1968 DATSUN 510 ignition

ENGINE
AND
IGNITION
TUNE
UP
21

many
types
of
test

eqUipment
and

may
be
used

as
a

gUide
If
the
manufacturer

s

mstructioQs
are

not
aVailable
Connections
shown
in

Figure
1

are
as
follows

1
Voltmeter

a
PosItive
lead
to
resistor
side
of
COli

b

Negative
1
ead
to

ground

2

Tlmmg
Light

a
PosItive
lead
to

posItive
battery
termmal

b

Tngger
lead
to
number
1

spark
plug

c

Negative
lead
to

ground

3
Tachometer

a
PosItive

lead
to
dlstnbutor
Side
of
coil

b

Negative
lead
to

ground

4
Dwell
Meter

a

PosItive
lead
to
dlstnbutor
Side
of
COlI

b

Negative
lead
to

ground

BAlTERY
INSPECTION
AND
SERVICE

1
Check
the
level
of
the

electrolyte
m

battery

cells
If

necessary
replemsh
with
distilled
water

Do
not
overfill

2

Measure
the

speCific
gravity
of
the

battery

electrolyte
Refer
to
the

followmg
table
2
Use
the

proper
size
socket
and
wrench
to

remove

spark
plugs
from
the

cyhnder
head

Make
certam
that
the

gaskets
are
removed
from

the

spark
plug
holes

3

Wipe
off
the
msulator
With
a
clean

rag
to

remove

grease
and
dirt

4

Carefully

mspect
the
msulator
and

body
of

each

plug
for

signs
of

cracks
or

chips

Replace

If

faulty

5

Inspect
spark
plug
threads
and
electrodes
for

damage
or
excessive
wear

Replace
as

requrred

Figure
2
shows
the

cond1t
J
on
of

normal
and
de

fectIVe

spark
plugs
along
with

an

explanation

of
the

causes
of

the
abnormal
conditions

6
If
the

spark
plugs
are
still
serviceable
clean

them

thoroughly
With
a

stiff
brush
or

preferably

With
a
sand

blasting
type
of
cleaner

7
File
the

center
electrode

so
that

It
has

a
fiat

surface

8
File
the
surfaces
of
the
outer
electrode

so
that

all
surfaces

are
fiat
and
smooth

9

Usmg
a
feeler

gauge
adjust
clearance
be

tween
the
electrodes
to
0
031
to
0
035
m
0
8

to
0
9mm
as
shown
m

Figure
3

Full

Charge
Value

CD
68

degrees
F

PermiSSIble
Value
20

degrees
C
3

Frigid
chmates

Tropical
chmates

Other
climates
Over
1
22

Over
118

Over
1
20
128

123

126

3
Clean

top
of

battery
and
termmals
With
a

solutIOn
of

bakmg
soda
and
water
Rmse
off
and

dry
thoroughly
Top
of

battery
must
be
clean
to

prevent
current

leakage
between
termmal
and

from

pOSitive
termmal
to
hold
down

clamp
Pro

longed
accumulatIOn
of
aCid
and
dirt
on

top
of

battery
may
cause

blIstenng
of
the
matenal
cov

enng
on
the
connector

straps
and
detenoration

of
the

straps
themselves

4

Tighten
the
cable

connectors
to
the
termmal

securely

5
Coat
the
termmals

lIghtly
With

petrolatum
to

protect
them
from
corrosion

SPARK
PLUGS
INSPECTION

AND
SERVICE

1
Remove

spark
plug
WIres
Mark
them
to
fi

sure
correct

replacement
J

J

I

I

j

j

10
Remstall

spark
plugs
Make
certam
to
use

a
new

gasket
for
each

plug
Use
a

torque
wrench

to

tighten
spark
plugs
from
11
0
to
150
ft
lb

1
5
to
2
0

kg
m

11
Remstall
WIres

DISTRIBUTOR
INSPECTION

AND
SERVICE

Dependmg
on
the
model

year
velucles
have

a

smgle
pomt
or
a
dual

pomt
dlstnbutor

system

ENGINE
AND
IGNITION
TUNE
UP
23

CD
ADJUSTING
SCREWS
FOR
THE
POSITION

OF

RETARDED
BREAKER
POINT

r

A
O
S

8

6

C

0

18

2
6
10
14

contact

pomt
assembly
from
the
dIStnbutor
and

clean
or

replace
the

