINE TORQUE SPECIFICATIONS

AIR CLEANER MAINTENANCE

FLEXIBLE DRIVE SHAFT MAINTENANCE

Checking for Spark

Checking Fuel Tank Venting

Checking fuel tank

Checking the Stop Switch

Starter Rope Replacement

WALBRO CARBURETOR OPERATION