1973 DATSUN B110 gas type

ENGINE

INSPECTION

Check

the

upper
and
lower
bodies
for
cracks

2

Check
the
valve

assembly
for

wear
of
the
valve
and

valve

spring
Blow
the
valve

assembly
by
breath
to

examine
its

function

3

Check
the

diaphragm
for
small
holes
cracks

and

wear

4

Check
the
rocker

arm
for
wear
at
the

portion
in

contact
with

the
camshaft

5

Check
the
rocker
arm

pin
for
wear
since
a
worn

pin

may
cause
oil

leakage

6

Check
all
other

components
for

any
abnormalities

and

replace
with
new

parts
as

required
ASSEMBLY

Assembly
is
done
in
reverse
order
of

disassembly
For

reassembly
and

reinstallation
the

following
matters

should
be
noted

Use
new

gasket

2
Lubricate
the
rocker
arm

link
rocker
arm

pin
and

lever

pin
before
installation

3
To

test
the
function

position
the

fuel

pump
assem

bly
about
I

meter
3
3
ft
above
fuel
level
with
a

pipe

connecting
the
fuel

pump
and
the
fuel

strainer
and

operate
the
rocker

afm

by
hand
If
fuel
is
drawn

up
soon

after
the
rocker
arm
is
released

the
function
of
the

pump

is

satisfactory

CARBURETOR

CONTENTS

DESCRIPTION

STRUCTURE
AND
OPERATION
EF

8

EF

9

EF
10

EF
11

EF
12

EF
12

EF
12

EF
14

EF
14

EF
15

EF
15

EF
16

EF

16
Primary
system

Secondary
system

Anti

dieseling
solenoid
valve

Float

system

Electric
automatic
choke

ADJUSTMENT

Idling
adjustment

Fuel
level

adjustment

Fast
idle

adjustment

Vacuum
break

adjustment

Choke
un
loader

adjustment

DESCRIPTION

The
carburetors
are

of
a

downdraft

type
which
is

designed
and
built

to
increase

power
and

fuel

economy
as
Bi
metal

setting

Adjustment
of

interlock

opening
of

primary
and

secondary
throttle
valves

Dash

pot
adjustment

MAJOR
SERVICE
OPERATIONS

Removal

Disassembly

Cleaning
and

inspection

Assembly
and
installation

JETS

SERVICE
DATA
AND
SPECIFICATIONS

TROUBLE
DIAGNOSES
AND

CORRECTIONS
EF
17

EF
18

EF
18

EF
19

EF
19

EF
19

EF
21

EF
22

EF
22

EF
22

EF
22

well
as
to
reduce
the

emission
of
exhaust

gases

These
carburetors

present
several
distinct
features
of

importance
to
the

car
owners

A

summary
of
features
is
as
follows

EF
8

FUEL
SYSTEM

5
Check
venturi
clusters

for
loose
or
worn

parts
If

damage
or
looseness
exists

replace
cluster

assembly

6
Check
the

linkage
for

operating
condition

7

Inspect
the

operation
of

accelerating
pump

Pour

gasoline
into
the
float
chamber
and

operate
the

throttle
lever

Check
condition
of

gasoline
injection
from

the

accelerating
nozzle

Assembly
and
instalIetion

Assemble

and
install
the
carburetor
in

reverse

sequence

of

disassembly
and
removal

Replace
the

gaskets
if

necessary

When

disassembling
and

reassembling
the
interlock

link

and

related

components
be
careful
not

to
bend
or

deform

SPECIFICATIONS
AND
SERVICE
DATA

Carburetor
model

Applied
engine

Type

Outlet
diameter
mm
in

rom

in
Venturi
diameter

Main

jet

Main
air
bleed

Slow

jet

Slow
air
bleed

Power

jet

Float
level
H
rom

in

Interlock

opening
of

primary
and

secondary
throttle
valve
G
I

Throttle
valve

opening
480
mm
in

Auto
choke

Fast
idle

setting
clearance
A

mm

in

Manual
transmission

Automatic
transmission

Vacuum
break

gap
between

choke
valve
and

carburetor

body
8

mm
in

Manual
transmission

Automatic
transmission

EF
21
the

components

Reassembly
carefully
and

correctly
so
that

all
interlock

links

operate
smoothly

JETS

The
carburetor

performance
depends
on
jets
and
air

bleeds
and
the
vehicle
emissions

largely
depends
on

the

carburetor

performance
That
is

why
these

components

are
manufactured
with
utmost
care

To
clean
them

use

gasoline
and
blow
air
on
them

Changing
jet
or
air

bleed
size

may
cause
ill

vehicle

emission

So

they
should
not
be

changed
their

numbers

DCH3064
for

Manual
transmission

DCH306
5

for
Automatic
transmission

Downdraft

Primary
Secondary

26
1
024
30
1
181

20
0
787
26
1
024

1
95

1
140

1
80

1
80

1
43

1
50

1
215

1
100

1
60

18
to
20
0

709
to
0
748

5
8
0
2283

0

80
to

0
88
0
0315
to
0

0346

1
07
to
1
17
0
0421
to
0

0461

1
140
to
1
260
0
0449

to
0
0496

1

205
to
1

335
0

0474
to
0
0526

FUEl
SYSTEM

EVAPORATIVE
EMISSION

CONTROL
SYSTEM

CONTENTS

OESCRI
PTION

Flow

guide
valve

MAINTENANCE

AND

TESTING

Checking
fuel
tank

vapor

liquid
separator

and

vapor
vent
I
ins
EF
25

EF

26

EF

26

EF

26

DESCRIPTION

This

system
consists
of

four
basic
elements

indicated

below

I

Fuel
tank

with

positive
sealing
filler

cap
with
relief

valve

2

Vapor

liquid
separator

3

Vapor
vent
line

4
Flow

guide
valve

The
flow

guide
valve

prevents
blow

by

gas
from

flowing
into
the
fuel
tank

and

guides
fresh
air
into
it

preventing
gasoline

vapor
from

escaping
into
the

carbure

tor
air
cleaner

Fl

me
ester

I

f
Flow

Thev
lve

opens
when

thlp
1l

rO

Inch

Hg

O
Positive
unk

venlI1atlon

PCV
hoe
Checking
fuel

tank
vacuum
relief
valve

operation

Checking
flow

guide
valve
EF
27

EF
27

Flow

guide
valve

operates
and
blow

by

gas
and

gasoline

vapor
flow
as
follows

When
the

engine
is
not

running
the

vapor
vent

line

vapor
liquid
separator
and

fuel
tank

are
filled
with

gasoline
vapor
produced
in
the

sealed

type
fuel
tank

A

flow

guide
valve

opens
when
the

gas

pressure
is

above

IOromHg
0
4

in

Hg
The

gas

passed
through
the
flow

guide
valve
2
is

accumulated
in

the
crankcase

Once
the

engine
starts

evaporates
in

the
crankcase

manifold
and

carburetor
air
cleaner

is
sucked
into
the
manifold
for

combustion
When
the

pressure
of
the

sealed

type
fuel

tank

vapor
liquid

separator
and

vapor
vent
line

becomes

negative
by

decreasing
the
fuel
the

flow

guide
valve
I

opens
to
send
fresh
air
from
the
carburetor
air
cleaner

to

the

fuel
tank

lill
K
riquidllepilrflOr

T

VilPOl
vent

line
Positiveteilling

lillercap

Fig
EF
37

Evaporative
emission

control

system

EF
25