pomts
Use
a

pomt
file
to

clean
the
contacts
Do
not

attempt
to
remove
all

roughness
Apply
a
trace
of

beanng
lubncant

to
the
breaker
cam

5
Once
the

pomts
have
been
cleaned
or
re

placed
mstall
the

assembly
m

the
dlstnbutor

Make
certam
to
reconnect
wires

6

Adjust
the

pomt
gap
Figure
S
With
the
use

of
a
screwdnver
and

gap
gauge
Make
certaIn

the

rubbmg
arm
on
the
contact

assembly
IS
rest

mg
on
the

hIgh
pomt
of
the
carn
Pomt

gap

should
be

adjusted
to
0
0177

through
00217

m

0
45
to
0
55mm

CD

7
Check
condenser

capacItance
for

a

readmg
of

o
22

through
0
24
mIcrofarads

Replace
If
de

fectIve
As
a
matter
of

good

practIce
the
con

r
denser
should
be

replaced
whenever
the

pomts

are

replaced

8

Inspect
the
InSulatIon
on
all
WIres
WIthIn
the

dIStributor

Replace
If
defectIve

9

Inspect
the
WIre
towers

atop
the
dIStnbutor

cap
for

SignS
of
dIrt
or
corrosIOn
A

pencIl
wIth

fine

emery
cloth

wrapped
around
the

erasl
e
end

can
be
used
to
clean
and
burnISh
the
metal
sur

faces
Make
certam
to
blowout

any
dust

10

Replace
the
rotor

md
the

cap
on
the
dIs

tnbutor
and
secure
the
two
hold
down

clamps

FI

ly
msert

IgrntIon
WIres
mto

proper
towers

ill

cap

IGNITION
TIMING

IgmtIon
tIDlIDg
is

adjusted
with
the

engine

runnmg
Use
a

strobOSCOpIC
timing
hght
and

pro

ceed
as
follows

1
Make
certam
that

spl
l
k

plug
gaps
and
dIs

tnbutor
contact

pomts
are

accurately
set

2
DISconnect
the
vacuum
hne
from
the
carbu

retor
at
the
dIstrIbutor

Plug
the
end
of
the

vacuum
hne
wIth

tape
or
a
wooden

stopper

3
Hook

up
the

trmmg
light
per
mstructIons

4
Hook

up
tachometer

per
mstructions

5
The

tImmg
marles
are
located
on
the
front

edge
of
the
crankshaft

pulley
The

grooves
are

graduated
m
5

degree
mcrements
The

top
dead

center
mark
S
located
to
the
extreme
left
hand

sIde
of
the

engme
as
vIewed
from
the
front
A

statIOnary
pomter
S
connected
to
the

cylinder

P

r
OVll

t
ate

I
l
h
l
JlA

ye
I
o

ctg
fI

O
0

I
d

1e
d
c

Ji
uo
JJ

cb
c
s
rlr
I

l
4

c
1
2

24

CHAPTER
FOUR

block

and
should
be
used
as
the
reference

point

m

II
1akmg

adjustments

6
With
a

piece
of
white
chalk
mark

a
hne
down

the
center
of
the

pomter
and
mark
the

timing

groove
on
the
crankshaft

pulley
which

IS
to
be

used
m

tImmg
the

engine
SpecIficatIon
for
tun

ing
reqUIres
trlhmg
at
10

degrees
before

top

dead
center
wluch
would
be
the

fourth
mark

from
the
left
end
of
the

row
of
marks

7
Loosen
the
hold
down
bolt
at
the
base
of
the

dlstnbutor

8
Locate
the
slow

speed
1
Ile

adjustIng
screw
on

the
carburetor

so
that
Ile

speed
can
be

adjusted

whIle

runnmg
Also
locate
throttle

adJustmg

screw

9
Start

engme
and

adjust
speed
With
the

adJust

ing
screws
to
the

readmgs
below

Smgle
pomt
dIStributor
600

rpm

Dual

pomt
trlbutor
700

rpm

10
Alternate

adjustment
of
the
two
screws

untIl
the
smoothest
Idle
at
the

proper
speed
IS

achieved

11
Pomt
the

tlIrung
lIght
at
the

stationary

pomter
When
the

lIght
flashes
the

timmg
mark

n
the
crankshaft

pulley
should

hne

up
With
the

mark
on
the

stationary
pomter
If
It
does
not

exactly
Ime

up
rotate

the
dlstnbutor

gradually

untIl
the
marks

align
mdlcatlng
correct

