Datsun 1968-1973 510 Owners Workshop Manual page 59

58
Chapter
3 Carburatlon and exhaust
emISSion
2
USIng
a
small
screwdrIVer
or
pointed
phers
remove
the small
E
chp and detach the
accalerator pump operating lever
from
the
top
cover
assembly
3
D sconnect
the throttle
lever
return
spring and then
the
promary to
secondary Interlock mechanIsm
return spring
4 Undo and
remove
tha four
screWl
and sprong washe and
partIally
hft away
the
top cover a
mbly Detach
the
choke
hnkage and complately
remove
the top
cover
5
D
sconnect
the
throttle
vacuum
chamber dIaphragm
rod
from
the secondary throttle lever
6 Undo
and
remove
the four
screws
and spring
washers that
secure
the carburettor flange
to
the
main
body
7
Unscrew the
promary and
secondary bore main air bleeds
and
emulSIon tubes from each
s
de of the carburettor body
8
Unscrew the
two
plugs whIch
cover
the
maIO
Jets
Carefully
remove
both
the
main
lets
9 Unscrew and
remove
the promary and secondary slow
air
bleeds
and then
the
primary
and secondary
slow running Jets
10 Undo and
remove
the
two screWS
from theaccelerator pump
bore cover
and
carefully
withdraw the
accelerator
pump
plunger
assembly
11 Turn the
carburettor
body upsIde down and
recover
the
lower
sprong
and ball valve
12 Carefully
WIthdraw the small pm from the
plunger assembly
and If necessary dIsmantle the components Take
extra care on
notln9 their locatIOns
and whIch way round each part
IS
fItted
13 Unscrew
the pump mJector securing bolt and hft away the
mlector and seahng
washers
Turn the
ceroorettor
body UPSIde
down and
remove
the
small sprong
and ball
from the mJector
bore
14 Undo and
remove
the threa
screws
that
secure
the
venturo to
the secondary bore LIft
away the
ventUri
and
gasket
15 On caroorettors fItted WIth
a
fuel
return
assembly thIS should
be removed
next
ThIS WIll
gIVe
access to the
needle valve and
seat
16
Usmg a box
spanner
unscrew
and
remove
the
needle valve
and
seat
assembly
17 Undo and
remIWe
the three float
chamber
securmg
screws
and hit away
the
cover
glass
and gasket The
spacer and
float
may now
be
removed
from
the chamber
18 Undo
and
remove
the three
screws
whIch
secure
the
secon
dary throttle vacuum chamber assembly
to
the
carburettor
maIO
body Detach the assembly from the
maIO
body and
recover
the
gasket
19 Should
It
be necessary to
dIsmantle
the
vacuum
chamber
undo and
remove
the three
screws on
the
outer cover Carefully
part the
two
halves
of the
assembly and
hft away the
dlsphragm
spring
and small check ball and
spring
20
For
carburettors
fitted to engines of
cars
with
automatIC
transmISSIon remove
the
dashpot
assembly and ItS mechanism
21 On carburettors fitted WIth a
fuel return syltem f the
Unit
was
functIonIng correctly before dlSmanthng leave well alone If
not It
should be dIsmantled for further
nvestlgatlon
It
IS
Important that
the
b metal portIon
IS
kept
Intact
22 The caroorettor top
cover
may be dIsmantled If the choke
valve
and shaft require attentIon
Mark the relatIve position
of
the choke valve and
cover to enSUre conrect
reassembly
23
USing a small file remove the
peen 109 from
the ends of
the
choke valve retaIning
screws
24 DIsconnect the
hnkage from
the end of the
choke shaft
25
Usmg
a
small screwdrIVer undo and
remove
the
two
choke
valve
securing
screws
W thdraw
the
choke valve from
the
shaft
26 Withdraw
the
choke valve shaft from
the
cover
27 Should It
be necessary to
servIce
the flange fIrst
screw out
and
remOl ll
the d1e mIxture adJultment
screw
and spring
28 Remove the throttle adjusting
screw
and
spring
29 Mark the relatove posItIOnS
of the prunary and
secondary
throttle valves and their
respectIve
bores
30
USing
a
small file
rem
the
peening from
the ends of the
throttle plate
securing
screws
31 WIthdraw both throttle
valves and then
WIthdraw
the throttle
shafts from the
flange
32 Undo
and
remove
the
throttle lever and assembly retamlng
lH
W
O 3
F
g 3 10
Removal
of
accelerator
pump
Sac 10
FIG 311
COMPONENTS
OF
ACCELERATOR PUMP
1 Pump
In ector
6 Piston return sprmg
2 H ght 7
Clip
3
Outlet
valve
8 Stramer
4 Piston 9 Inler valve
5
Damper
spnng
1
O
Oe
@e
o
0
e
e
Fog
3 12
Float chamber components See 101
1
8
f
f
8
0
i
e
0
O
0
0 0
FIg
313 Removal of emulSIon tubes See 10l