1968 DATSUN 510 fuel type

4

CHAPTER
ONE

chassIs

number
Write
the
numbers
down
and

carry
them
ill

your
wallet

Service
Hints

Throughout
thIs

manual
keep
two
conven

bons

ill
mmd
Front
refers
to
the
front
of
the

vehicle
The
left
and

nght
sides
of
the

ve

hicle
refer
to
a

person
sittIng
ill
the

car

facing

forward
For

example
the

steenng
wheelIS

on

the
left
hand
Side
All
dimensIOns
and

capacities

are
expressed

ill
units
fanuhar

to
a
Umted

States

mechaniC
such
as
illches
and

pounds
Metric

measurements

are
also

given
Metnc

tools
are

reqUITed
to
work

on
the
Datsun
CD

DATSUN

IENGINE
CAPACITY

IMAX
HP
RPM

IWHEELBASE

IENGINE
NUMBER

FAR
NO

NlSSAN

MOTOR

co
LTD

YOKOHAMA
JAPAN
TYPEI
510

1595
cc

961P
6600

rpm

mm

L

1
00988

P61
l
O
1
l
M

Table
1
MAIN
SPECIFICATIONS

AND
DIMENSIONS

r
ITEM
Sedan

Wagon
Plm

up

EnglDe
Type
L16

L16
L16

Valve

Arrangement
Overhead

Cam
Overhead
Cam
Overhead
Cam

Bore
3
26n
ID
83mm

3
2677
ID
83mm
3
2677
ID
83mm

Stroke
2902
ID

73
7mm
2
902
ID

73
7mm
2
902
In

73
7mm

Displacement
97
3
cu
ID

l595cc
97
3
cu
In

l595cc
97
3
cu
ID
1595cc

CompressIOn
Ratio
851

851
851

MaXimum
SAE

Hompower
96

@
5

600

rpm
96

@
5
600

rpm
96

@
5
600

rpm

MaXimum
SAE

Torque
998ft
Ib
138

kg
m
998ft
Ib
138

kg
m

9911
ft
Ib
138

kg
m

Fuel
Octane
85

85
85

Lengtb
1622
ID

4
12Omm
163
2
ID
4
I45mm
168
9
ID
4
290mm

Width

61
4
ID

l
560mm
61
4
ID
1
560mm
62
8
In

Cl
595mm

Height
55
lID
1
400mm
565
ID

Cl
435mm
60
8
ID

Cl
545mm

Wheelbase

95
3
ID

2
42Omm

95
3
ID

2
420mm
99
6
In

2
530mm

Room

Space

Inner

Length
63
3
In
1
61Omm
673
ID

1
710mm
72
8
ID

1
850mm

Inner
Width

499
ID
1
27Omm

507
ID

1
29Omm
563
In

1
430mm

Inner

Height
44
4
In
1
130mm

44
61D
1
135mm
15
7
ID

399mm

Tread

Front

50
4
ID

28Omm
502
In
1
275mm
492
In
1
250mm

Rear
504
In

1
280mm
496
In

Cl
260mm
499
ID
1
267mm

Road

Clearance
741n

l88mm
64
ID
l63mm
787
ID
200mm

Weight

4

Speed
2
0611b
935

kg
2
138
Ib

970

kg
2
127
Ib
965

kg

Automatic

2
114Ib
959

kg
2
182
Ib
990

kg

Minimum

Turning
RadiUS
157ft
48m

157ft
48m
171
ft
52m

Seating

Capaaty
5

5
2

Battery

Volt

12

12
12

Capacity
400rSOAH

400r50AH
40
or
60
AH

Connection

Negative
ground
Negative
ground
Negative
ground

Fuel

Tank

Capaaty
11

9

gal
45
liter
11
9

gal
45
liter
108

gal

41J
r

011

Pan

Capacity
42

qts
40

liter
4
2

qb
40
liter

1
06

gal
40
Iller

011
Filter

Capaaty
74

ql
07
liter
74

ql
0
7
liter
1
48

Pint
0
7
liter

Transmission

Capaaty
1
8

ql
1
7
liter

18

ql
1
7
Iller
2
11

qt
20
Iller

Dlflerenbal

Capaaty
85

ql
80
liter
11

ql
1
0
liter
87

ql
0
83
lIter

Coolant

Capaaty
7
2

ql
6
8
liter
7
2

ql
6
8
lIter
7
2

qt
6
8
Iller

Clutch

Type

Dry
Single
diSC

Dry
slDgle
diSC

Dry
slDgle
diSC

Draphragm
spnng
Diaphragm

spnng
Diaphragm

spnng
l

