Mtd FARMALL CUB user Manual

FICA TIONS

General

Model C-60
Numberofcylinders 4

Bore and stroke -inches. 2-5/8 x 2-3/4Displacement-cubic

inches 59.5

Engine rpm (governed) Eng. Sere No. U312389 Eng. Sere No. U312390

and below and above

Low idle.:t. 25 475 475

Highidle.:t.25 2000 2080
Ratedload.:t.l0 1800 1900

Compression ratio. 6.5-1

Compression pressure at cranking speed -psi. 120

Firing order. 1-3-4-2

Ignition timing

High idle 16oBTDC
.375rpmorbelow mc

Distributor point gap -inch. 020

Sparkpluggap-inch 023

Cylinder bore -inches. 2.625 -2.627
Camshaft bearing bore diameters

Front -inches. Center-inches Rear-inch

1.8740 -1.8755

1.7490 -1.7505
.8740 -.8755

Crankshaft and Main Bearings
Crankshaft

Type Counterbalanced

Number of main journals. 3
Main journal diameter -inches. 1.623 -1.624
Crankpin diameter -inches. 1.498 -1.499

Main Bearings
Type Tri-metal,precision

Running clearance -inch. 002 -.003

Thrust bearing location. Center
Thrust bearing side clearance -inch. 004 -.008

GSS-1411 (Rev. No.1)

SPECI

Crankcase

Printed in United States of America

1-4

Bearing aD and spread

Front and rear -inches. 1.777 + .020

Center -inches. 1.777 + .002 to .015

Camshaft
Drive. Helical gear

CaIn lobe lift (total) -inch. 232 :t. .002

Diameter at bearing areas

Front-inches Center-inches Rear-inch

1.871- 1.8721.746

-1.747

.872 -.873

Thrust taken by Thrust plate
Number of bearings. 3 (bored in crankcase)

Bearing running clearance

Front and center -inch. Rear-inch

End clearance -inch.

.002 -.0045
.001 -.0035

.003 -.012

Connecting Rods
Type I-Beam

Side clearance -inch. 005 -.012
Bearing running clearance -inch. 002 -.003

Bearing type

Upper end. Bronze bushing
Lower end. Tri-metal, precision

Bearing OD and spread -inches. 1.625 + .025

Piston pin bushing (installed and bored) ill -inch. 6879 -.6882

Pistons

Type Full skirt

Material Grey iron
Overall length -inches. 2.875
Diameter -inches. 2.6230 -2.6234

* Skirt clearance, bottom -inch. 0016 -.0024

(measured at 900 from pin hole)

Number of rings per piston. 3

Piston pin hole bore -inch. 6877 -.6880

*See "Piston Fit in Bore", page 1-31.

1-5

Pistons -Continued

Width of ring groove -inch

Topcompression Second compression. Oilcontrol

Ring clearance in groove -inch

Topcompression .

Second compression. Oilcontrol

Piston Pins

Type Diameter -inch. Length -inches. Clearance between end of pin and retainer ring -inch. Clearance in rod bushing -inch. Clearance in piston -inch.

Piston Rings

.0955 -.0965

.0955 -.0965.1880

-.1890

.0020 -.0035
.0020 -.0040
.0015 -.0030

Full floating

.6875 -.6876

2.185 -2.195
.010 -.030

.0003 -.0007

.0001- .0005

Compression

Number per piston. Type

Second..

Chrome

2

Plain

Width of ring

Top -inch. Second -inch.

.0930 -.0935

.0925 -.0935

gap

Top -inch. Second -inch.

.007 -.017

.007 -.017

Oil Control

Type Chrome, wide slotNumber

per piston. 1
Width -inch. 1860 -.1865
End gap -inch. 007 -.020

Top.

End

1-6

Valves

Head diameter

Intake-inches 1.089-1.099

Exhaust-inch 901-.911

Face angle-degrees 45-1/2
Stem diameter

Intake-inch Exhaust-inch

-.3105.3095

-.3105

in guide

Intake-inch Exhaust-inch

Valve Seats

Seat angle -degrees. 45
Seat width

Intake-inch Exhaust-inch

Valve Guides

Length -inches. Inside diameter

Intake-inch Exhaust -inch.

.001 -.003

.0015 -.0035

3/64
3/64

1.34

.3115 -.3125.3120

-.3130

height below crankcase surface -inches.

Valve Springs

length

Intake-inches Exhaust w /0 rotocap -inches. Exhaust w/rotocap -inches.

Test length

Intake -inches. 1-1/4

Exhaust w /0 rotocap -inches. 1-1/4
Exhaust w/rotocap -inches. 1-3/16

.3095

Clearance

Installed

1-3/32

Free

1-31/321-31/32

1-7

1-7/16

Valve Springs -Continued

Test load

Intake -pounds. 23

Exhaust w /0 rotocap -pounds. 23
Exhaust w/rotocap -pounds. 14 -16

Valve Tappets

Diameter -inch. 591- .592

Length -inches. 2.370 -2.380

Clearance in crankcase -inch. 0007 -.0032

Valve lash (engine cold) -inch. 015

Valve Timing
Intake opens -degrees. 10 before TDC

Intake closes -degrees. 45 after BDC

Exhaust opens -degrees. 45 before BDC
Exhaust closes -degrees. 5 after TDC

Cylinder Head

Boltdiameter-inch 3/8

Torque-ft.lbs. 45

Gears

Crankshaft pinion. 18 teeth
Camshalft gear. 36 teeth
Idler gear. 36 teeth

GovernQr-ignition gear. 18 teeth
Type of teeth. Helical

Backlasb -inch. 003 -.006
Idler shiaft retainer bolt tension -ft. lbs. 90

LubriC$tion System

Oil pressure at 1800 rpm -psi. 30 -35

Oil pump .

Type Gear

Drive. Direct from camshaft

Gear b;acklash -inch. 003 -.006

Timing

1-8

Numb~r of teeth

Idler gear. 13

Drilvegear 13

lubrication System -Continued

Oil pressure valve regulating spring

Free length -inches. 2-31/32
Test length -inches. 2-15/32

Testload-pounds 9-1/2

regulating valve

Valve diameter -inch. Location

.6205 -.6215

In crankcase

Special Torques (foot pounds)
Cylinder head 45

Main bearing. 55
Connecting rod 16

Flywheel. 45
Idler gear retainer bolt. 90

Manifold 20

Spark plugs 30

Pressure

1-9

REMOVAL

1. Disconnect the ground cable from the ~

battery, and the wires from the headlights.

2. Remove the headlights. Shut off
fuel at the fuel strainer and disconnect
the fuel line. Remove the hood and fuel
tank assembly.

3. Block the front axle on both sides

with wooden wedges (2). Support the
rear of the tractor with the support

standst FES 142-1.

4. Remove the pipe plug located in
the bottom of the steering gear housing

assembly (6) and drain the coolant.

5. Disconnect and reDlove the vvater

inlet (3) and outlet elbovvs (4).

6. Remove the water inlet nipple

from the R. H. side of the steering gear

housing.

'? Remove the screws securing the

cooling fan housing (5) to the radiator.

8. Disconnect the steering shaft

bracket (2) from the steering support
arm (3).

~: The front axle and radiator

assembly must be supported by a stand
or jack to prevent it from tippingbackward.

9. Remove the two bolts and two cap

screws between the engine and steering
gear housing.

ENGINE

1-10

10. Raise the engine so the fan drive
pulley (1) clears the steering gear hous­ing (2) and roll the front axle away from

the engine.

11. Attach the lifting brackets (3)

FES 100, to the engine and support it
with a sling (4), FES 138, and a hoist.

12. Perform a front section split to

remove the engine from the clutch hous-

ing (2). (Refer to "Front Section split",

Section 4.)

1-11

ENGINE INSTALLATION

1. If the clutch assembly was re­moved from the engine, use a pilot shaft
to center the clutch driven disc. (Refer

to clutch "Installation", Section 5.)

2. Support the engine using the lifting

brackets, lifting sling and a hoist, and

position the engine on the clutch housing.

3. Install the two cap screws and the

nuts and bolts in the engine and clutch

housing. Tighten to 55 and 35 ft. lbs.
torque respectively.

4. Install the clutch housing cover and

secure with the nuts and bolts. Install

the clutch housing hand hole cover if it

was removed.

5. Connect the wiring harness wires

to the coil, ground, regulator and lights.

Connect the wire to the starter.

6. Using a new gasket and O-rings,

install the hydraulic manifold tubes to the

pUInp and the cylinder block assembly.

7. Install the governor control rod.

8. Install the choke control rod.

9. Install the exhaust pipe.

10. Position the steering gear housing

assembly (2) on the front of the engine.

11. Install the cooling fan housing on

the radiator.

12. Install the cap screws and bolts

securing the steering gear housing to

the engine.

13. Connect the steering shaft bracket

to the steering shaft support arm.

1-12

14. Install the water inlet nipple in the

steering gear housing.

recommended coolant. (Refer to
Operator's Manual.)

15. Install and connect the water inlet

and outlet elbows and hoses.

16. Install the pipe plug in the steering

gear housing and fill the radiator with the

Removal

1. Remove the pipe plug in the bottom

of the steering gear housing and drain

the coolant.

2. Disconnect and remove the head-

lights.

17. Install the hood and fuel tank as-

sembly. Connect the fuel line to the fuelstrainer.

18. Connect the wires to the lights and

the ground wire to the battery.

HEAD

4. Remove the water outlet elbow

and hose.

Remove the spark plugs.

3. Disconnect the fuel line from the
fuel strainer. Remove the hood and fuel
tank from the tractor.

6. Remove the cylinder head capscrews,
and remove the cylinder head

and gasket from the engine.

1. Check the head and gasket for

"blow-by" or compression leaks.

2. Remove carbon from combustion

chamber cavities with a wire brush.

3. Clean cylinder head combustion

cavities with cleaning solution.

Carefully inspect head for cracks.

CYLINDER

5.

4.

1-13

Installation

5. Use a straight edge and inspect for

warped head, particularly in any area
which shows "blow-by. II

6. Inspect water jacket in head for an

acc~ation of rust or lime depositwhich

would affect circulation of cooling

water and cause hot spots. Clean ifnecessary.

7. Thoroughly clean the gasket surfaceto

insure proper sealing of the new gasket.

Be sure to use a ~ gasket.

1. Using a new gasket, install the cyl-

inder head on the engine.

2. Install the cylinder head cap screws.

Using the sequence shown, tighten evenly

in steps to 45 ft. lbs. torque. Be sure to
install all brackets and mounting clips
under the cap screw heads before tighten-

9

8

12

FESM-3249

ing.

3. Install the spark plugs and tighten

to 30 ft. lbs. torque.

4. Install the water outlet elbow andhose.

5. Install the hood and fuel tank and

connect the fuel line.

6. Install the headlights and connectthe
wires.

8.

7.

1-14

Refill the radiator with coolant.

Valve lash Adjusting Procedure

Following the simplified procedure in the

chart below, all valves can be adjusted

accurately. Note that the engine does notneed

to be cranked four times to positionthe

piston of each cylinder on T .D.C. All

valves are adjusted by cranking the engine

only twice.

Four valves are adjusted when the No.1

piston is at T .D.C. (compression) and the

remaining four are adjusted when the

No.4 piston is at T .D.C. (compression).

1. Remove the intake and exhaust

manifold assembly. Remove the valve

tappet cover. Clean the gasket mating
areas to insure proper sealing when re-assembled.

2. Check the entire valve assembly

for rust and dirt. Inspect for looseness
in the valve assembly and for worn or
broken valve springs.

3. Remove the spark plugs from No.1

cylinder (nearest the radiator) and No.4
cylinder.