timmg

12
Shut
off
the

engme
remove
the

tmung
lIght

and
tachometer

tighten
the
hold
down
bolt
on

the
dlStnbutor
and
connect
the
vacuum
advance

hne
to
the
tli
tnbutor

IGNITION
TIMING

IDLE

SPEED
IDLE

MIXTURE

DUAL
POINT
DISTRIBUTOR

ONLY

The

followmg
applies
to
velucles
With
dual

pomt
distributor
and
an
exhaust
emission
con

trol
deVice
If
these

procedures
are
followed

ha
ul
exhaust

emisSion
should
be
below
the

maximum
allowable
level

1
Locate
the
Idle

and
throttle

adJustmg
screws

on
the
carburetor

2
Warm

up
the

engine
thoroughly

3
Connect

tachometer
and

tmung
light

4
Set
the

Id
le
speed
at
700

rpm
With
the
Idle

adjust
screw
5

Adjust

IgnltJ
on

tuning
at
10

degrees
before

top
dead

center

6
Increase
the

speed
of
the

engme
to
2
000

rpm

With
the
accelerator

or
throttle

hnkage
and
hold

for
about

15
seconds

7
Return
to
Idle
for
one
mmute

8
Set
the

engme
to
best
Idle
at
750

rpm
770

rpm
for
automatJ
c
transIDlsslOn
With
the
Idle

and
throttle

adJustmg
screws

9
Re

uce

engme
speed
at
700

rpm
720

rpm

for

automatic
transmission

by
turnmg
the
Idle

adJustmg
screw
clockWise
for
a
leaner
IlliXture

10
Connect
a
wife
lead
between
the
advance

ami
retard
Side
tenrunals
See

Figure
4

Speed

should

drop
from
100
to
150

rpm

11
Check

IgIl1tIon
tmung
With

tImmg
light
It

should
now
be
at

top
d
ad
center

12
If
the

tlmmg
IS

nSJt
correct

stop
the

engme

and

adjust
the
retarded
breaker

pomt

13
Start
the

engme
and
reclieck
ili

tmung
If

l

incorrect
reset
the
retarded
breaker

pomt
until

it
IS
correct

Repeat
s
nece

s

14
Disconnect
the
wife

bet
reen
the
advance

and
retard
termmals

15
Recheck

tmung
It
should

be
10

degrees

before

top
dead

center

16
If
mcorrect

repeat
the
above

procedures

un
tIl

satIsfactory

17

T
he
Idle

speed
of
automatic
transnllsslOn

vehicles
should

be
about
575

rpm
With
the

gear

j

selector

m
the

dhve

poSltlon
c

t

DWELL
ANGLE
SETIING

1
Connect

the
dwell

angle
meter

2

PLoJust
dwell

angle
to
49

to
55

degrees

OMPRESSION
TEST

I

A

compressIOn
test
IS

performed
to
check
for

worn

piston
nngs
or
to
detect
the

cause
of

a

low

speed
miss
Before

undertaking
the

test

el
llmate
the

pOSSibility
of

sticky
valves

by
usmg

one
of
the

oil
additives

deSigned
for
the

purpose

With
valves
free
test

compressIOn
as

follows

1
Run
the

engme
for
15
to
20
mmutes
untIl

normal

operating

temperatures
are
obtained

2
Shut
off

engme
remove
arr
cleaner
and

ENGINE
AND
IGNITION
TUNE
UP
4

25

block
the
throttle
and
choke
m
the
WIde

open

position

3
Remove
all
four

spark
plugs

4

Sequentially
press
a

compressIOn
test

gauge

mto
each
of
the

spark
plug
holes
and
crank
the

engme
for
at
least
four
strokes
Record
the
com

pressIOn
readmg
for
each

cylmder
Standard

compressIOn
readmg
IS
171
Ibs
m
12
0

kg
cm
Mmlmum

acceptable
readmg
IS
159

lbs
m
2

11
5

kg
cm

5
No

readmg
should
be
less
than
80
of
the

highest
cylmder
reading
ExceSSive

vanatiC
ns

between

cylmders
accompanied
by
low

speed

mlssmg
of
the

cyhnder
or

cylmders
that
read

low

usually
mdlcates

a
valve
not

properly
seat

mg
or
a
broken

piston
ring

Low

pressures
even

though
uniform

may