CHAPTER
THREE

TROUBLESHOOTING

TroubleshootIng
the
Datsun
can
be

relatlvely

simple
1f
done

lOgically
The
first

step
must

always
be
to
define

symptoms
as

closely
as

pos

Sible

Subsequent
steps
mvolve

testIng
and
an

alyzmg
areas
which
could
cause
the

symptoms

Procedures
m
thiS

chapter
analyze
typical
symp

toms
and

give
lOgical
methods
of
isolation

These
are
not
the

only
methods
There

may
be

several

approaches
to

solvmg
a

problem
but
all

must
have
one

thmg
m
common
a

lOgical

systematic
approach

TROUBLESHOOTING
EQUIPMENT

The

followmg
eqUipment
is

necessary
to

prop

erly
troubleshoot
an

engme

1
Voltmeter
Ammeter
and
Ohmmeter

2

Hydrometer

3

Compression
Tester

4
Vacuum

Gauge

5
Fuel
Pressure

Gauge

6

Dwell
Meter

7
Tachometer

8

StroboscopiC
Trming
Light

9
Exhaust
Gas

Analyzer

Items
1

through
8
are
essentlal
Item
9

is

necessary
for
exhaust
elDlSSion
control

comph

ance
The

followmg
is
a
bnef

description
of
the

functlon
of
each
mstrument
Voltmeter
Ammeter
and
Ohmmeter

For

testIng
the

ignitlon
and
electncal

systems

a

good
voltmeter
is

reqUIred
For
automotIve

use
an
mstrument

covenng
0
20
volts
is
salls

factory
It
should
have
an

accuracy
of
about

Ih

volt
which
excludes
the
common
auto

moUve

type
found
in
instrument

panels

An
ohmmeter
measures
electncal
reSiStance

and

is

reqUired
to
check
electncal

contInUity

open
and

short
circwts
and
for

testing
fuses

and

hghts

The
ammeter
measures
electncal
current
One

for
automotIve
use
should
cover
0
10
and
0
100

amperes
An
ammeter
is
useful
for

checkmg
bat

tery
chargmg
and

startIng
current
The
starter

and

generator
procedures
m
tlus
manual

use
an

ammeter
to
check
for
shorted

wmdmgs
Several

inexpensive
VOM
s
volt
ohmmeters
combme

all
mstruments
and
fit

easily
mto

any
tool
box

The
ammeter

ranges
are
often
too
small
for

auto

motIve
work

thougll

Hydrometer

A

hydrometer
is

necessary
to
check

battery

condition
and

charge
It
measures

specific
grav

ity
of
the

electrolyte
in
each
cell

Compression
Tester

The

compressiOn
tester
measures

compression

10
CHAPTER
THREE

pressure
bUllt

up
In
each

cylInder
The

readIngs

when

properly
Interpreted
IndIcate

general
cyl

Inder
and
valve
condltlOn

Vacuum

Gauge

The
vacuum

gauge
IS

easy
to
use
but
dIfficult

for
an

Inexpenenced
mechanIC
to

Interpret
The

results
when
conSIdered
WIth
other

findIngs
can

prOVIde
valuable
clues
to

pOSSIble
trouble

Connect
the
vacuum

gauge
WIth

a
T
connec

tIon
In
the
hose
from
the
carburetor
to
the

vacuum
advance
on
the
dIstnbutor
Start
the

engme
and
let
It
warm

up
thoroughly
Vacuum

readIng
should
be

steady
at
18
22
Inches

NOTE
Subtract
1
Inch

from

reading

for

every
1000

feet
of
altitude

Figure
1
shows
numerous

tYPical
readIngs

WIth

InterpretatIons