4. Place a thumb over the No.1 spark
plug opening and slowly hand crank the
engine until an outward pressure can be
felt. Pressure indicates the piston is
moving toward top dead center of the

compression stroke.

5. Continue cranking slowly until the

T .D.C. mark (1) on the fan drive pulley
(3) is in line with the timing pointer (4)

on the crankcase front cover.

~ : Valve tappets have self-locking
tappet screws. Adjustment requires two
wrenches, one to hold the tappet and one

to turn the tappet screw.

VALVES

1-15

6. Insert the feeler gauge between the
valve tappet and the valve stem. The
specified clearance is .015 inch (engine
cold). Turn the adjusting screw in or out
as necessary to give a slight drag on the

feeler gauge. Adjust the four valves

specified in the chart on page 1-15.

7. Crank the engine until the No.4

piston is on T .D.C. (compression) and the

T .D.C. mark (1) on the fan drive pulley is
in line with the timing pointer (4). (Refer

to illustration on page 1-15.) Adjust the
remaining four valves.

8. Install the valve cover being sure

to use a new gasket. Check for any oilleaks.

9. Install the intake manifold with a

new gasket.

Removing Valves

~: When valve assemblies are re-

moved, all parts should be kept in order.

They may then be reinstalled in the same
ports, from which removed, if they are to
be used for further service.

1. Drain the cooling system and re-

move the cylinder head.

2. Remove the intake and exhaust

manifold assembly.

3. Remove the valve tappet cover, and
turn down the tappet screws several turns
so the springs may be removed easily
and t9 prevent interference with valve

stems after seats and faces are reground.

1-16

with a valve spring compressor (2) and
remove the valve spring seat keys (1).
Be careful not to compress the springs
more than necessary as they can be
distorted.

seats and valve springs. Be sure to keep

valves in order so they may be installed

in the same port.

camshaft must be removed.

Inspection

4. Compress the valve springs

5. Remove the valves, valve spring

~ : To remove the tappets the

-,~, ~ 7--Valve

':!;i~1ii,\:;~~:::::,',"""."",',':"".

Ql-J ~ Valve spring

Engine block ~ ~

Valve spring

seat key I

..(1.:);;:,;;:[,:'(!,

Valve guide

spring seat

Adjusting screw

Tappet

Tappet guide

Cam

General

Carbon deposits on the valves and valve

seats are normal and cannot be avoided
completely. However, such deposits are

detrimental to engine efficiency and valve

assembly life as the amount of carbon in
the engine increases.

The rotating mechanism (if equipped)
used on the exhaust valves greatly ex­tends the service life of the valves.

Valves and valve seats should be ex­amined for pitting, burning, warping and

other defects.

The formation of carbon cannot be avoided.
However, it can be held to a minimum by

the use of only good grade fuels and ac-

curate engine timing.

.--Valve

1-17

Camshaft

FfSM-32S2

Warpage, burning and pitting of valves is
mainly directed against the exhaust valves

which are exposed to the high temperature

flow of exhaust gases. Such defects are
generally caused by valves failing to seat
tightly and evenly, permitting exhaust blow­by. This, in turn, can generally be traced
to hard particles of carbon being present
on the slopes of the valve seats. It may,

however, be due to weak springs, insuf-

ficient valve clearance, or warpage and
misali.e;nment of the valve stem or guide.

Warpa~e, chiefly occurs on the valve stem
due to its exposure to heat. Out-of-round

wear occurs when the seat has been pounded
by a valve head which is not in line with its

stem or guide.

Misalignment is a result of wear, warpage,
and distortion. Wear, when accentuated by
insufficient lubrication, will eventually
create sloppy clearances with resultant

misalignment.

cylinder head bolts to the specified foot­pounds torque and in the sequence recom­mended. Valve clearances are also affected

in this manner. Thus any abnormal wear,warpage

or distortion affecting a valve
guide will destroy its function as an ac­curate bearing to maintain the valve head
concentric with its seat, and will prevent

leak-proof seating.

Oil and air sucked past worn intake valve
stems and guides into the combustion
chamber, cause excessive oil consumption,
form excessive carbon, and dilute fuel.

Examine the engine for signs which may

indicate the reason for the need of valve

reconditioning. Dry and rusted valve

springs are an indication that the oil pas­sages to the valve levers may be blocked,
causing wear on the valves and guides, and
resulting in improper valve action. A de-

fective gasket under the valve cover will

permit the entrance of dirt which will

cause undue wear on the valve stems andguides

and damage to the valve springs.

Warpage of the valves, and in known ex-

treme instances, that of the crankcase, can

result from the engine overheating due to a

blocked, dirty or insufficiently filled cool-

ing system.

Most frequE;'!ntly, however, warpage of a
valve stem or a guide is due to uneven tem­peratures being applied along its length.

The lower part of the guide and stem is

near the combustion heat, and the upper

portions are closer to cylinder head waterpassages.

Valve materials are carefully

chosen to withstand such varying tempera­tures. However, an engine that is allowed
to operate continually in an overheated con-

dition is definitely open to valve stem and
guide distortion and warpage. Distortion
can also be caused by failure to tighten

Valves

1. Remove all carbon from the valve

head and stem. Valve stems should be

lightly polished with an extremely fine
abrasive cloth sufficiently to remove the

carbon deposits only. Because of the
nature of the valve deposits, solvent clean­ing ordinarily will not remove all the de­posits from the valves. Wire brushes will
do this job satisfactorily, but only brasswire

brushes should be used since steel

brushes may scratch the surface. Such

scratches are likely to cause localized
stresses in an operating valve and may

eventually result in fatigue fractures of
the valve. For similar reasons the use of

coarse emery paper should be avoided.

1-18

2. Inspect each valve. See that the

stem is not worn excessively and that the

head is not burned or warped. Check the

WRONG

CORRECT

WRONG

FEA-64460

grooves in the stem to see that they have

not lost the shoulders through wear, which

prevents the valve seat retainer keys from

fitting snugly.

3. All valves having bent, worn, warped

or seriously pitted stems should be re-

placed. Replace any valve that cannot be

satisfactorily refaced with a definite mar-

gin maintained. The amount of grinding

necessary to true the valve face is a def-

inite indication of the valve head warpage

from the axis or centerline of its stem.

With excessive warpage, a knife edge will be
ground on part or all of the valve head due
to the considerable amount of metal that

must be removed to completely reface.

Maximum heaviness in a valve head is re­quired for strength and to provide as large

an area as possible for heat dissipation.
Knife edge valves lead to breakage and

warpage.

4. Clean and examine all valve springs
for rust, pitting, broken or set coils. Test
each spring against the spring specif\ca-

tions (see "Specifications II) using a spring
load tester. Replace all springs that do not

meet specifications.

5. Clean all valve spring seats with
solvent, and examine them for rust, cracks
and bending characteristics. Replace parts
as necessary.

Valve ::>eat Retainer Keys

Clean parts thoroughly in solvent. Check
the ribs in the inside of the keys to see that
none are worn sufficiently to cause loose-

ness. The keys must fit snugly into the

valve stem groove. Check the keys for
wear on the outside surface which might

allow the valve spring retainer to slide

over the key.

1-19

Valve Guides

Clean the bores of the valve guides, using awire

rifle brush and solvent. Blowout all
carbon with compressed air. Position a
light at the bottom of the guide bore, and

examine the walls for burning, cracking and

signs of excessive wear. Check the inside
diameter of the guide bore at several points
around its circumference and along its

length. Replace any guides considered un-

serviceable or that appear close to a
serviceable borderline.

~: All valve reconditioning equip-

ment requires the installation of a pilot in

the valve guide to produce a seat concentric

with the guide bore. For this reason the

guides must be clean and meet the engine

specifications before the valve seats can be
reconditioned.

Valve Seats

Remove all carbon and any remaining gas-

ket material from the crankcase surface.

Inspect all valve seats for cracks. Re-

move the carbon from the valve seat re­cesses or counterbores.

Rotocap

When the Rotocap is in operation, the valve
spring is compressed (valve opened), the

bellville washer is brought to bear on the

steel balls. This causes the balls to roll
down the ramp in the retainer thus rotating

the valve.

Testing Rotators

Use any valve spring tester and a steel
ball placed on an inner sleeve, then

rapidly oscillate the load.

You should perform this oscillation up tothe

test load indicated in "Specifications".

Be sure the rotator is lubricated internally.
The rotators should be cleaned, checked
and reinstalled at each overhaul period.

1-20

Observing the operation of the valves prior
to tear-down of the engine is beneficial in

preventing unnecessary checking of worn
rotators. Mark the valves with a pencil as

movement is relatively slight.

Reconditioning

Valve Guides

1. Press the g11ides from the crankcase.

2. Install new guides from the top of the
crankcase, and press them into the crank­case bores to a measured distance of
1-3/32 inch from the top surface of the
block to the top center of the guide.

3. All guides furnished as service
parts are reamed to size; however, as they
are a press fit, it is necessary to burnish

them after installation to remove any
possible burrs or slight distortion caused
by the pressing operation.

Valves

After being thoroughly cleaned and inspected,
valves that are fit for continued use should
be reconditioned as follows:

1. Set the valve refacing machine to
grind the specified angle of 45-1/2 degrees
and dress the grinding stone.

2. Insert a valve in the chuck and take
a light cut across its face. This is a check
to determine whether the valve can be re­conditioned to service standards with a cor-

rect amount of margin maintained. Warp-

age that may not be apparent in the visual
inspection will be clearly definable.

1-21

Avoid taldng heavy grinding cuts as this
heats the valve head excessively, producing

an unsatisfactory valve face, and necessi-

tates dressing the grinding wheel frequent-

ly. Repeated light grinding cuts are pre­ferred until a true face of even width is ob­tained around the valve. Avoid passing the

stone beyond the face of the valve as this

will cause ridging and grooving of the

stone surface and make dressing of the

stone necessary. Reject all valves with
distorted heads which produce an uneven
face and valves which grind down to a thin

edge.

One of the principal difficulties in recondi-

tioning valves is to obtain nearly identical

angles on the valve seat and valve face.
The importance of these angles in the
grinding operation cannot be overempha-

sized, because it is impossible to produce
a flat or square seat by lapping.

The grinding stones on both the valve re-

facing machine and valve seat grinder
should be dressed before starting a re-

conditioning job.

You will be unable to determine how closely
the angle of the seat will match the valve
face until the valve and seat have been

ground and a check made with a very light

tint of Prussian blue. If a full seat-width

contact around the entire circle of seated

valve is not shown, the angles do not match.

It will then be necessary to redress the

valve seat grinding stones, changing the

angle sufficiently to correct the error. The

correction should be made on the valve
seat, and not on the valve. No more

material should be removed from the valve

face than.is necessary to true it up and re­move the burned or pitted portion. New
valves should not be refaced, but should be
checked for trueness. When a satisfactory

match of valve seat and valve face angles
has been obtained, the adjustment of both
the valve refacer and the seat grinder should
be locked in position, in order to eliminate

this trial-by-error method on additional

valves having the same angle.

At times unusually large amounts of heat

scale may be found on exhaust valves,
which is hard on the grinding stone. Fre-

quent redressing of the stone will be neces-

sary to maintain a smooth even surface and

a uniform set of valve face angles.

After refacing each valve, inspect the end
of the stem. If wear is noticeable, reface

the end of the stem. Grind sufficiently to

true-up the end of the stem.

Perhaps it has been noticed that on many
International Harvester Farm Eq11ipment
engines, the valve face and seat are ground

to an "interference angle". This means

that the sum of the seat angle and the face

angle do not equal 90 degrees.

1-22

~;~'i":,

This is done to avoid the possibility of
grinding a reverse interference angle, and
to help prevent the accumulation of com­bustion deposits on valve faces and seats.

