FUEL
SYSTEM
AIR
CLEANERS
The elements of the car buretter air cleaners must be renewed every 12,000
I ,
:.,
.vI miles (20000. km.) or.
~2
months
; more frequent changes may be necessary in
~
dusty
operatmg
conditions.
Carburetter
The
air cleaner covers and elements should only be removed when the elements
Fig. 2 are being renewed.
To
fit new elements, remove the interconnecting bracket
securing
nut
(1)
and
unscrew the air cleaner bolt s (2)
from
the mounting plate
(3). Lift off the assembly, remove the cover (5) and extract the element (4)
and
the distance pieces (6) for the air cleaner bolts .
CAR
BURETTER
S
Air pollut ion
The
carburette
r incorporates featu
reswhich
assist in reducing exhaust emissions.
control
Maladjustment or the fitting of parts
not
to the required specification may
render these features ineffective.
Lubric
ation
Unscrew the
damper
cap at the
top
of the carburet ter
and
withdraw the damper.
Fig. 2
Top
up with clean engine oil to bring the oil level 1 inch below the top of the
carburetter
damper tube.
Push
the
damper
assembly back
into
position and
screw in the cap .
Under
no circumstances shoul d heavy bodied lubric
ant
be
used.
Failure
to lubricate the piston damper ma y cause the piston to flutter and
reduce acceleration
and
have an adverse effect on exhaust emission.
Tuning
The
efficient operation of the engine
and
exhaust emission control equipment
Fig. 3 depends
not
only on correct carburetter settings but also on correct ignition
timing , contact breaker
and
spark plugs
and
valve rocker clearances.
It
is essential
that
these items are checked before adjusting the carburetters. Tuning
of
the
carburetters is confined to setting the idle and-fast idle speeds
and
the mi
xture
setting at idle speed. Adjustments should only be
und
ertaken on cars required to
conform with exhaust emission control regulations if the use of a reliable
tacho
-
meter, carburetter balance meter
and
an e
xhau
st gas analyser (CO mete r) is
available.
1. Remove the air cleaners.
2.
Top
up the carburetter piston dampers with recommended engine oil to the
correct level.
3. Check the throttle control for
corr
ect functioning.
4. Ensure
that
the mixture control (choke) will re
turn
fully, that the cable
has
T6
in. (2 mm .) free play (1) before it starts to pull on the lever and a small
clearance exists between the fast idle screws (2) and their cams.
5. Raise each carburetter lifting pin (3), release the pin
and
check that the
piston falls freely onto the bridge of the carburetter, indicated by a distinct
metallic click. Consult your Distributor/Dealer if the piston fails to fall
freely.
6. Connect a reliable tachometer.
7. Start the engine and
run
it at a fast idle speed until it attains
normal
running
tempe
rature
then
run
it for a further five minutes.
8. Increase the engine speed to 2,500 rev./min. for 30 seconds.
N
OT
E.-
Tuning
can now be commenced.
If
delay pre vents the adjustment
being completed within three minutes, increase the engine speed to 2,500 rev.jrnin.
for 30 seconds
and
then continue
tuning
. Repeat this clearing
pro
cedure at three
minute intervals 'until tuning is completed.
9. Check the idle speed (tachometer), see
'GENERAL
DATA
' and check the
carburetters for balanced air intake using a balance meter.
10.
If
the balance is
not
correct, adjust by turning the throttle adjusting screw
(4) on one of the carburetters.
Then
adjust the idle speed by turning the
throttle adjusting screw (4) on each carburetter by the same a
mou
nt unti l the
correct idle speed is obt ained. Re-check the
carbur
etter
balance.
Check the throttle shaft pin clearance and adjust if necess
ary-s
ee paragraph
17.
If a
smooth
idle at the correct speed
and
balance is
not
obta
inable ad
just
the
idle speed mixture setting as follows:
11. Stop the engine. Remove each suction chamber
and
piston , and screw the
jets (5) up until they are flush with the bridge of the ca
rbu
rett er or up as
far as possible.
Turn
down the jet adjusting
nut
(5) on each carburetter two
complete turns. Refit the pi
ston
and suction chambers
and
top
up the piston
damper
oil levels.
N
OTE.-
This operation need
not
be carried
out
if it is
known
that
the jets
are in the same relative position. '
Fig. 4
4
Fig. 3
Fig. 2
Fig. 1
CARBU RETTERS
Air poll ution
The
carburette
r incorporates features which assist in reducing exhaust emissions.
con
tro
l
Maladjustment or the fitting of parts
not
to the required specification may
render these features ineffective.
Lubricat ion Unscrew the
damper
cap at the
top
of the car
bur
etter
and
with
draw the damper.
Fig. 2
Top
up with clean engine oil to bring the oil level 1 inch below the ton of the
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