Results
are
not
conclusive

WIthout

companng
to
other
tests
such
as
com

preSSIOn
readIngs

Fuel
Pressure

Gauge

ThIS
Instrument

IS
VItal
for

evaluatIng
fuel

pump
performance
Often

a
vacuum

gauge
and

fuel

pressure
gauge
are
combIned

Dwell
Meter

A
dwell
meter
measures
the
dIstance
In
de

grees
of
cam
rotatIon
that
the
breaker

pOInts

remaIn
closed
while
the

engme
IS

runnIng
SInce

thIS

angle
IS
determmed

by
breaker

pOInt
gap

the
dwell

angle
IS
an
accurate
IndIcatIon
of

pOInt

gap
Many
tachometers
Intended
for

tunIng
and

testIng
Incorporate
a
dwell
meter
as
well
Follow

the
manufacturer
s
InstructIon
to
measure
dwell

on
the
Datsun

Tachometer

A
tachometer
IS
essential
for

tunIng
Datsuns

WIth
exhaust
emission
control
deVices

IgmtIOn

turung
and
carburetor

adjustments
must
be

per

formed
at
the

specified
Idle

speed
The
best
In

strument
for
thIS

purpose
IS
one
WIth

a

range
of

0
1
000
or
0
2
000

rpm
Extended

range
0

6
000
or
8
000
Instruments
lack

accuracy
at

lower

speeds
The
InStrument
should
be

capable

of

detecting
changes
of
25

rpm
Stroboscopic
Timing
Light

ThIS
Instrument

pernuts
accurate

IgnitIon

tImIng
By
f1ashmg
a

bght
at
the

preCISe
Instant

cylInder
No
1
fires
the

posItIon
of
the
crank

shaft

pulley
at
that
Instant

can
be
seen
Marks

on
the

pulley
bne

up
With

a
reference

pOInter
on

the
block

dunng
the

tIming
procedure
SUltable

bghts
are
neon
bulb

types
and
xenon
strobe

hghts
Neon

tunmg
bghts
are
ddticult
to
see
and

must
be
used
in

dImly
bt
areas
Xenon
strobe

bghts
can
be
used
In

bnght
sunbght
Use
the

bght
accordIng
to
the
manufacturer
s
InStruC

tIons

Exhaust

Analyzer

Of
all
Instruments
descnbed
here
this

IS
the

least

bkely
to
be
owned

by
a
home
mechanic

One
Instrument

samples
the
exhaust

gases
from

the

taIlpIpe
and
measures
the
thermal
conduc

tIVIty
of
the
exhaust

gas
SInce
different

gases

conduct
heat
at

varYIng
rates
thermal
conduc

tIVIty
of
the
exhaust
IS

a

good
IndIcatIon
of

gases

present
This
Instrument
IS
VItal
for

accurately

checkIng
the
effectIveness
of
exhaust
emIssion

control

adjustments
but
IS
too

expenSIve
for
an

amateur
mechanIC
to
conSIder

buying

STARTER

Starter

system
troubles
are

relatIvely
easy
to

ISolate
The

followmg
are
common

symptoms

and
cures

1

Engme
cranks

very
slowly
or
not
at
all

Turn
on
the

headhghts
If
the

bghts
are

very
dun

most

likely
the

battery
or
the

connecting
WireS

are
at
fault

Check
the

battery
using
the

pro

cedures
descnbed

in
the
Tune

up
chapter
Check

wmmgfur
e
s
wom
andd
connectIom

H
the

battery
and

connectIng
WIres
check

good
turn
the

headlIghts
on
and

try
to
crank
the

engIne
H
the

lIghts
dIDl

drastIcally
the
starter
is

probably
shorted
to

ground
Remove
the
starter

and
test
it

usmg
the

procedures
gIven