mdicate

worn

nngs
ThIS

IS

especlall
true
1f
ex

cessive
011

cQIlsumptlon
has
been
noticed
If
one

or
more

cylmders
read
low

or
uneven

inject

about
a

tablespoon
of

engine
ail

on

top
of
the

piston
of

that

cylinder
and
crank
the

engine

several
tlmes

noting
the

compressIOn
reading

If

compressIOn
has
nsen
the

piston

nngs
or

cylmders
are
worn
and
should

befserviced
If

compressIOn
has
not

unproved
after

addmg
oil

the
valves
are

Stlcking
or
are
not

seating

prop

erly

If
two

adjacent
cylmders
have
low

compres

sion
and

mjectmg
01

9es
not
increas
the
read

mg
the
head

gasket
between
the

cylmders
IS

probably
leaking

VALVE
CLEARANCE
ADJUSTMENT

Valve

adjustment
should
be
done
in
two

steps
first
With
the

engme
cold
and
then
at

operatmg
temperature
Refer
to

Figure
6

and

proceed
as
follows

1
Remove

arr
liter

2
Remove
rocker

arm
cover
Take

care
not
to

damage
the

gasket

3
Remove
the

spark
plugs
and

rotate
the
en

gine
unt1l
number
1

cylinder
IS
at

top
dead
center

o
l
the

compressIOn
stroke
This
can
be
de

tepnmed
w
hen
the

top
dead
center
mark
on

the
crankshaft

pulley
is

m

alignment
With
the

statIOnary

pomter
and
both
valves
for

number

1

cylmder
are
closed

I
4

Counting
from
the
front
of
the

engme
ad

Just
valves
1
2
3

and
5
as
follows
Loosen
the

pivot
lockmg
nut
and
turn
the

pivot
screw
unt1l

clearance
between
the

pivot
screw
and
the
rock

er
ann
IS
0
0079

m
0
200mm
for
the
mtake

valves
and

0
0098
in
0
25mm
for
the

exhaust

valves
Check

clearances
With

a
feeler

gauge
as

shawn
When
correct

tlghten
the

pivot
locking

nut

l

1

5
Rotate
the
crankshaft
unt1l
the
number
4

pISton
IS
at

top
dead

center
an
the

compressIOn

stroke
This

IS
one

complete
revolution
of
the

crankshaft

Agam
the
0

degree
mark
should

align
With
the

pomter
and
both

valves
on
num

ber
4

cylinder
should
be
closed

6

Adjust
valves
4
6
7
and
8

as
above

i

I

7

Replace
spark
plugs
Ignition
WIres

r
ick
r

1

arm
cover

gasket
and
air
filter

8
Start

engine
and

run
it
unt1l

operating
tem

perature
IS
reached

9
Remove
rocker

ann
cover
and

repeava
iius

ment
Clearances
should
be

0
0098

m
0

25fumj

for
the

mtake
valves
and
00Il8
m
0
30mi

for
the
exhaust
valves
Check
clearances
before

loosening
the

pivot
lockmg
nuts
as

they

may

already
be

properly
set
If

not

adjust
as
re

quir
l

ADDmONAL

CHECKS

l

Qunng
tune

ups
check
the

followmg
Ite

far

SignS
of
defects

or
excessive
wear
I

i

1

Inspect
the
carburetor
for

buildup
of

foreign

matenal

Pay
Special
attention
to
the

throat
and

linkages
Clean
or
overhaul
as

required
Det8
1ls

for
carburetor
mamtenance
are

given
in

Chapter

seven

38

CHAPTER
SIX

EMISSION

CONTROL
DEVICES

All

Datsuns
have
a
sealed

type
of
crankcase

emISSion
control
device
and
an
exhaust
emISsion

control
deVice
Models
sold

m
Cahfornla

smce

1970
also
have
an

evaporative
emisSion

control

deVice
An

rmportant
part
of
the

exhaust
control

device
is
the
air

pump
located

at
the

bottom
left

hand
side
of
the

engme
It

IS
dnven

by
a
belt
off

of
the
crankshaft

pulley
and

supphes
air
to
the

exhaust

system
In
1972

an
electric
blower
in

corporated
m
the

air