It is nearly impossible for anyone to grind

perfectly matching angles.

Grinding of valves to an interference angle
provides line contact of the valve face to
the seat for the first few hours of opera­tion, allowing the valve and seat to "wear
in" to a good tight contact. Interference

angle has the effect of increasing the pres-

sure per square inch on the seat, thus

causing any deposits which cling to the face

or seat to be squeezed out of the way and

eventually blown out.

Seats

The primary purpose of a valve seat is to

seal the combustion chamber against pres-

sure losses and to provide a path to dis-

sipate the heat accumulated in the valve

head so as to prevent burning of the seat

and warping of the valve head.

The location of the valve seat on the valve

face and its width, controls the amount ofvalve

head that protrudes into the com­bustion chamber. It is obvious that the
greater the exposure within the combustion
chamber, the higher the valve temperature;

or in other words, the more heat it will'
collect. High valve temperature and poor
heat dissipation also produce excessivevalve

stem temperatures. This will hastenthe

accumulation of carbon on the stems,

causing them to stick in the guides.

Valve

1-'23

Refacing Seats

Remove all carbon, scale and oil before

attempting to reface valve seats. The

grinding stone, when placed against an oily

seat, will become fouled, and uneven grind-

ing will occur.

~: Before installing the pilot, be

certain that the valve guides are perfectly

clean and meet the engine specifications.

This is important; otherwise, an eccentric

seat will be cut.

the stone to the correct angle.

Lightly lubricate and install the pilot of the
correct size into the valve guide bore.

to clear away grinding dust. Grind the

seat sufficiently to provide an even,
smooth surface.

Lower the grinder head over the pilot

shank until the stone just clears the valveseat.

Turn on the power and very gently
allow the stone to contact the valve seat.
Very little pressure other than the normal
weight of the stone should be used. Sudden

hard pressure can cause cocking of the

pilot in the guide and result in eccentric
grinding. Raise the stone frequently from
the valve seat to prevent overheating and

Correct Seat

Seat too wide

Check the seat concentricity, roundness

and valve face contact using Prussianblue.

Spread an extremely thin film of
this blue on the valve face and insert the
valve into its guide. With pressure on the

exact center of the valve head, make a
quarter turn rotation in the seat. Remove

the valve and inspect the impression made

upon the seat by the transfer of blueing,
and upon the valve face by the removal of

blueing. Check several times to guarantee

that no error was made. If a full seat-

width contact around the entire circle of

seated valve is not shown, the angles do

not match. It will then be necessary to re-

dress the valve seat grinding stones,
changing the angle sufficiently to correct
the error. The correction should be made

on the valve seat, and not on the valve.

The location of the area of contact between
the valve and the seat is a very important

factor in securing maximum valve life.

Seating the valve with the sharp edge of the

seat not contacting the valve face is un-

desirable. This sharp edge tends to break

off face deposits which may lead to valve
failure.

Dress

Seat too narrow

FEA-63042

FESM-32SS

Similarly, the location of the upper line of

contact well below the top of the valve face,
is also undesirable because a large over­hang prevents rapid cooling of the outer

edge of the valve.

After grinding the seats it may be found
that the seats are considerably wider than
the specified width of 3/64 inch. Valve

seats that are too wide may be narrowed
by grinding down the top edge of the seat

with a stone mounted on the grinder head.
The stone must be a smaller angle than
the valve seat (1~ preferably).

1-24

Reassembly

1. Coat the valve stems with engine

oil and insert the intake and exhaust

valves into their original positions.

2. Install the valve springs and valve

spring seats. Compress the valve springs

and install the valve seat retainer keys.
Release the springs and remove the valvecompressor.

4. Install the valve tappet cover using

a new gasket.

5. Install the intake and exhaust mani-

fold assembly using a new gasket. Tighten
the nuts evenly in steps to 20 ft. lbs.torque.

6. Install the cylinder head. Refer to

3. Adjust the valve tappets. Refer to

page 1-15.

page 1-14.

7. Refill the radiator with coolant.

CONNECTING RODS, PISTONS AND PISTON RINGS

General

Connecting Rods

The connecting rods serve as the links be-

tween the pistons and the crankshaft. The

surfaces of the rods must be kept free of

scoring and dents because of the high
stresses under which they function. The
rod has a bushing at each end, the one at

the upper end is a bushing for the piston

pin which anchors it to the piston. The
bearing at the crankshaft or lower end is
inserted in two halves which fit around
the crankshaft and are secured by a bear-

ing cap. The bearing cap is furnished
only with its connecting rod.

1-25

The lower bearings used in these engines
are the replaceable insert type and in­sure correct running clearances when

they are properly installed. This is pos­sible without boring. reaming, scraping

or using shims. The three important
fundamentals on bearings and bearing

fitting are "bearing crush," "bearing

spread," and "bearing clearance." An ex­planation of these will be covered later.

Pistons

The piston is one of the most important
units in the engine, and its condition has

much to do with the performance of the
engine. Its function is to receive the
force of the combustion pressure and

transmit it to the connecting rod and

crankshaft. The escape of combustion
pressure past the piston is prevented by
the piston rings. The fit of the piston and

rings in the sleeve must be close enough

to prevent the escape of combustion gases

but must be free enough to keep friction

to its working minimum.

Piston Rings
The pistons are fitted with three piston

rings. One oil regulating ring is fitted to
each piston. The oil regulating ring pro-

vides an even circulation of lubricating

oil and, therefore, an allover lubricating

and cooling action for the piston and

crankcase cylinder. Excess oil is wiped

by the rings, back down to the crankcase.

The remaining rings are compression
rings. Rings should be installed on a
piston so that the gaps are 90 degrees

from the thrust side of the piston and 180

degrees from one gap to another.

Piston Pins

The piston pin is made of steel and is

cylindrical in shape. Its purpose is to

anchor the piston to the connecting rod.

The pin is retained in the piston by re-

tainer rings that lock into grooves of the

piston pin bore. The pin is allowed to
float in its bushing in the upper end of the
rod. It is usually necessary to heat the
piston in order to remove the pin.

Cylinder

ridge

Worn rings
fit ridge

New ring
interference

Removal

1. Remove the cylinder head. (Refer

to page 1-13.)

2. Remove the drain plug and drain
the engine lubricating oil from the crank­case oil pan. Replace the drain plug.

3. Remove the cap screws securing

the oil pan, and remove the oil pan and
gasket.

IMPORTANT: Before proceeding with
piston and connecting rod removal, the
ridge, existing on the cylinder wall at the
upper end of the ring travel, must be re­moved by using a ridge reamer. This
prevents damage to the piston ring lands

during removal of pistons, and prevents

damage to new top piston rings after the

installation of new rings.

FESM-3257

1-26

>!~t;Z;-..,

",..~"..

\!:':!:!:

4. Remove the oil pump screen and

tube assembly.

5. Remove the connecting rod bearing

cap nuts. Remove the bearing cap. Be
sure that each bearing and cap can be
identified with the connecting rod from

which it was removed. Each connecting
rod should be found numbered on the carn-

shaft side of the rod, indicating its posi­tion in the engine.

IMPORTANT: Pistons must be handled

carefully to avoid damage and knocking
out-of-round or alignment. When re­moving a piston from the crankcase, do

not allow the skirt of the piston to strike
the crankcase or connecting rod. Mark
the pistons so they can be installed in the

same position and cylinder from which

they were removed. The dome of the

piston is stamped with an arrow, indi-

cating its position when properly installed.

6. Push the connecting rod and piston

assembly to the top and lift out from the
crankcase. Replace the cap on the con­necting rod to avoid damage.

Disassembly

7. Crank the engine by hand to make

each rod and cap accessible and remove
all pistons and connecting rods in the
same manner.

1. Remove the piston rings with a
piston ring expander. Remove the top
ring first and the remaining rings inorder.

2. Remove the piston pin retainer

rings.

3. Remove the piston pins from the

pistons. As an aid in removing the pin,
heat the piston in hot-to-boiling water
and then remove the pin, being careful

not to damage the piston.

1-27

nspection and Repair

1. Wash all parts in a cleaning solvent.

Clean the carbon from the piston ring

grooves with a broken ring or ring groovecleaner.

2. Inspect the connecting rods, caps,

bearing shells and pin bushings as

follows:

(a) All connecting rod bearings and

piston pin bushings should be replaced in
a major overhaul.

(b) Test rods for alignment. Rods
only slightly misaligned can be straightened
using the proper equipment. Badly twisted

or bent rods must be replaced.

3. Inspect the pistons for cracks,

breaks or scores.

4. Measure the piston skirt at right

angles to the pin to determine if it is

worn excessively; replace if necessary.
The specified piston diameter is 2.6230

to 2.6234 inches.

~: On a used piston, it will prob­ably be found that the piston ring side
clearances tend to increase toward the
top of the piston due to the higher oper­ating temperature prevalent at this point.
\Vhen this side clearance becomes exces­sive, the piston will have to be replaced.

5. Measure the crankcase cylinder
bores for excessive wear. The specified
bore ill is 2.625 to 2.627 inches. Replace-

ment pistons are available in .020 and

.040 inch oversizes.

6. Inspect the piston pins for wear; if
wear is perceptible, replace pins. Re­place piston pins showing signs of cor-

rosion or etching. Specified piston pin

diameter is .6875 to .6876 inch.

7. Inspect the connecting rod bushings

for scratches and burrs. Replace ifnecessary.

8. Connecting rod bolts must be

cleaned of all foreign matter including

the anti -rust materials that may be caked

in the threads. This is also true of the
connecting rod bolt nuts.

A good method of checking to determine

thread condition is to turn the connecting

rod bolt (threads lubricated mth a light
engine oil) all the way into a standard nut

mth the fingers. If the bolt runs in rela­tively free mthout sticking or mthout the

need for applying more than a very light

(2-4 foot-pounds) wrench effort, the bolt

is satisfactory for use.

9. Rings should be checked also for

the specified side clearance by measuring
the clearance between the piston ring and

the piston ring land as shown.

1-28

I

10. Inspect the piston rings for damage.

Faulty rings cannot always be detected by

the eye. Engine performance and irregu-

larities such as excessive oil consumption

must be taken into consideration. Where-

ever there is doubt as to the serviceability
of the piston rings, it is advisable to re­place such parts.

11. Insert each ring into the cylinder

bore for that piston. Force them squarely

down inside the sleeve or cylinder bore.

Position a feeler gauge between the ends of

the ring, and compare the existing gap

against the specified gap. If it is neces-

sary to remove material from the ring

ends because the end gap is too close,

clamp a mill file in a vise, hold the ring in

proper alignment and dress off the ends

squarely to obtain the desired gap.

12. Inspect the "windows" of the oil

regulating ring and piston for blocked oil-

ways. Failure to keep the oilways clear

will result in uneven lubrication and "hot-

spots" of the piston and cylinder sleeve.
All rings should fit loosely in the piston
grooves without binding.

13. Place connecting rods in an arbor

press and press old piston pin bushings

from the connecting rods.

14. Align the new piston pin bushing on
the connecting rod so that the oil hole in
the bushing will match with the oil hole in
the connecting rod. Press the bushing into
the rod.

15. Press the bushing into place in the

connecting rod and then ream to provide
the specified piston pin clearance of .0003
to .0007 inch.

1-29

Reassembly

1. Before assembling the piston and
connecting rod, check the fit of the piston
pin in the piston for proper end clearance

as follows:

(d) Using a feeler gauge, in the gap

between the piston pin and the retainer

ring, check for end clearance. Specified
end clearance is .010 to .030 inch.

(e) Remove the retainer rings and

proceed with the assembly as follows:

(a) Prepare the piston and the pin

for assembly as outlined in Step 2.

(b) Push the pin into the piston and

install a retainer ring at each side of the

piston.