in

Chapter

NIne
If
the

lights
remain

bnght
or
dun

slIghtly

when

crankIng
the

engme
the
trouble

may
be
in

the
starter
solenOId
or

wmng
To
ISolate
the

trouble
short
the
two

large
solenoid
ternunals

together
not
to

ground
if
the
starter
cranks

normally
check
the
solenoid
and

wmng
up
to
the

22
CHAPTER

FOUR

CD

Normal

plug

appearance
noted

by
the
brown
to

graYish
tan

deposits
and

slight
electrode

wear
This

plug
rndlcates
the
correct

plug
heat

range
and

proper
air
fuel
ratio

f

j

l

Carbon

fouling

dlstrngUlshed
by
dry
fluffy
black

carbon

deposits
which

may
be
caused

by
an
over

nch
alr
fuel
mixture
excessIVe

hand

chokrng

clogged
air
filter

or
excessive
Idling

lJ
6

1

4i

Z

011

fouling
rndlcated

by
wet

OIly

depOSits
caused

by
011

pumprng
past
worn

rrngs
or
down
the
rntake

valve

gUides
A
hotter

plug
temporanly
reduces
011

depOSits
but
a

plug
that
IS

too
hot
leads
to

pre

IgmtlOn
and

possible
engrne
damage
Red
brown

yellow
and
white

coatrngs
caused

by

fuel
and
011
additives
These

depOSits
are
not
harm

ful
If

they
remarn

rn
a

powdery
form

C

I

Shrny
yellow
glaze
on
rnsulator

cone
IS
caused

when

the

powdery
depOSits
from
fuel
and
011
additives

melt

Meltrng
occurs
dunng
hard

acceleration
after

prolonged
Idling
This

glaze
conducts

electnclty

and
shorts

out
the

plug

Overheated

plug
rndlcated

by
burned
or
blistered

rnsulator

tip
and

badly
worn
electrodes
This
condl

bon

may
be
caused

by
pre
Igmtlon
cooling
system

defects
lean
air

fuel
ratiOS
low
octane
fuel
or
over

advanced

Igmbon
bmrng

Spark
plug
condition

photos
courtesy
of
At

Spark
Plug
DIvision
General
Motors

Corporation

The

procedures

given
below
would

generally

apply
to
eIther

type
In
the
dual

pomt
system

one
set
of

pomts
IS
known
as
the
advance
set

and
the
other
the
retard
set

Complete
details

are

given
m

Chapter
Nme

Figure
4
IS
a
detaIl

of

the
dual

pomt

system

1
Remove
dIStnutor

cap
Clean

It

carefully
to

remove

grease
or
dIrt

2
Examme
the
mSIde
of
the

cap
for
d1rt
or
ex

ceSSIve
wear
Look
for

SIgns
of
carbon
tracks
arcmg
from
contact
to
contact
mSIde
the
dIS

trIbutor

cap
Carbon
tracks
mdlcate
defects
or

cracks
and
If
found
the

cap
should
be

replaced

3
Remove
the
rotor
and

mspect
for
exceSSIve

wear
around
the

top
metal
contact

wiper
surface

If

defectlve
replace
As

a
matter
of

good

prac

nce
the

rotor
should
be

replaced
whenever
the

contact

pomts
are

replaced

4
Use
a
screwdriver
to

gently
open
the
contact

pomts
If

they
show
wear
or

plttmg
remove
the

I

7
r

ENGINE

37

CD

4

11lL

8

311
@
2S

10

32
@
@
24

33
Q
23

1
21

rl
qp

12
26

27

19
34

30

31
1
25

@
24

W
32
@

30

33
0

21

28
tJ

2S
ctJ5J

27

20

II

27

Inner
valve
seat

spnng

1
Camshaft

10
Camshaft
cham
19
Intake
