Datsun 1200 - Page 38

5 Fuel
SY6tem
TOP COVER
MAIN
BODY
POWER VALVE
SECONOARY
MAIN
AIR 8 O
SECQNOARY
SLOW
JET
t
i
PRIMARY
SlOW JET
C
O
to J
SECONOARV
SLOW AIR OLEED
It
POWER VALVE PISTON
PRIMARY
SLOW AIR BLEED
Internal View of Carburettor
Top
Cover and Main
Body
Assemblies
1200 Series
2 Mark the choke
valve in relation to the cover
to
facilitate
correct
assembly
3
Using
a
small
me
remove the peening
from
the
ends of
the
choke valve
retaining
screws
4
With
a suitable
screwdriver remove
the two choke
valve
retaining
screws
and
withdraw
the
choke valve
5 Remove
the choke
valve shaft from
the
cover
6
Lay a
straight
edge
across the
gasket
face
of the
cover to check for
warpage
File the
cover
gasket
face back
to
a true
condi
lion if ex cessive
warpage
is eviden t
7
Reassemble
by carrying
out
the
dismantling
procedure
in reverse with
attention
given
to the
foBowing
points
Check
the choke
valve
for
proper
operation
Instal the
two
new choke valve
retaining
screws
and
peen
the ends
of
the screws
to ensure that
they
will not work
loose
and
fall
into the inlet manifold
TO
SERVICE FLANGE
I
Screw out
the
idle
adjusting
screw and
spring
2 Remove the throttle
adjusting
Screw
and
spring
3 Check the
primary
and
secondary
throttle valve
shafts for wear
in the
flange body
If wear is
not
evident
then do not dismantle
the
shaft assemblies
4 Mark
the
primary
and secondary
throttle
valves in
conjunction
with
their
respective
bores
File the
peening
away
from the ends of
the
throttle
plate
retaining
screws
and remove
the screws
5 Withdraw both throttle valves
disconnect the
primary
to secondary connecting
link and
then
remove
both
throttle shafts from
the
flange
6
If
necessary
unscrew the
retaining
nut
and remove
the throttle
lever
etc
from the end
of
the
primary
throttle
shaft
Note how
components
a
re situa
ted before
dismantling
to ensure correct
assembly
7
Inspect
the
flange
for cracks
and
the
gasket
surfaces for
nicks or
burrs
S
Lay
a
straight edge
across the
gasket
surfaces and
check for
warping
9
Check the
seating
surface and
the
thread
of the idle
adjusting
screw
for
damage
IO
Place both
primary
and
secondary
throttle shafts
into their
respective
bores
in
the
flange
and check for
excessive
clearance Renew
the shafts or
flange
as found
necessary
I
I Assemble the
flange
in
the reverse
order of
dismantling
with attention
given
to the
following
Adjust
the
primary
and
secondary
throttle valves to
close
fully
Check
both
primary
and
secondary
throttle valve and
shafts for
smooth
operation
and
peen
over
the
ends of
the
valve
retaining
screws
Turn the idle
adjusting
screw
and
spring
in
gently
with
the
fingers
until
it
just
seats and then
back
it off
appruximately
3 turns
Screw
the
throttle
adjusting
screw
in two
or
three
turns
NOTE
The
abovementioned
adjustments
on
the rhraule
and idle screw
are olllv
preliminarY adjustments Engine
idle mixture
and
speed
must be
adjusted
correct v
with the
engine
at
operating temperature
See
adjustment
section
for
procedure
TO
ASSEMBLE
I Assemble the
flange
with a
new gasket
onto
the
carburettor
main
body
and instal
and
tighten
the three
retaining
screws
2
Assemble the
top
cover to
the
main body
with a
new
gasket
and instal and
tighten
the five
retaining
screWS
38
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