(c) Push one end of the piston pin
until it stops against the retainer ring on
the opposite side of the piston.

Top ring

Inner groove up

Lower ring

Outer groove down

Oil control
ring

~: When assembling the pistons tothe

rods, the front of the piston will be

indicated by an arrow.

2. With the piston pin at room tempera­ture (700) and generously coated with clean
engine lubricating oil, and the piston heated

in hot water to approximately 1500F the pis­ton pin can be entered into one boss of the
piston by pushing with the hand. While the

piston is hot, quickly and correctly position

the connecting rod inside the piston, align

the bushing in the rod bore with the piston

pin holes in the piston and push the piston
pin completely into position. Thoroughly
dry the piston with compressed air.

3. Install a retainer ring in the groove

at each side of the piston to secure the

piston pin.

FESM-326 I

4. Using a piston ring expandert install
the ringst oil control ring firstt into the
grooves of the pistons.

Position the ring gaps 90 degrees from the
thrust side of the piston (in line with the
piston pin bore) and 180 degrees from one

gap to another.

Be sure the compression rings are in­stalled with their grooves positioned as

shown.

1-30

Piston Fit in Bore

Specified piston-to-bore clearance is .0016
to .0024 inch and can be determined using

a 1/2 inch wide feeler gauge and a spring-type

tension scale (FES 108).

The thickness of the feeler gauge that canbe

removed with a 2 to 8 pound pull repre-

sents the piston-to-bore clearance as out-lined

in the "Piston Clearance Chart."Clearances

should conform to specifications.

The chart shows the relationship between

the feeler gauge thickness and pounds pull

in measuring piston-to-bore clearance.
Note that with a given feeler gauge thick-

ness the actual clearance is less than the

feeler gauge used when the pound pull is

towards the high side of the pound pull

range. This is especially true with the
thinner feeler gauges.

determine piston-to-bore clearanceproceed

as follows:

1. Select a feeler gauge (free of dents

or burrs) of one of the thicknesses listed

in the chart. Position the feeler gauge inthe

cylinder bore so that it extends theentire

length of the piston 900 from the

piston pin location.

Pull

inLbs.

2
4
6
8

PISTON CLEARANCE CHART

Feeler Gauge Thickness

.00151.002

.003

.00351.004

.0045

Clearance in Inches

.00161.00221.00331.00391.00441.005

.00131.00181.00291.00351.004

.001

.0046

2. Invert the piston and install it in the

bore so that the end of the piston is about

1-1/2 inches below the top of the cylinder
block and the piston pin is parallel to the

crankshaft axis.

3. Hold the piston and slowly pull the

scale in a strai~ht line with the feeler

gauge, noting the pull required to remove
the feeler gauge. Check three times and

record the average of the three readings

obtained. Do not bend or kink the feeler

gauge.

4. Refer to the chart to determine the

actual clearance. The clearance is shownwhere

the horizontal column indicatingpounds

pull and the vertical column indi-cating

the thickness of the feeler gaugeused

intersect.

EXAMPL~: If a .003 inch feeler gaugeis

used and it takes 8 pounds pull to removethe

feeler gauge, the clearance is .0023 inch.

To

.00151.00261.00311.00361.0042

.0008/.00131.0023/.00281.00331.00381-31

5. Repeat step 3 with the piston at right
angles to the crankshaft axis. Determine
the clearance as instructed in step 4.

6. Measuring piston-to-bore clearance
with the piston pin parallel and at right
angles to the crankshaft axis will reflect

any "out of round" in the bore.

Bearing Fitting Procedure

C_AUTION: Bearings or bearing caps

must not be filed, lapped or modified in any
manner to reduce journal-to-bearing clear­ance. Premature bearing failure will re-

sult from attempts to reduce journal-to-

bearing running clearances. While such
methods will make a tighter fit at the top

and bottom of the bearing, it will result in

an out-of-round bore and distortion of the
bearing shell. New bearing shells will
have to be installed eventually and addi-

tional problems will be encountered. Such

modification alters the engineered fit of

the bearing shells in their bores and de-

stroys the desired "crush".

1. When installing precision type bear-

ings, it is important that the bearing shells

fit tightly in the rod or crankcase bore. To

accomplish this, the diameter of the bear­ing at right angles to the parting line is

slightly larger than the actual diameter of
the bore onto which the bearing will be
assembled. When the bearing cap is drawn

up tight the bearing is compressed, assur-

ing a positive contact between the bearing

back and bore. The increased bearing

diameter is called "bearing crush".

1. Bearing locking tangs

Be certain the bearings are fully seated

and the locking tangs (1) on the bearings

fit into the recesses.

2. To assemble the bearings with the
correct "bearing crush," tighten the clamp­ing bolts alternately and evenly to the
specified torque with a torque wrench.

1-32

SOFT MALLET (STRIKE LIGHTLY

AND SQUARELY)

BEARING

FEA.63050

~:;;:;;~~~

WOOD BLOCK

3. Main and connecting rod bearings

are designed with the "spread" (width
across the open ends) slightly greater than

the diameter of the crankcase bore or

connecting rod bore into which they are to

be assembled. For example, the width

across the open ends of the connecting rod
bearing not in place is approximately .025

inch more than when the bearing is in posi­tion in the rod. This condition causes the
bearing to fit snugly in the rod bore and the

bearing must be "snapped" or lightly

forced into its seat.

Rough handling in shipment, storage, or

normal use in an engine, may cause the

bearing spread to be increased or de­creased from the specified width. Bearing
spread should therefore be carefully meas-

ured and corrected as necessary before

installation in an engine. Bearing spread
can be safely adjusted as follows if care
and judgment are exercised.

(a) EXCESSIVE SPREAD: If meas-

urement of bearing indicates that dimension

"A " is excessive, place bearing on a wood

block and strike the side lightly and square-

ly with a soft mallet. Recheck measurement
and, if necessary, continue until correct
width is obtained.

~

DECREASING SPREAD

(b) INSUFFICIENT SPREAD: If
measurement of bearing indicates insuf­ficient spread, place bearing on a wood
block and strike the back of the bearing
lightly and squarely with a soft mallet.
Recheck measurement and if necessary
continue until correct width is obtained.

1- 33

4. BEARING CLEARANCE: When in-

stalling bearings in an engine, the proper
clearance between bearing surface should
be checked closely. Specified bearing

clearance is .002 to .003 inch. To get an

accurate measurement of this clearance,
the IIPlastigage II method, or virgin lead,

(a) Remove bearing cap and wipe

bearing surface and exposed half of crank-

shaft journal free of oil.

(b) Place a piece of "Plastigage" the

full width of bearing insert.

can be used. The following instructions

can be used when measuring with
"Plastigage":

(c) Reinstall the bearing cap and

tighten the self-locking cap screws to 16
foot-pounds torque.

(d) Remove the bearing cap. The
flattened plastic material will be found ad­hering to either the bearing shell or the
crankshaft.

(e) To determine the bearing clear­ance, compare the width of the flattened
plastic material at its widest point with
the graduations on the envelope. The num­ber within the graduation on the envelope
indicates the clearance in thousandths of an

inch.

(f) If using virgin lead, carefully re­move the flattened lead and measure its
thickness with a micrometer.

~: Do not turn crankshaft duringthe

above procedure.

Should the readings not fall within the speci­fied limits, and the torque wrench is known
to be accurate in its measurement, remove
the bearing from the connecting rod and
replace it with a new one. However, with
the precision bearings used, no difficulty
should be encountered providing the crank-

shaft and/or connecting rod are in proper

condition.

1-34

Installation

I. Cyl indor numbor toward camshaft I

NOTE: When reinstalling a piston and
connecting rod assembly, install the as­sembly in the same cylinder bore and in

the same position from which it was re­moved. Connecting rods are stamped with
the cylinder number on one side of the rod

and on the same side of the bearing cap,
No.1 starting at the front end of the en-

gine. Be sure to install the numbered
side of both the rod and bearing cap so
both are on the camshaft side of the

engine.

1. Generously coat the piston ring
compressor and bore with lubricating oil.
Install the ring compressor on the piston
and insert the piston and connecting rod

assembly through the top of the crankcase.'

2. Push down on the piston carefully

until it is in the crankcase bore.

3. Wipe clean and oil the crankshaft

journals and fit the connecting rod bear­ings as outlined in "Bearing Fitting

Procedure."

4. Install all the pistons, connecting

rods and bearings in the same manner.

5. Check the connecting rod side

clearance by inserting a feeler gauge be­tween the bearing cap and lobe of the
crankshaft. The specified side clearance

is .005 to .012 inch.

6. Install the oil pump screen and

tube assembly.

7. Install the crankcase oil pan and

new gasket. Fill the crankcase to the

level on the gauge with the grade of

engine oil specified in Operator's manual.

8. Install the cylinder head and

gasket. (Refer to page 1-14.)

1-35

I

Crankcase Cylinder Re-Boring Procedure

This section covers re-boring of the cyl-

inder bore with the engine disassembled.
However, if re-boring is the only service
to be performed on the engine, the crank­shaft need not be removed.

When to Re-Bore

Replacement piston ring kits may be used
to extend the life of the piston if cylinder

wear has not been excessive. Inspect cyl­inder bores for scoring and roughness
which indicate excessive wear. Check cyl-

inder bores for taper and out-of-round by
the use of a cylinder gauge placed at the
top, middle, and bottom of bores, both
parallel and at right angle to the centerline

of crankshaft. To be within safe limits, the

taper from top to bottom of the ring travel

area must not exceed 0.005 in. and the out-

of-round (egg-shape) condition must not

exceed .005 in. in the cylinder bores. If
the bore is worn beyond these limits, a

re-b~ring job is required. It is advisable
to re-bore for the smallest possible over­size pistons and rings. If only one or two

bores require correction, it is not neces-

sary to re-bore all cylinders to the same

oversize.

Preparing the Block

Clean the water jacket with materials that

will remove rust and scale and then flush

thoroughly. Degrease the crankcase so

that the abrasive material from the boring
operation may be completely removed

before reassembly.

Before setting up a boring machine on the

block, the top of block must be carefully

cleaned to remove all foreign materials,

such as carbon, rust, or gasket cement.
Use a 14 in. fine-cut, mill file to draw-file
the block for removal of all burrs and high

spots around the top edge and bolt holes.
This will provide a smooth, true working
surface for the boring operation. This is
very important because the alignment of

the cylinder bores depends entirely on the

tightness of this working surface.

1...36

Re-Boring

When re-boring cylinders, all crankshaft

bearing caps must be in place and torqued

to specifications to avoid possible distor­tion of bores in final assembly. If all bores
require the same correction, to save time

bore the cylinder having the greatest

amount of wear and taper first. If this

cylinder cleans up to the smallest desired
oversize, you can be sure that the remain­ing, smaller cylinder bores will clean up
to the same size. Oversize pistons fur­nished for service are .020 in. and .040 in.

oversize. No attempt should be made to

cut down oversize pistons to fit cylinderbores.

Use a good single point boring bar with a

sharp tool and bore all cylinders the same
size, to within .002 to .001 in. of the de­sired finished oversize to permit finishing

honing operations.

Honing

For best results, hone the cylinders to the
finished size. This operation must re­move all boring tool marks. Final finish

should be in the range of 20 to 35 micro­inches. If you have no means for measur­ing the finish, the use of about 120 ~rit

stones will produce approximately the

correct finish.

To center the boring machine on each
cylinder, follow closely the instructions of

the boring machine manufacturer.

~: If the crankshaft has not been

removed, be sure the crankshaft is out of

the way of the boring cutter when boring

each cylinder.

Cylinders that are too smooth will retard

run-in and may result in ring scuffing.