valve

28
Valve
011
seal

2
Camshaft
dowel

11
Chain
tensloner
20
Exhaut
valve

29
Valve
rocker

4
Cam

locating
plate
12
Hex
bolt
21
Valve

spnng
30
Valve
rocker
WIth

pad

5

Spnng
washer

13

Spnng
washer
22
Valve

spnng
31
Valve
rocker

Pivot

6
Hex
bolt

14
Chain
tension
Side

gUide
23
Valve

retamer
32
Pivot
ICICk

nul

7
Cam
sprocket
15
Chain
tension
slack

gUide
24
Valve
collet

33
Rocker

retainer

8
Cam

gear
bolt
16

Spnng
washer
25
Rocker

valve
guide
34
Rocker

valve

spnng

9
Fuel

pump
earn

assembly
17
Hex
bolt
26

Valve
seat
35

Rocker

bushing

vious

chapter
for

specmcaoons
and
mamten

ance
CARBURETOR

The
carburetor

IS
a

smgle
two
barrel
down

draft

type
From
1968

through
1971
the
car

buretor

on
manual
transmissIOn
models

has
a

hand
choke

control
1972
models
are

eqUIpped

With
an
automatic
choke
much
the

same
as
has

been

used
on
all

automaoc
transmISSion
models
FUEL
PUMP

The
fuel

pump
IS
on
the
front

right
hand
Side

of
the

engme
Just
below
the
rocker
arm
cover

It

IS
a

diaphragm
type
dnven

by
the
camshaft

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

CHAPTER
SEVEN

FUEL
SYSTEM

The
fuel

system
mcludes
the

fuel

tank

straIner

pump
carburetor
arr
cleaner
and

necessary
lines

Inspect
components
for
leaks

and
deterioratIOn
whenever
mamtenance
is

done
The
fuel
stramer
should
be

mspected
peri

odIcally
and
cleaned

AIR
CLEANER

The
au
filter
element
is
viscous

paper
and

does
not

require
cleanmg
Replace
It

every

24
000
mlles
or
more

frequently
under
harsh

condItIons

Several
mInor
differences
exist
between

vehicles

dependmg
on
the

type
of
emisSIOn
con

trol
device
used

Figure
1
shows
location
of
the

air
cleaner
on
the

engme
and

parts
compnsing

the
cleaner

system
on
model

years
through
1969

Figure
2
shows
the

changes
for
1970
and
later

Warm
air
is

supplIed
to
the
air
cleaner
from
the

exhaust
mamfold
to

prevent
carburetor

Icmg

AIR
CLEANER
REMOVAL

AND
REPLACEMENT

1
Unthread
the

WIng
nut

atop
the
cleaner

assembly

2
Remove
the
two
bolts

holdIng
the
air
cleaner

to
the

support

3

Disconnect
the

aIr
cleaner
duct
from

the
base

of
the
cleaner
intake
throat
4
LIft
off
the
aIr
cleaner

body
and
remove
the

aIr
filter
as
shown
m

Figure
3

To
remove
the
arr
cleaner

proceed
as
follows

1
Perform

steps
1

through
4
above

2
Unscrew
the
band
bolt
at
the
base
of
the

air
cleaner

3
DIsconnect
all
hoses

leadmg
to
the
air

cleaner

4
Pull

up
on
the

body
of
the
air
cleaner
and

remove
from
carburetor

5

Except
for
the

au
filter

element
thoroughly

clean
all

parts

6
Reverse
the

steps
above
for

reassembly

FUEL
STRAINER

The
fuel
stramer

IS
located
on
the

nght
hand

side
of
the

engme
compartment
Figure
4
shows

the
fuel
stratner
hoses

clamps
and
the
mount

Ing
clIp
that
holds
the
fuel
stramer
In

