Vacuum Break; Choke Unloader - Datsun 620 Series 1977 Service Manual

EC527
Fig
EF 39 Mea
uring
throttle valve
clearance
MfT
AfT
3 To check fast
idling
cam
setting
by engine
speed proceed
as
follows
Warm up engine sufficiently
Set
Engine
Fuel
Fast
idling
earn
steps
o
04th
l
2nd
1st
EC528
Fig
EF 40 Fast
idling
cam
steps
2
The clearance should be
specified
value in the
following
table If
not
ad
just
the clearance
by turning
fast
idling
screw
Clearance
A
mm
in
1
33 to I 47 0 0524 to 0 0579
1
58
to 1
72
0
0622
to 0
0677
fast
idling
cam
at
2nd step
and read
engine speed
Fast
idling
cam
is
prop
erly set
if
engine
speed
is
within
Engine speed
rpm
Fast
idling
earn
MfT
AfT
VACUUM BREAK
I
Close choke valve
completely
2
Hold choke valve
by stretching
a
rubber band between choke
piston
lever and
stationary
part of carburetor
3
Grip
vacuum
break rod with
pliers
and
pull straight
out
4
Under this condition adjust
the
clearance
between choke valve and
carburetor
body
B in
Figure
EF 42 to specified
value by
bending
vacuum
brake rod
I 900 to 2
800
2nd
step
2 200 to
3 200
S
B
j
CK iXo
LL
r
I
il
L
J
1
Choke piston rod
2
Choke spring
3 Choke
piston
EF516
4 Diaphragm
cover
5 Choke
piston
lever
6 Choke valve
Fig
EF 42
Adjusting vacuum
break
EF 23
Z
ET033
Fast
idling
carn
Nut
Fast
idling
screw
Choke valve
Choke connecting
rod
Throttle
valve
Fig EF 41 Adjusting the clearance
of
throttle valve
Fast
idling
earn
1st
step
specifications
below Clearance A in
2nd
step
is
reference value
Clearance
A
mm
in
0 94
to
1 1 8
0 0370
to
0 0465
L16 to I
40 0
0457 to
0 0551
CHOKE UNLOADER
Close choke valve
completely
2 Hold choke valve by stretching
a
rubber band between choke piston
lever and
stationary part
of carburetor
3
Pull throttle lever until full open
Under this condition
adjust
clear
ance
between choke valve and carbure
tor
body
to
2 45
mm
0 096 in
by
bending
unloader tongue
Note
Make
sure
that throttle valve
opens when carburetor is
mounted
on
the vehicle
If throttle valve rails
to
open
un
loader becomes
inoperative
resulr
ing
in poor acceleration after
engine
is
started