When cylinders are too rough, rapid ring

wear will result. A rigid type wet hone is
preferred for the final sizing operation, but

a spring hone of the glaze-breaking type

may be used if the other is not available.

Spring hones should be equipped with 220

grit stones and stock removal should not

exceed 0.003 in. This type of hone should
be dipped into SAE 10 or 20 lubricating oil
before beginning the operation. Dull or

dirty stones cut unevenly and generate ex­cessive heat. Keep honing equipment sharp
and clean. When finished honing, pass the

hone through the entire cylinder bore at a

rate of 60 cycles per minute or as neces-

sary to provide a 30 degree (relative to the
top of the sleeve) cross-hatch pattern on

cylinder walls. This will insure maximum

ring life and minimum oil consumption.

1-37

The success of any re-boring job depends
on the accuracy and smoothness of the

finished bores, the amount of piston clear-

ance, and the thoroughness with which you
clean the block and crankcase of all cut­tings and abrasive materials resulting

from boring and honing. The best re­boring job will be a total loss unless the
crankcase is thoroughly cleaned. Foreign
material which remains causes rapid
wear of pistons, rings, and cylinder walls,
and will seriously damage engine bearings.

Checking Clearance

Refer to "Piston Fit in Bore", page 1-31

For thorough cleaning of the crankcase,

washing in a tank of hot, agitated clean-

ing solution is the recommended proce-

dure. If this cannot be done, use a good

cleaning solution and air pressure blast
followed by careful wiping with clean
cloths and light lubricating oil. Surfaces

should be wiped until a clean cloth shows
no discoloration. Wash and blowout oilpassages.

TIMING GEAR TRAIN AND FRONT COVER

The crankcase front cover encloses the
timing gear train. It is of one piece con­struction. It also provides mounting for

the governor and ignition drive. The

Removal

1. Support the engine and remove the

radiator, steering gear housing assembly
and front axle from the tractor.

Remove the cooling fan assembly

General

gear train is comprised of the crankshaft
gear, camshaft gear, idler gear and the
ignition l.U1it and governor drive gear.

3. Remove the distributor and dis-

tributor drive.

2.

(3).1-38

4. Remove the engine governorassembly.

5. Remove the fan drive pulley
from the crankshaft using removing tools
FES 33-1 and a two jaw puller as shown.

NOTE: If the fan drive pulley has a

wear sleeve installed, inspect the sleeve

for excessive wear or damage. To re-

move the wear sleeve,indent the sleeve

surface li.e;htly with a blunt chisel. This
will expand the sleeve for easy removal.

GSS-1411 (Rev. No.1)

1-39

Printed in United States of America

6. Remove the cap screws from the

front cover, and remove the cover and
gasket. Clean the gasket mating areas
to insure proper sealing when re-

assembled.

7. Remove the idler gear shaft bolt

and remove the idler gear.

8. Remove the crankshaft gear with a

puller.

~: Before removing any gears it
is advisable to check the backlash of the
gears to determine which, if any, require

service. Check the backlash with a dial

indicator or feeler gauges. The speci-

fled backlash is .003 to .006 inch.

1. Clean all parts thoroughly in a

cleaning solvent and dry with com-

pressed air.

2. Remove all gasket material from
the crankcase and front cover with a
putty knife so that a clean surface can be

had when the new gaskets are installed.

Reassembly and Installation

9. Using a puller, remove the cam-

shaft gear.

10. Remove the ignition drive seal.

3. Inspect all gears for excessive

wear, chipping or cracks.

4. Inspect all keys and keyways for

wear or damage and replace as

necessary .

5. Be sure to install a new front

cover oil seal and gasket.

1. Install a new ignition drive oil seal
in the crankcase. The seal must be
square in its bore and positioned 23/32
inch from the ignition mounting flange

face.

2. Install the key in the camshaft if

it was removed. Heat the camshaft gear

in boiling water. Install the camshaft
gear on the shaft with the timing marks

facing out.

GSS-1411 (Rev. No.1) Printed in United States of America

1-40

l8-tooth

CronKshoft

3. Install the key in the crankshaft if it

was removed. Heat the crankshaft gear

and install the gear, being sure the single
timing mark of the camshaft gear and the
single mark on the crankshaft gear are

aligned.

4. Install the idler gear and shaft.

Tighten the bolt to 90 ft. lbs. torque. The

idler gear is correctly timed by lining up

the double punch mark on the idler gear

with the double punch mark on the crank-

shaft gear.

FESM-3267

~ : Before installing the crank-

case front cover, mark the top surfaces

of the two teeth on each side of the §l!;!g!f:
punch mark on the idler gear with chalk.

5. Install the crankcase front cover

with a new oil seal and gasket. po 1!.QL
tighten the cap screws at this time.

NOTE: If necessary, install a new

wear sleeve onto the fan drive pulleyusing

the FES 33-4 fan drive pulley wear

sleeve installer as shown. Be sure to

apply a sealer onto the pulley O. D. or the
I. D. of the wear sleeve before installing
the wear sleeve onto the pulley.

6. Install the fan drive pulley (1) using

installing tool, FES 33-1 as shown. It

may be necessary to block the flywheelto

prevent the crankshaft from rotating.

7. Tighten the front cover cap screws

to 20 ft. lbs. torque. This permits the

seal and the cover to be centered by the

fan drive pulley hub and insures an even

contact of the seal around the pulley hub.

GSS-1411 (Rev. No.1)

1-41

Printed in United States of America

~: Before installing the governor

assembly, mark the front surface of the

ignition drive gear having a single punch
mark with chalk.

8. Install the governor assembly with

a new housing gasket. Time the ignition

drive gear as follows:

With the engine on top dead center of
number 1 firing stroke, mesh the marked
tooth of the ignition drive gear with the

two chalk marked teeth on the idler gear.

9. Position the ignition unit distrib­utor arm and drive shaft lug (A) for firing
number one cylinder. Install the ignition
unit on the engine, meshing distributor
lug (A) and governor drive slots (B).

~: Remove the secondary cables

from No.2, 3 and 4 spark plugs to pre­vent any chance of accidentally starting
the engine.

1-42

10. Place the number one spark plug
cable in a position so that the spark to
ground will be audible when hand crank-

ing the engine. Then advance or retard
the ignition distributor until spark occurs
as the T .D.C. mark (1) on the fan drive
pulley (3) aligns with pointer while ~
cranking engine. Never time the spark
before top dead center.

~ : Final ignition timing must be
made with a timing light. The specified
ignition timing is 16 degrees (2) before

T .D.C. at 2000 engine rpm.

11. Install the cooling fan assembly.

(Refer to page 1-62.)

12. Install the radiator assembly,

steering gear housing assembly and

front axle on the tractor.

CAMSHAFT

The camshaft is a single piece, drop
forged shaft, with three bearing journals.

The journals are supported by the

machined bores in the crankcase. A

helical gear, keyed to the shaft at the

forward end of the camshaft is driven by
the crankshaft.

The camshaft operates at one-half the

engine speed.

General

The camshaft extends through the rear
bearing bore into the oil pump body. This
extended portion of the shaft is smaller in

diameter than the rear bearing journal

and carries a Woodruff key to drive the

oil pump drive gear.

The camshaft has the main function of

operating the intake and exhaust valve
mechanism, by action of the lobes upon
the valve tappets during rotation.

1-43

Removal

of the camshaft only, requires

the removal of the engine from the

tractor and removal of head, valves, oilpan,

oil pump, flywheel and crankcase

front cover from the engine.

2. Remove the flywheel, and remove
the oil pump body and gears. Refer to
page 1-55. Remove the key in the rear of
the camshaft.

3. Remove the crankcase front cover.

Refer to page 1-38.

4. Remove the two cap screws in the
camshaft retainer plate through openings

in the cam drive gear.

5. Turn the crankcase upside down so
the tappets (1) will fall away from the

camshaft to provide clearance for re-

moval.

6. Withdraw the camshaft (2) from the

front carefully so the crankcase bores
are not damaged by nicks from the edges
of the cam lobes.

7. If necessary to remove the cam-

shaft gear (3), press the gear off.

8. Remove the thrust plate and key if
the camshaft gear was removed.

1. Remove the valve tappet cover, and

remove the valve assemblies. Refer topage

1-16. Be sure to identify each as-

sembly for proper reassembly.

I nspection and Repair

1. Clean all parts in a cleaning
solvent and dry with compressed air. As
inspection is completed, coat each part
with clean engine oil and store safely
until reassembly.

2. Inspect the camshaft journals for
excessive wear. The specified journal
diameters are 1.871 to 1.872 inches for

9. Lift the valve tappets out of thecrankcase.
Be sure to identify the

tappets so they can be installed in their
original bores.

the front, 1.746 to 1.747 inches for the

center and .872 and .873 inch for the rear

journal. If excessively worn or out-of-

round, the camshaft must be replaced.

Check any run-out on the camshaft using

a dial indicator at the center bearing

journal. Place the shaft in a lathe or be-

tween centering blocks. The total run-

out must not exceed .002 inch.

1-44

Removal

3. Check the crankcase bearing bore

inside diameters. The specified ill is

1.8740 to 1.8755 inches for the front, 1.7490to

1.7505 inches for the center and .8740 to

.8755 inch for the rear.

4. fuspect the camshaft lobes for ex-

cessive wear, chipping, scoring and re­place if necessary. If the lifting areas of
the cam lobes, when compared with new

camshaft, show amount of wear exceeding

.020 inch, the camshaft must be replaced.

If a new camshaft is not available for com­parison, the cam lobe wear can be meas­ured with a micrometer in the following
manner. Take a reading across A-C and

deduct the reading B-D; this will give the
lobe lift. When the cam lobe wear limit

has been reached, this lift will be .020 in.

less than the specified lift of .232 inch.
The camshaft must then be replaced with
a new one.

5. Replace the camshaft gear if the
teeth are excessively worn, chipped or
scored. Small nicks or burrs can be re­moved with a hone or fine mill file.

6. Check the condition of the thrustflange

and replace if excessively worn.

7. Inspect the tappets. Replace any

that are scratched or worn.

8. Be sure to use new gaskets in re-

assembly.

Installation

1. Install the valve tappets in their

original bores.

2. Place the camshaft thrust plate on the
shaft and install the key in the keyway. Heat

the camshaft gear in boiling water and install
the gear (with the timing mark facing out).

3. Check the end clearance with a
feeler gauge between the camshaft frontjournal

and the thrust plate. Be sure thedrive

gear is in place against the shoulder

on camshaft. The specified end clearanceis

.003 to .012 inch. If the end play is ex-cessive,

replace the thrust plate with a

new one.

1-45

4. Coat the camshaft with engine oil
and install the camshaft in the crankcase.
Be sure the camshaft gear (3) is cor-

rectly indexed with the timing mark on

the crankshaft gear (2).

5. Secure the thrust plate to the crank­case and tighten the cap screws to 20 ft.
lbs. torque. Access to each of the two

screws is through the holes in the carn-

shaft gear.

6. Install the front cover and fan drive

pulley. Refer to page 1-40.

7. Install the key in the rear of the

camshaft, and install the oil pump gears
and body. Install the flywheel.

8. Install the valve assemblies andhead.

Refer to page 1-25.

9. Install the oil pan.

10. Install the engine in the tractor.

Refer to page 1-12.

11. Install the steering gear housing

assembly, front axle and the radiator

assembly on the front of the engine.

12. Start the engine and bring up to

operating temperature.

(a) Inspect for oil leaks and check

for correct engine oil pressure.

(b) Check and adjust the ignition

timing .

(c) Check and adjust the valve

clearance if necessary. Refer to
page 1-15.

1-46

CRANKSHAFT AND MAIN BEARINGS

The crankshaft is supported in the crank­case by replaceable insert bearings. The

precision-type bearings are not adjust-able.