place
The

fuel
stramer
IS
of
the

cartrIdge
type
and
uses
a

fiber
mat
and

nylon
as

strainer
elements
The

fuel
stramer
should
be

mspected
frequently
for

foreIgn
material
and

replaced
at
least

every

24
000
rmles

1
DIsconnect
the
inlet

and
outlet
hoses
from

the
fuel
stratner
Make
certatn
that
the
mlet
hose

bottom
IS
not

permItted
to
fall
below
the
level

of
the
fuel
tank

or

leakage
wIll
occur

FUEL
SYSTEM
69

CARBURETOR

The
carburetor
IS
an
Hltach1

Type
DAF328

Several
varIations
are
used

dependmg
on
the

model

year

type
of
transmissIOn
and
the
emIS

SIon
control

system
The
dIfferent
models
are

the
same
as
far
as
basiC

operation
IS
concerned

Therefore
the

followmg
dISCUSSIon
covers
a

typIcal
carburetor
The

automatIc
choke
IS
used

on
automatIc
transmISSIon
and
1972
models

only
All
other
chokes
are
manual

Refer
to

Figure
8
The
carburetor
conSIsts
of

a

pnmary
system
used
m
normal

runnmg
and
a

secondary
system
used
for

hIgh
speed
or

heavy

load

operatIons

CARBURETOR
ADJUSTMENT

Idling
Adjustment

Idle

adjustment
IS
made

by
the
throttle

adjust

and
Idle

adjust
screws
both
of
wh1ch
are
located

at
the
bottom
of
the
carburetor

1

Screw
the
Idle

adjust
screw
all
the

way
in

to

the

fully
closed

pOSItIon
Do
not
over

tIghten

CD

6
2
Unscrew
the
Idle

adjust
screw

approXImately

three

cor
nplete
turns

3
Screw
m
the
throttle

adjust
screw
two
or
three

turns
and
start
the

engui
e

4
Screw
out
the
throttle

adjust
screw

slowly

until
the
onset

roughness
followmg
a

gradu81

speed
drops

5
Screw
m

the
Idle

aOJust
screw
untIl
the

engme

runs

smoothly
at
the

hIghest

speed

6

Readjust
the
throttle
screw
to

drop
the

engme

speed
Repeat
these

adjustments
untIl
a
smooth

engme
speed
at
the

proper
Idle

rpm
IS
ach1eved

Refer
to
the
tune

up
chapter
for

proper
rpm

Fuel
Level

Adjustment

Constant
fuel
level
IS
mamtamed

by
the
float

and
the
needle
valve

Figure
9
sb
ws
the
fuel

level

system
wlthm
the
carburetor
If
the
level
IS

at
the
lIne
on
the

f
lel
reservOir
level
is

properly

set
If
not

adjust
It

by
bendmg
the
float
seat

Adjust
the

gap
between
the
valve
stem
and
the

float
seat
to
00591
m

1
5mm
with
the
float

fully
luted

up
by
bendmg
the
float

stopper

1213141516

20

I

h

r

1
Secondary
main

nozzle

2
Secondary
small
venturi
10

Secondary
bypass
hole
18

Primary
slow
air
bleed

3

Secondary
main
air
bleed
11

Secondary
throttle
valve
19
Air
vent

4

Secondary
slow

Jet
12
Choke
valve
20
Level

gauge

5

Secondary
slow
air
bleed
13

Primary
main
air
bleed
21

Primary
main

Jet

6
Needle
valve
14

Primary
main
nozzle
22
Idle
limit
screw

7
Float
15
Economizer
bleed
23
Idle
hole

8

Secondary
emulSion
tube
16

Primary
slow

let
24

Bypass
hole

9

Secondary
main

Jet
17

Primary
economizer
25

Primary
throttle
valve