cleaner

replaced
the

mechanical

pumI

ENGINE
REMOVAL

Expenence
has

shown
It
IS
easier

to
remove

the

engine
and

the
transmission

as
a

smgle
UnIt

than

to
remove
the

engme
alone
Once

the
en

gine
and

transmiSSIon
are

out
of

the
vehIcle
the

tranSmIssion
can
be

detached
from
the

engme

To
remove
the

engme
transmISsion

proceed

as
follows

1
Scribe

ahgnment
marks
on
the
hood

around

the

hmges
ThIS

will
make
remstallatlon

eaSIer

2
Remove
the

two
bolts
that
secure

each

hInge

and

remove
the
hood

It
is

not

necessary
to
re

move
the
hood

support
from

the

engme
firewall

3

DISconnect
the
lower

radIator
hose

from
the

right
hand
SIde
of
the

engine
and
at
the
bottom

of
the
radIator
ThIS
will

pernnt
coolant
to
dram

from
the

engme
and
the

radIator

4

Remove
the
draIn

plugs
from
the

engine

pan

and
translIDSsIon

and

completely
dram
lubn

cants
Into
suitable

contamers

5
DISconnect

the

battery
cables
from

the
bat

tery
loosen

the
two
hold
down

clamps
and

re

move

the

battery

NOTE

The
location
and

number

of

hoses

to
be
removed

from
the
air

cleaner
varies

from
model
to

model

It
IS

normally
easier
to
remove

the

hoses

from
the
sources
rather

than

try

to

dISconnect

them

from

yndemeath

the

air

cleaner
The
1972
model

Will

requlre
dlsconnectlOn

of
the
electrica1

cirCUit

In
the
air

cleaner

system
wing
nut
from
the

top
of
the
air
cleaner
and

remove
the

aIr
cleaner

7
DIsconnect
the

upper
radiator
hose
from
the

radiator
and
the
thermostat

housmg
Remove

the
hose

8
Disconnect
the
two
heater

hoses
from

the

nght
hand
side
of
the

engme
TIe
these
bac
so

they
won
t
interfere
with

removal
of
the

engme

9
Remove
the
radIator

grille

by
unscrewing
all

mountmg
screws

10
Remove
the
four

mounting
screws

holding

the
fan
shield
to
the
backside

of
the

radiator

11
Remove
the
four

mountmg
bolts

holdIng
the

radiator

In

place
In
automatic
tranSmISsion

models
dISconnect

the
two
transnnsslOn
oIl

cooler

lInes
from

the
bottom
of
the
radiator

Pull
the

radiator

straight
up
to
remove
Remove

the
fan

shield

12
Loosen

the

adjustment
and

mounting
bolts

from

the

retamIng
brackets
on
the
alternator

and

air

pump
If
so

eqwpped
The

alternator
is
lo

cated
at
the
bottom

nght
hand
Side
of
the

engme

and
the
air

pump
on
the

lower
left
hand
Side

13
Loosen
tenSIon

on
the

two
dnve
belts

re

move
the
belts
from

the
alternator
and
air

pump

and
then
from
the

fan

pulleys

14
Remove
the
bolts

holdIng
the
fan
and

pulley

to
the
water

pump
assembly
and
remove
the

fan
and

pulley

15

DISconnect
the
fuel
hne
from
the
fuel

pump

16
DIsco

ect
accelerator

control

linkage
and

choke

WIre
at
the
carburetor

17
Disconnect

the

wiring
from

the
starter

motor
alternator

Ignition
coIl
oIl

pressure

switch

and

temperature

transmItting
unit

NOTE
The

following

steps
are

per

formed

from
under
the
car
lack

up

the

front
of
the

car
and

position

stands
under

the

front
support

points

to

proVide

working
room

under

the

vehicle

WARNING

Never

climb
under
a
vehicle
that
is

supported
by
the

lack
only
If
stands

are

not
avflllable

sturdy
wooden

blocks
can

be