When running clearances becomeexcessive,

replacement is necessary.

The connecting rods and all crankshaft
journals are rifle-drilled to provide

positive lubrication. Each main bearing

cap, which contains the lower half of the

insert bearings, is numbered consecutively
to correspond with a number stamped on
the camshaft side of the crankcase. The
bearing caps are not interchangeable.

No.1 bearing cap is at the front of the

engine.

CAUTION: Extreme care must be

taken to guarantee cleanliness of the

crankcase, crankshaft and bearings after

service has been completed. Whene.ver
possible, the crankshaft should be re­moved when new bearings are being in­stalled in order to clean the crankcase
thoroughly. AIl bearing surfaces must

be free of grit and burrs. Small particles

of dust and dirt left between the crank-

shaft and bearings will cause rapid wear
and scoring of the crankshaft journal and

insert. Any foreign material left between

the bearings and the crankcase and bear-

ing caps will cause distortion of the bear-

ing and a reduction in operating bearing
clearance at localized point. The fric-

tional heat thus produced will in turn

cause the bearing material to melt away

from the steel back of the bearing at that
point. Such melted material wiIl create

further hot spots until complete bearing

failure takes place. Anything that inter-

feres with the operating clearance of any

bearing or the proper heat dissipation has

its effect upon bearing life. Cleanliness

cannot be overstressed.

The crankshaft front and rear oil seals

will also be worn and should be replaced.
This cleaning of the crankcase and re­placing of oil seals is the best insurance
against early bearing failures through

dirt or foreign material left in the crank­case oil distribution bores or from dirt

entering worn oil seals.

Main bearings are available in standard
production size for new shafts or for used

shafts having little or no wear and .002

inch undersize for shafts slightly worn.
Also available are .010, .020 and .030 inch
undersize for use with regound crank-

shafts. When servicing main bearings,
one defective bearing will require the re­placement of all three bearings; otherwise
crankshaft "lay" or alignment cannot be

maintained.

The replacement of crankshaft main bear­ings without removing the crankshaft
should be done 2!Y.Y. in an emergency.
When these bearings are worn sufficiently

to require replacement or have failed

through lack of lubrication, the entire

crankcase and its oil distribution bores
should be thoroughly cleaned. This can-

not be accomplished without the removal
of the crankshaft.

General

1-47

Removal

To completely service the crankshaft and
bearings, the crankcase oil, cooling and
hydraulic systems must be drained and
the engine removed from the tractor.

Refer to page 1-10.

1. Remove the fan drive pulley. (Refer

to page 1-39.)

2. Remove the front cover. (Refer topage
1-38.)

3. Remove the flywheel and the rear

oil seal retainer.

4. Remove the crankcase oil pan, and

remove the oil pump screen and tube.

5. Remove the crankshaft bearing cap
bolts. Tap the caps lightly with a lead
hammer, if necessary, to dislodge them

and remove squarely from position.

6. Remove the lower bearing from

each cap. If they are to be reassembled,

be certain that they are identified as to

their original positions. Wrap them in
clean cloths and store until reassembly.

NaTE: If the crankshaft is to be re-moved

disregard step 7.

7. Remove the upper bearing halves

from between the crankshaft and the

crankcase with a thin piece of flexible

soft sheet metal. Push against the end

of the bearing without the positioning nut,

while turning the crankshaft in the direc-

tion of rotation. The bearing will slide

from position easily.

8. Remove the connecting rod bearing

cap nuts and bolts and remove the caps.

Push the piston and rod assemblies to the

top of their travel.

9. Lift the crankshaft out of the crank-case.

1-48

nspection and Repair

1. Clean all parts with cleaning solvent

and dry with compressed air.

2. Inspect the bearings for wear and
evidence of uneven bearing support. Ex­amine the bearing caps and supporting
surfaces of the crankcase for high spots
and burrs.

3. Inspect the crankshaft journals for
scoring and measure the diameter of each

journal with a micrometer. Specified
journal diameter is 1.623 to 1.624 inches.

Measure each journal at two points, one

at right angles to the other, in order to

detect any out-of-roundness.

Move the micrometer over the entire

width of the journal.

4. Check the connecting rod journals
for out-of-round condition. Use a micro­meter and take measurements at least
three places around the journals. The
specified rod journal diameter is 1.498
to 1.499 inches.

5. Inspect the crankshaft gear teeth

for excessive wear and chipping. If

necessary to replace it, pull the gear

with a puller.

6. Inspect the crankcase for sludge

and deposits and thoroughly clean it.

7. Replace all seals and gaskets with

new ones.

1-49

I

Installation

1. Wipe all surfaces of the crankshaft

bearing bores of crankcase and bearing
caps free of oil, and place bearing halves

in the bore of the crankcase and bearing
caps. Be certain the bearings are fully
seated, oil holes are in alignment, and

locking tangs on the bearings fit into the

recesses.

2. Apply a film of engine oil on the

bearing surfaces and place the crankshaft
into position.

NOTE: \Vhen installing the crankshaft,

be certain to correctly index the timing

marks on the crankshaft gear with the
idler gear and camshaft gear.

3. Install the bearing caps over the

crankshaft journals, being certain to in-

stall the caps in their correct positions

and with the numbered side of the caps tothe

camshaft side of the engine.

4. Check the main bearing clearances

as follows:

(a) Remove the bearing cap and wipe
the bearing surface and exposed half of the
crankshaft journal free of oil.

(b) Place a piece of "Plastigage" or

virgin lead, the full width of the bearing

insert, on the crankshaft journal.

(c) Reinstall the bearing cap and

tighten the cap screws to 55 foot-poundstorque.

1-50

(d) Remove the bearing cap. The

flattened section of the virgin lead or

IIPlastigage II represents the clearance

present between the bearing surface and
the crankshaft journal. Measure the thick­ness with a micrometer or match the

flattened Plastigage at several points

(on either the bearing insert or the crank­shaft), with the corresponding graduation
on the Plastigage envelope, which indicates

the clearance in thousandths of an inch.

Running clearance must be .002 to .003 inch.

~: Do not turn the crankshaft dur-

ing the bearing clearance check.

(e) Should the readings not fall
within the specified limits, and the torque
wrench is known to be accurate, remove
the bearing and replace it with a new one.

However, with the precision bearings used,
no difficulty should be encountered provid-

ing the crankshaft and/or crankcase and

caps are in good order.

5. Install the bearing caps to their
original position and tighten the cap screws
to 55 ft. lbs. torque.

~: When installing center main

bearing cap, hold crankshaft against the

rear thrust face of the upper half of the
bearing. Tighten center cap bolts lightly
and tap cap toward the rear before final
tightening of cap bolts. This lines up the

upper and lower thrust surfaces of the bear­ing halves and prevents binding the shaft on

the thrust surfaces.

6. Check the crankshaft thrust bearing

side clearance with a feeler gauge at the

front side of the center bearing on both

upper and lower thrust faces. Specified

side clearance is .004 to .008 inch.

1-51

While making this check, be sure the

crankshaft is held against the rear thrust
face of the bearing to show total clearance
at front side.

7. Install the connecting rod bearings

and caps. Refer to page 1-35.

8. Install the hydraulic oil pump (if soequipped).

11. Install the flY1Wheel and secure

with the cap screws. Tighten the cap

screws to 45 ft. lbs. torque.

12. Install the oil pan.

9. Install ~ front and rear crank-

shaft oil seals in their retainers.

10. Install the rear oil seal retainer.

13. Install the front cover and the fan

drive pulley. Refer to page 1-40.

14. Install the engine in the tractor.

Refer to page 1-12.

1-52

The engine lubricating oil is taken from

the oil pan through a screened intake pipe

up to the oil pump, where it is discharged
into a gallery running lengthwise in the
left hand side of the crankcase casting.

From this gallery, drilled holes lead off

to the valve tappets, camshaft and cr~­shaft main bearings.

Drillings in the crankshaft convey oil
from the main bearings to each connect-

ing rod bearing. Oil thrown from the
connecting rods and main bearings lubri­cates the pistons, piston pins, and cylin­der walls.

Another drilled hole from the main

gallery supplies oil to the timing idler
gear stud, and the pressure reg11lator

The pressure regulator valve and

spring is retained by a hex-head plug on
the right side of the crankcase near the
timing gear end. Oil bypassed by the

regulator valve is returned to the oil pan.
A drilled hole from the main gallery also

delivers oil to the oil filter. Flow of oil

through the filter element is metered by
the outlet orifice in the cover retaining

bolt. Cleaned and filtered oil is re-

turned to the oil pan from the drilled

retaining stud.

The timing gears and governor are

lubricated by oil thrown from the front

bearings of the camshaft and crankshaft,

and from the idler gear stud.

Oil Pump

The gear type oil pump is located at the

rear end of the camshaft outside the
crankcase behind the flywheel. The pump
draws oil through a drilling in the crank-

case and the intake pipe from the oil in-

take screen. Clean this screen each time
the oil pan is removed. The connection
between the oil intake pipe and the crank-

case must be air tight.
A liS-inch pipe plug, located at the rear

left side of the crankcase near the top of

the flywheel housing, gives access to the

pump for priming. This priming should

only be necessary when the pump has been
assembled dry or after long periods of
storage, where the pump may have
drained completely.

The oil pressure indicator shows whether
the oil pump is working, when the system

is correctly filled. At idle speed or above

the indicator needle should register. If

the needle does not register stop the en-

gine and determine the reason.

valve.

1-54

Pressure Regulator Valve

Since the normal output of the oil pump is

much greater than the normal require­ment of the engine lubricating system,
and all the oil cannot escape through the
engine bearing clearances and metered

passages, a spring-loaded reguaator

valve is employed to release the excess

oil. This valve maintains an operating
oil pressure of 30 -35 lbs. at 1800 rpm.

The piston-type pressure regulator valve
and spring is located behind the hex-head

retaining plug on the right side of the

crankcase, near the timing gear end.

The valve should slide freely in the

crankcase bore and the spring should be

straight so that the valve will not be

cocked in the bore or on its seat.

The free length of the valve spring will

give some indication of its condition.

However, the best test to determine the
spring' s tension is to load it with the
weight specified, and measure its length

at that load. If this tension test is found
below specifications the spring should be
replaced or low oil pressure will con-

tinue.

During a complete engine overhaul, while
the engine is completely disassembled,

all oil passages should be cleaned, using
brass rifle brushes. Also, if crankshaft

or connecting rod bearings have failed
due to abrasives in the lubricating oil,
the engine must be completely disassem­bled and thoroughly cleaned. Clean all

lubricating oil passages, using rifle

brushes and compressed air. Clean and

inspect the oil pump and pressure

regulator assembly and service them as

required.

CD

1. Plug

2. Spring

3. Valve

Removal and Disassembly

If oil pressure is not within specifica-

CD

fESM-3278

tions, the oil filter regulator valve, in­take pipe with screen, and the pump may
be disassembled as follows:

1. Remove filter element and clean

filter case. If filter case is exceptionally

sludgy, install bolt without cover and

flush thoroughly.

2. Remove hex-head regulator valve
retaining plug and remove the spring
and valve.

3. Remove the crankcase oil pan.

Remove the oil intake pipe and screen.

1-55

FfSM-3614

4. Remove the engine. Refer to

page 1-10.

Remove the flywheel.

6. Remove the oil pump body and

pump gears.

nspection and Servicing

1. Clean regulator valve assembly

and valve bore.

2. Check condition and tension of
regulator valve spring. If spring is bent
or rusted or the tension is not within
specifications it should be replaced.

3. Check regulator valve to make sure

it slides freely in its bore.

4. Thoroughly clean oil intake pipe

and screen. Check screen and connec-

tions for damage.

5. Check oil pump drive gear shaft

and key for wear or damage.

6. Check pump gears for wear or

damage.

7 .Check pump body for wear ordamage.

Clean crankcase breather.

9. Clean oil passages in crankcase

with a round, bristle type or brass riflebrush.

5.

I

8.

1-56

1. Install new filter element along

with cover and drain plug.

2. Install regulator valve, spring and

retainer, using new retainer gasket.

3. Install oil intake pipe and screen.

4. Install crankcase pan, using newgasket.

5. Install oil pump gears.

6. Install pump body, using new

gasket.

7. Install the flywheel and secure

with the four cap screws. Tighten cap

screws to 45"ft. lbs. torque.

8. Install the engine in the tractor.

Refer to page 1-12.

9. Fill crankcase with proper amount

of specified oil.

10. Prime oil pump, start engine and

check oil pressure.

11. Recheck crankcase oil level.

1-57

COOLING SYSTEM

Water or an antifreeze solution circulates

through the engine block and radiator by
thermosiphon action. As the water in the

engine becomes heated, it moves upward
and enters the radiator at the top. The
water is cooled by the air blast drawn
between the radiator tubes by the fan.
The cooled water moves to the bottom of

the radiator and back into the engine
block to replace the heated water passing

GSS-1411 tRev.No.1)

out at the top. This creates a circulation
in the system.

The radiator is the flat-tube type and is

enclosed in a grill. The cooling fan is
equipped with a shroud which greatly
increases its efficiency. A drain plug,
located in the bottom of the steering gear

housing base, permits the entire cooling

system to be easily emptied.

A CAUTION: Work should not be

~a done on the cooling system

while the system is hot or near

operating temperature.

NOTE: Effective with tractor chassis

serial number U248125 and above is the

new Rota-Safe pressure cap. The new

pressure cap has a pressure relief twist

top for safer removal when the cooling

system is hot.

Printed in United States of America

1-58

Removal of Radiator Assembly

1. Remove the pipe plug located in the

bottom of the steering gear housing and

drain the coolant.

2. Disconnect the ground wire from

the battery and the wires to the headlights.

3. Shut off fuel at the fuel strainer and
disconnect the fuel line. Remove the head­lights and the hood and fuel tank assem-

bly.

4. Remove the radiatpr grille ass em-

bly.

5. Disconnect the top hose from the

radiator elbow (1).

6. Remove the screws securing the

fan housing (2) to the radiator.

7. Move the fan housing (2) out of the

way, and remove the cap screws securing
the radiator (5) to the steering gear hous-

ing (4).

8. Remove the radiator side channels

(3) and remove the radiator assembly

from the tractor.

I nspection and Repair

During servicing or repair procedures,

inspection of parts and assemblies in-

volved is always an important responsi-

bility of the serviceman. Generally, in-

spection is performed after disassembly
has been completed, however, in many
cases, time can be saved by inspecting
parts when they are being removed.

Be sure to check the following items and

perform the servicing or repair that is

indicated.

GSS-1411 (Rev- No.1)

1. Inspect the radiator for accumula-

tion of rust or leaks and flush out pas­sages in the engine.

2. Check all hoses and if badly

cracked, or dry and hard, they should bereplaced.

3. Overheating is often caused by bent

or clogged radiator fins. If the spaces

between the fins are clogged, clean them

out with compressed air or water. Avoid

poking into the spaces with any hard

object.

Printed in United States of America

1-59

4. If fins are bent, they should be
straightened, but be careful not to dam­age the tubes or break the bond between
the fins and the tubes. Check carefully

for possible leaks after completing this
work and before completely reassembling

the radiator.

5. Inspect radiator passages for clog-

ging. If this condition is found, the pas-

Installation of Radiator Assembly

sages should be cleaned at a qualified

radiator service station.

CAUTION: Never use chemical mix-

tures to stop radiator leaks except as a

temporary or emergency procedure. It
should then be followed by correct serv­icing at an early date.

1. Using a new gasket, install the

radiator assembly on the steering gear

housing.

side channels. Tighten the cap screws
to 20 ft. lbs. torque.

3. Install the fan housing on theradiator.

4. Connect the water outlet hose.

Cooling Fan Service

5. Install the radiator grille assembly.

6. Install the hood and fuel tank and

the headlights. Connect the fuel line to
the fuel strainer.2. Install the hold down plates and the

7. Connect the wires to the headlights

and the ground wire to the battery.

8. Install the pipe plug in the bottom
of the steering gear housing, and fill the
radiator with coolant.

Removal and Disassembly

1. Remove the headlights and the hood

and fuel tank.

GSS-1411 (Rev. No.1)

2. Loosen the tension on the generator

drive belt and move the belt out of the
pulleys.

3. Disconnect and remove the water

outlet elbow and hose.

4. Remove the air cleaner assembly

from the engine.

5. Remove the screws securing the

fan housing to the radiator.

Printed in United States of America

1-60

6. Loosen the nut securing the
spindle to the crankcase front cover, and
remove the cooling fan assembly from

the tractor.

7. Remove the fan blade from the

fan assembly.

8. Remove the fan bearing cap (6).

9. Remove the lock nut (4) and the
impeller (5) from the spindle. Note the
position of the impeller for proper re-

assembly.

10. Remove the bearing (3) from the

spindle and hub.

11. Remove the spindle (2) from the

hub assembly (1).

I nspection and Repair

1. Check the spindle, bearing and hub

for wear or side play between them.

NOTE: The assembled fan hub assem-

bly should have a ~ amount of end

play on the spindle and should turn freely
without noticeable drag.

2. Check the fan drive pulley which is

a press fit on the engine crankshaft. If

there is looseness, check for wear of the

key and in the hub. Replace parts as

necessary to obtain a tight fit.

3. Inspect the fan drive V-belt and re­place it if it is badly oil soaked, if it
tries to run on its side in the pulleys, if

it is badly cracked beyond the cover

layer, or if its sides are so worn that it

will not drive the fan at the correct speed.

GSS-1411 (Rev. No.1)

Printed in United States of America

1-61

Reassembly and Installation

1. Using a new fan hub gasket (3), in-stall
the spindle (1) and bearing assembly

(4) in the hub assembly (2).

2. Install the impeller (8) on the
spindle (1) and then install the lock nut
and tighten to 20 ft. lbs. torque.

3. Install the fan bearing cap (7) using

a new gasket(5).

4. Install the fan blade (6) and secure

with the cap screws and double nuts (9).

5. Install the fan assembly and belts
on the crankcase front cover. Do not
tighten the belts at this time.

6. Install the screws securing the fan

housing to the radiator.

7. Install the air cleaner on theengine.

8. Install and connect the water outlet

elbow and hose.

9. Adjust the tension on the fan driveand
generator belts to allow 1/2 to 3/4

inch slack on the fan drive belt and 1/4

inch slack on the generator belt as shown.

GSS-1411 (Rev. No.1)

Printed in United States of America

1-62

10. Turn the fan hub so the oil re-

tainer screw is at a right, horizontal

position. Remove the screw and fill the

hub with lubricant. (Refer to Operator's

Manual.)

11. Turn the filler hole to the bottom

position and let excess oil drain out.

This filler hole has a stud on the

inside which controls the level of oil tobe

held in the hub. When oil stops running

out, replace the retaining screw.

12. Install the hood and fuel tank. Con­nect the fuel line to the fuel strainer.
Install and connect the headlights.

If a specific problem and remedy is not
covered herein, proceed to isolate the

system in which the problem occurs and
then locate the defective component. The
greater the number of symptoms of prob-

lems that can be evaluated the easier will

be the isolation of the defect.

Much can be learned about the condition

of an engine if a good visual inspection is
performed before the actual cleaning op­erations are begun. Many engine parts

give external evidence of some failure or

defect which can be looked for when the
engine is later disassembled. For ex­ample, a heavy accumulation of oil or
grease at some spot might indicate a leak-

ing seal or gasket; or, excessive rust and

other corrosion at another place might

well mean leaks in the cooling system.

SHOOTING

If an engine can be operated, unusual

noises also help determine what defects
to look for. However, before engine dis-

assembly is started, the outer surface

should always be given a thorough clean­ing. Methods used will depend on the
facilities available or other local condi­tions. The dry steam method is recom­mended since this is both fast and effec­tive. After steam cleaning, the engine
should be wiped dry with a clean cloth to
minimize possible rusting. After clean­ing, the exterior of the engine should

once more be inspected carefully and a
note made of any parts such as brackets,

covers, bolts, etc., that are bent, broken,rusted

or missing completely. The crank-

case or cylinder block should be checked

for evidence of freezing aroun~ core plugs
or for actual breaks in the water jacket.

TROUBLE

1-63

1. Cranldng motor inoperative or

defective.

Engine Will Not Turn Over

Battery faulty.

Replace Battery.

Cables and terminals faulty. Inspect ground cable and battery-to-

starting switch cable for any faults

which may cause shorting; also in-

spect for incorrect connections.

Replace cables if necessary.

Starting switch defective. Replace starting switch.

5. Internal seizure. Hand crank engine with spark plugs re-

moved and clutch disengaged. If engine
does not turn easily, internal damage is

indicated.

Engine TW'ns But Will Not Start

1. Fuel system faulty

No fuel in tank.

(a)

Fuel strainer bowl screen

(b)

clogged Water in gasoline.

Fill tank with fuel.

Clean bowl and screen.

2. Battery charge low and does not turn

Replace.

2.

3.

4.

3.

(c)

(d) No gasoline at carburetor.

engine fast enough.

Ignition system faulty.

(a) Broken distributor rotor. (b) Moisture in the distributor.

Drain gasoline tank, gasoline strainer and

carburetor. Refill with clean gasoline.

Clean fuel line from tank to carburetor.
Clean fuel inlet screen in carburetor.

Check for clogged vent holes in fuel tankcap.

Charge or replace battery.

Replace rotor.

Remove cap and rotor and dry off. Use
compressed air to remove moisture fromdistributor.

1-64

Engine Turns But Will Not Start -Continued

Ignition system faulty -Continued

(c) Condenser shorted or open.

(d) Broken distributor cap. (e) Excessively pitted distributor

cap contact terminals.

Points not properly adjusted. ...

(f)

(g) Short or open circuit in

distributor.

(h) Ignition circuit broken.

(i) Wet or fouled spark plugs.

Cracked or broken spark plug

(j)

insulators. '.

condenser.

cap.

Clean contact terminals with fine sand-

paper. Blow all sand out of cap before

reinstalling.
Readjust points. Refer to "Tune-Up",

page 1-74.

Correct or replace.

Check cable from distributor cap-to-

ignition coil and check spark plugs for

correct wiring or loose connections.

Remove spark plugs, wipe off moisture
and dry plugs. Remove carbon. Reset
plug gap; refer to "Tune-Up", page 1-74.

Replace spark plugs.

(k) Ignition switch inoperative.

Carburetor choked too much.

Place a jumper wire across the two
ignition switch terminals on the back of

the switch. Attempt to start the engine.

If engine starts, the switch is inoperative

and must be replaced.

Open the choke. Wait a few minutesbefore

attempting again to start engine.

Air intake restricted or exhaust

clogged. Service the air cleaner and clean exhaust

system.

3.

Replace

Replace

4.

5.

1-65

Missing and Backfiring But Fails to Start

1. Water in gasoline.

Air leaks around intake manifold. ...

Improper firing order

Distributor not correctly timed to

engine.

Moisture in the distributor.

Distributor cap shorting out.

Missing or Cutting Out at High Speed

1. Distributor Breaker Plate not
grounded properly.

Drain fuel tank, fuel bowl and carburetor.Refill

with clean gasoline.

Tighten manifold stud nuts. Replace
gasket if necessary .