U3ed

6
Disconnect
all
hoses

that
lead
to
the

air

cleaner

remove
two

bolts
that
hold
the
air

cleaner
to

its

mountmg
bracket

unscrew
the
18
Remove
two
bolts

holdIng
the
clutch

operat

Ing
cylInder
to
the

flywheel
hOUSIng
shown

m

ENGINE
59

2
Coat

the

pan
gasket
on
both
sides
With

gasket

compound
and
attach
the

oil

pan
to
the

cyhnder

block

Torque
as

specIfied

Manifold
and
Carburetor
Installation

1
Install
the
mtake
and
exhaust
manIfolds
WIth

associated

gasket
to
the

cylmder
head

2
Mount
the
carburetor
and

gasket
to
the
mtake

manIfold

2

Adjust
all
mtake
and
exhaust
valves
to
the

specIfied
clearance
for
a
cold

engme

Clutch

Assembly
Installation

CAUTION

Take

extreme
care
not
to

get
grease

or
011
on
the

clutch
or

flywheel
frlc

hon
contact

surfaces

1
Place
the
clutch
disc

assembly
on
the

flywheel

With
the

longer
chamfered

splmed
end
of
the
dISC

toward
the
transmISSion

2

Visually
align
or
use
a

dummy

splmed
dnve

shaft
to

ahgn
the
diSC

assembly
With
the

flywheel

pilot
beanng

3
Install
and

tighten
the
SIX
bolts

holdmg
the

clutch
cover

assembly
to
the

flywheel
Tighten

the
bolts
a
turn
each
tune

by
diagonal
pattern

until

they
are

tight
Tlghtenmg
torque
should
be

174

to
188ft
lbs
24
to
2
6

kg
m

NOTE
There
are
two
dowels
on

the

flywheel
to

locate
the
clutch
cover

4
Remove

dummy
shaft
If
used

after
the

above
bolts
are

fully
tightened

5
Refit
the
release

bearing
and
translI11Ssion

case
Miscellaneous
Installation

1
Connect
the
fuel
hose

on
the
front

part
of
the

engme
to
the
fuel

pump
and
to
the
carburetor

2

Gap
the

spark
plugs
and
mstall
them

usmg

new

gaskets

3
Coat
the
rocker
arm
cover

gasket
With
sealer

and

position
It
on
the

cylmder
head

4
Install
the
rocker
arm
cover
and

tighten
the

two
thumb

screws
that
hold
it

m

place

5
Install
distrIbutor

makmg
certam
that
the

notch

on
the
distributor
shaft

assembly
mates

With
the
drive

spmdle
Ahgn
the
location
marks

made

dunng
disassembly
so
that
the
distrIbutor

is

positioned
as
before

6

Install
and

tighten
the
bolts
which
hold
the

dIStributor

to
the
front

cover

7
Install

pomts
condenser
and
rotor

8

Replace
distrIbutor

cap
and
attach

spark
plug

Wires
m
the
correct

sequence
Make
certain
that

all
wires
are

firmly
seated
m
the
distrIbutor

cap

and
attached

securely
to
the

spark
plugs

9
HOISt
the

engme
assembly
from
the
work

stand

10
Install
the
alternator
bracket
alternator

and

engme
mounts
to
the
block

11
Install
the

IgnItIon
coil
oil
filter
oil

pressure

SWitch

dipstick
and

water
drain

plug

12
Connect
the

vacuum
Ime
between
the
dis

trIbutor
and
carburetor

13
Connect
the
transIDlSSlOn
to
the

engine
prior

to
mstallatIon
m
the
vehicle

Engine
Installation

Installation
is
the

reverse
of
the

procedures

followed
m

removal
Be
certaIn
thatlall

battery

connections
are
made

that
water
hoses

are
se

cured

wmng
IS
connected

properly
and
that
all

required
bolts
and
mounts
are
mstalled
and

tightened
Replace
the
radiator
fan
belts
and

radiator
shroud
Fill
the

engme
With
the

proper

grade
of
oil
and
the
radiator
With

recommended

coolant
Install
the
hood

to
the

hInges
according