Check spark plug cables for correct in­stallation at spark plugs and distributor

cap.

Check and adjust timing. Refer to
"Tune- Up", page 1-74.

cap and rotor and dry thoroughly.

Check for loose contact terminals or

dirt in cracked cap.

Check ground lead wire and screws.

Primary lead not tightened or

partially broken.

Weak point spring tension.

Spark plugs faulty.

Point gap incorrect.

Low voltage to spark plugs caused

by defective coil.

Carburetor

(a) float level set too low. (b) Dirt in main jet.

(c) Restriction in filter.

Check primary lead wire and screws.

Adjust point spring tension or replace

points.

Check plug gap. Refer to "Tune-Up",

page 1- 74 for correct gap. Replaceplugs

if necessary.

Readjust point gap. Refer to "Tune-Up",

page 1-74.

Replace coil.

Check float level. Reset if necessary.
Clean out main jet. Replace if necessary.
Clean out fuel inlet filter in carburetor.

2.

3.

4.

Remove

5.

6.

2.

3.

4.

5.

6.

7.

1-66

8. Poor compression:

Missing or Cutting Out at High Speed -Continued

(a) Head gasket leaks. (b) Burned valves.

Worn piston rings.

(c)

Distributor

Point gap incorrect.

Spark oovanced too far.

Fouled spark plugs.

Carburetor
(a) Main metering system too

lean.

head gasket.

Grind valves.

Replace piston rings.

Pinging -Detonation

Readjust point gap. Refer to "Tune-Up",

page 1-74.

Check and adjust timing. Refer to
"Tune-Up", page 1-74.

Clean plugs and reset the gap. Refer to

"Tune-Up", page 1-74.

Adjust carburetor. Refer to "Fuel
System ", Section 2.

Float level set too low.

(b)

Check float level and reset if necessary.

Cylinder head not bolted down

tight. Torque cylinder head bolts. Refer to

page 1-14 for tightening sequence.

Does Not Operate Smoothly

Pitted distributor points.

Clean and readjust points or replacepoints.Replace.

Cracked distributor cap.
Wom or bent distributor shaft.
Worn breaker plate hub.

Replace.

Replace breaker plate assenibly.

Worn distributor carn.
Improper point spring tension.

Adjust point spring tension or replace

points.

Replace

Excessive

1.

2.

3.

Engine

1.

2.

3.

4.

Replace.5.

6.

1-67

1. Distributor:

Engine Does Not Develop Full Power

Point gap incorrect.

(b) Ignition timing incorrect.

Low voltage to spark plugs

caused by defective coil.

Fouled spark plugs.

Carburetor:

float level set too low.

(b) Choke plates partially

restricted.

(c) Restricted throttle linkage.

Insufficient air to engine.

Readjust point gap. Refer to "Tune-Up",

page 1-74.

Check and adjust timing. Refer to
"Tune-Up", page 1-74.

Replace coil.

Clean plugs and reset the gap. Refer to

"Tune-Up", page 1-74.

Check float level. Reset if necessary.

Reposition choke controllinkage.

Repair or replace.

Service the air cleaner.

2.

3.

4.

5.

6.

7.

9.

See

Late valve timing.

Air leaks around intake

manifold.

8. Exhaust restricted.

Lack of compression.

10. Governor worn out or out of
adjustment.

Check and adjust timing. Refer to
"Specifications."

Tighten manifold or install new gasket
if necessary.

nemove restriction.

"Lack of Compression" in thischart.

Refer to governor section of "Fuel
System", Section 2.

1-68

1. Low lubricating oil level.

Add sufficient oil to bring level up to

specified mark on level gauge.

2. Cloggedoilfilter

Oil leaks.

Engine oil pressure indicator or

line defective.

Worn main, connecting rod or

camshaft bearings.

6. Dirt in oil filter relief valve or
relief valve spring broken.

7.

Oilpumpworn
Oil diluted or not as specified.

Change filter element.

See "Excessive Lubricating Oil Con­sumption" in this chart.

Replace.

Clean valve or replace spring.

Repair or replace.
Change oil regularly using correct

grade specified in Operator's Manual.

Lack of Compression

Valves sticking.

Worn pistons, rings and cylinder

walls.

Defective cylinder head gasket.

Broken valve f.pring

1. Engine overload.

Incorrect grade lubricating oil.

Clean valve guides and stems. Grindvalves

if needed.

Replace pistons, rings and cylinder

sleeves.

Replace.

Smoky Exhaust

Reduce load.

Use grade of oil specified in Operator's

Manual.

1-69

3.

4.

Replace.5.

8.

1.

2.

3.

Replace.4.

2.

Smoky Exhaust -Continued

3. Worn valve guides, valve stems,
pistons and sticky or worn oil

control rings.

Repair or replace.

4. Distributor not properly timed.

5. Choke not fully open.

Excessive Lubricating Oil Consumption

Oil leaks

Worn valve guides, piston rings,

pistons and clogged oil control

rings.

3. Incorrect grade of lubricating oil. ...

Over-heated engine.

Check and adjust timing. Refer to

"Tune-Up", page 1-74.

Open choke fully.

Check and service where necessary;
valve covers, tappet cover plate, crank­case front cover, oil seals at front and

rear of crankshaft, oil pan plug, gasket,

oil filter and oil pressure indicator tube.

Replace worn parts.

Use grade of lubricating oil specified in
Operator's Manual.

Refer to "Engine Overheats" in this chart.

1.

2.

4.

5.

1.

(a)

2.

3.

1-70

Excessive oil poured into crankcase. .

Excessive Fuel Qonsumption

Distributor:

Point gap incorrect.

(b) Ignition timing incorrect.

Low voltage to spark plugs caused

by defective coil.

Worn or fouled spark plugs.

Drain oil. Add amount specified in

Operator's Manual.

Readjust point gap. Refer to "Tune-Up",

page 1-74.

Check and adjust timing. Refer t9

"Tune-Up", page 1-74.

Replace coil.

Clean plugs and reset the gap. Refer to

"Tune-Up", page 1-74 for correct plug

gap setting.

Carburetor:

Excessive Fuel Consumption -Continued

(a)

Leaking needle or seat. Repair or replace.

(b)

level set too high.

(c) Choke plate not fully open.

Check float level and reset if necessary.

Reposition choke control linkage.

Restriction in air cleaner. Service the air cleaner.

Noises

Loose piston pin. A sharp rap at
idling speed. The pin at fault can

be found by short circuiting the

spark plugs, one at a time, until

the noise stops

A flat slap, when advancing engine

speed under load, indicates a

loose piston.

A metallic knock when idling and

retarding engine speed, but disappears

under load indicates worn or loose

connecting rod bearings. The bear­ing at fault can be located by short

circuiting the spark plugs one at a
time. The noise will disappear when
the cylinder with the defective bear-

ing is short circuited.

Repair or replace.

Replace piston.

worn bearings.

1. Lo.w oil pressure.
Lackofoil

Engine runs too hot.

4.

Float

5.

Engine

1.

2.

Replace

3.

2.

3.

1-71

Bearing Failure

Refer to problem "Loss of Oil Pressure."

Maintain proper oil level. Check for

leaks.

Keep engine at normal operatingtemperature.

Bearing Failure -Continued

Loose bearings.

Improper lubricating oil.

Foreign materials entering engine. ...

7. Oil lines clogg~d
Connecting ro~ bent.

9. Cr~hafto~of alignment.

1. Valve springs weak or broken.
Gummy deposits from inferior fuel

or oil.

Install new bearings.

Use a suitable oil of non-corrosive type,

correct grade and viscosity.

Use clean oil containers when filling
engine with oil and see that all gaskets

on the engine are in good condition.

Clean all oil passages.

Align or install new connecting rod.

Straighten or install new shaft.

Valves Sticking

Install new springs.

Clean and use proper fuel or oil.

Valve stems scored or carboned.

Insufficient clearance between valve
stem and guide.

Overheating Due to Restricted Air Flow

1. Bent fan blades.

2. Trash between radiator fins.

Bent radiator fins.
Fan housing damaged or missing.

Install new valves if necessary.

Ream guides for proper clearance.

Straighten and correct pitch of fan blades.

Clean out thoroughly between radiator
fins. Use compressed air.

Straighten bent fins.

Repair or install new fan housing.

1-72

4.

5.

6.

8.

2.

3.

Clean.

4.

3.

4.

Overheating Due to Poor Condition

1. Restrictions in radiator core or
engine water jacket.

Drain system. Disconnect hoses and
reverse flush the radiator and block.

Low coolant level.

Pressure cap loose -coolant

escaping.

Fan belt slipping or loose.

Overheating Due to External Leakage

1. Defective hoses or connections.

2. Radiator leaks.

Damaged gaskets.

Fill cooling system to proper level.

Check for leaks.

Tighten pressure cap.

Tighten if loose. Replace belt if

greasy, worn or damaged.

Replace defective hoses. Check clamps

for fatigue and replace as re~red.

Remove radiator. Test for leaks and

solder.

Check for leaks around water inlet and
outlet elbows and cylinder head. Replace

defective gaskets.

Cracked or warped cylinder head.

5. Cracked cylinder block.

Defective water inlet or outlet elbow. ..

1. Warped cylinder head.

2. Blown cylinder head gasket.

2.

3.

4.

3.

4.

6.

Replace cylinder head and gasket.
Replace cylinder block.

Replace,

Overheating Due to Internal Leakage

Replace cylinder head and gasket.
Replace gasket. (Check crankcase oil

for presence of water.)

1-73

Overheating Due to Internal Leakage -Continued

Cylinder head cap screws not

properly torqued.

Torque head cap screws. Refer to

page 1-14.

4. Cracked cylinder wall.

TUN E-UP

The following steps outline the operations
which should be followed in an enginetune-up.

These steps point out thevarious

parts of the engine to be checked,

cleaned, timed or repaired, as needed.

For detailed information on the repair

and adjustment of the components of the

respective Systems, Fuel and Electrical

refer to "Fuel System" Section 2 and
"Electrical System" Section 9.

Check the throttle control.

cylinder block.

2. Check the clearance on intake and

exhaust valves and make adjustments ifnecessary.

(Refer to "Valve ClearanceAdjustments",

page 1-15.)

3. Check the air cleaner and connec-

tions for possible leaks. Refer to the

Operator's Manual.

4. Replace the lubricating oil filter

element and clean the filter case assem­bly thoroughly.

(a) Check the operation of the

control.

(b) Check the operation of thesprings

(c) Check the rpm of the engine,

using a tachometer.

3.

Replace

1.

on the governor control rod.

5. Remove the fuel strainer bowl and

clean thoroughly.

6. Flush the radiator with clean

water, then drain and refill with soft

water if available, or anti-freeze solu­tion in cold weather.

1-74

7. Check the fan belt for wear and cor-

rect tension. Replace if necessary.

8. Check the distributor points, cap and

condenser. Replace necessary parts and

reset point gap to .020 inch.

9. Check the spark plugs. Replace
broken plugs and clean and reset all plugs
to be reinstalled. Set gap at .023 inch.

12. Check all switches.

13. Remove and clean the carburetor

inlet screen.

14. Remove the fuel bowl and check the

float level. Adjust if necessary.

15. Check the float valve assembly for

leakage.

10. Check the ig11ition coil and the
primary wires and be sure the connections
are clean and tight. A few broken wire

strands on an otherwise sound connection

will still result in difficult starting and

in1proper engjne perforrnance.

11. Check all electrical connections in

both the high and low tension circuits of

the ignition system.

16. Inspect the generator and cranldng

motor commutators and clean.

17. Check the ignition timing and cor-

rect if necessary. Set t[ming at 160 before
T .D.C. at high idle.

18. Check the compression pressures.

Refer to !'Specifications".

1-75