to
the
marks
made

dUrIng
removal

SERVICE
DATA
AND
SPECIFICATIONS

Table
1
covers
servIce
data
and

engme
Speci

fications

CHAPTER

NINE

ENGINE
ELECTRICAL
SYSTEM

The
electrIcal

system
has

undergone
slIght

yearly
changes
the
most

SignIficant
being
ill
the

distrIbutor
Some
models
have
a

smgle
contact

pomt
whIle
others
have

a
dual

pomt
system
De

talls

are
covered

m
the
dIstrIbutor
sectlon
The

electrIcal

system
IS
a
12
volt

negatIve
type

OPERATION

Figure
1
shows
the

starter
motor
When
the

Ignltlon
sWItch

IS
turned

to
the

start

pOSItIon

current
flows

through
the

senes
and
shunt
colis

of
the

magnetIc
SWitch
and

magnetizes
It
The

plunger
IS

pulled
mto
the

sWItch

operatlng
the

shIft
lever
to

engage
the
dnve

pmlon
with

the

flywheel
rmg
gear
and
to
close
the

magnetIc

SWitch

CD
Figure
2
shows
the
starter
motor
CIrcUIt
Clos

ing
of
the

statlonary
and
movable
contacts
cause

the
motor
to
crank
the

engme
and
cut
out
the

series
coIl
of
the

magnetic
switch
The

magnetic

pull
of
the
shunt
coll

IS
suffiCIent
to
hold
the

pmIOn
m
mesh
With
the

flywheel
nng
gear
after

meshing
has
occurred
After
the

engme
starts

and
the

Ignition
key
IS
released
to
the
on

POSI

1

CD

12
11
10

1

Stationary
contact
8
ShIlt
le
er

2
Sene
coli
9
Orne

pinion

3

IgmtlOn
SWitch
10

Ring

gear

4
Solenoid
11
Plmon
slee
e

spllng

5

Shunt
COil
12
Armature

6

Plunger
13
Movable
contact

7
Return

spllng
14

Battery

ENGINE
ELECI
RlCAL
SYSTEM
97

No
Load
Lock

Torque
Test

1
Connect
the
starter
motor
in
series
with

a

12
volt

battery
and
antmeter
as
shown
in

Figure

19
The
antmeter
should
be

capable
of

mdIcatIng

1
000

amps

@
Switch

Voltmeter
Ammeter

2
Use

torque
testlng
equipment
to
determine

the

torque
the
motor

develops

3
Connect
a
voltmeter
and
a
vanable
resistor

WhICh
IS
used
to

regulate
the

voltage
Into
the

circwt

4
Close
the
sWitch

and

regulate
the

voltage
as

reqUIred
Figure
20

proVIdes

power
voltage

amperage
and

torque
mformatIon

that
1f
fol

lowed
will
mdIcate
the
condItion
of
the
starter

motor

Power
kw

Voltage
v

@

Test

Diagnosis

1
Low

speed
with

high
current
draw

might
re

sult
from

tIght
dirty
or
worn

bearings
bent

armatlIre
shaft
loose
field
call
or
a
shorted

armatlIre

2
Fatlure
to

operate
With

htgh
current
draw

may
result
from
a

gromlded
or

open
field
coil
a
defectIve
armature
coll
or
a
burned

out
com

mutator
bar

3
Low

torque
low
current
draw
and

low

speed

would
be
caused

by
hIgh
Internal
reSIStance
due

to
loose
connectIons

dirty
commutator
defec

tIve
leads
and

a
burned
out
commutator
bar

4

HIgh
speed
With
low

torque
would
be
caused

by
a

grounded
field
coll

Magnetic
Switch

Assembly
Test

H
the
above
tests
are

satIsfactory
check
the

magnetIc
SWitch

assembly
as
follows

1
Connect

Jumper
cables
between
the

negative

battery
tennmal
and
the
starter
motor
M
term

inal

as
shown
In

Figure
21
Also
connect
the

positIve
battery
terminal
to
the
S
terminal
and

place
a
SWitch
m
senes
in
the
CIrCuit

@
Ignition
switch

9

I

i
j

Battery
Starter
motor

rr

2
Close
the
SWitch
and
measure
the

dimension

given
m

Figure
22
The
dimensIon
should
be
as

specIfied

o
0591m

15mm