MG MGA Twin Cam Workshop Manual page 80

THE FUEL SYSTEM
D
Fig. D.IO
With the mixture control right home there should be a
small clearance between the adjusting screw (arrowed)
and the cam
beneath
it
th_e throttle is fully ciosed and lift the piston
i
in. (1 3 mm.)
to put it out of action. Repeat the adjustment operations
on the front carburetter.
When both carburetters are correctly adj usted for
mixture set the throttle adjustment screw of each to
give the required slow running. Adjust the link
~tw~n
the mixture levers so that each lever is moved the same
amount when the mixture control is used.
Slo" flllllliag aDd synchronization
Tum the throttle adj ustment screw of each carburetter
to give a fast idling speed, taking care to turn each screw
the same amount. Next unscrew each throttle lever
~djustment
screw an equal amount, a fraction of a tum
at a time, until the desired slow-running speed is obtained.
Accuracy of syochroruntion can be checked by
listening at each carburetter air intake in turn through
. a length of rubber tubing and noticing if the noise
produced by the incoming air is the same at both. Any
\'ariatioo in the intensity of the sound indicates that one
throttle is set more widely open than the other.
, When the same intensity of sound is given by both
carburetters the coupling shaft elip should be tightened
to ensure that the throttles work in urtison.
Note that a small peg in one lever fits loosely in a hole
in the other lever to form a connection between tbe two
spindles. When tightening the
lev~r
clamping nut make
certain that the peg is located centrally in the hole when
both throttles are closed.
Since the delivery characteristics wben both car·
burcuers are working together vary somewhat from
those existing when each is working separately, it will
be necessary to check again for correctness of mixtnre
strength by lifting eac-n piston in turn as indicated in
'Adj~ing
the
jets' and adjusting as necessary.
Section 0.11
REMOVING AND REPLACING THE
CARBURETI'ERS
Disconnect the fuel supply pipe and the flexible
connecting pipe at the rear carburcttcr
UQion.
Remove tbe two set screws and spring washers securing
each air cleaner and remove the air cleaners. Remove the
split pin and fiat washer and release the mixture cable and
clevis pin from the mixture control linkage, and release
the mixture outer cable a butment complete with bracket.
Remove the split pin from
the
jet lever interconnecting ·
link to separate the two jet levers. Detach the throttle
return spring and release the · t hrottle cable.
Unscrew the union out . .and disconnect the igrution
vacuum control pipe from the front carburetter.
Remove the out and flat waSher on top of each floai-
chamber to release the vent pipes.
Remove the four nuts, spring washers, and plain
washers securing each carburetter Bange and "ithdraw
the carburetters. The throttle cable a butment bracket
and throttle return spring bracket will also be withdrawn.
Replacement is a reversal of the above instructions.
Do not attempt to remove file earburetters and !DdiiCtion
manHold as an assembly. Tbe induction manifold is secured
by
two studs inside tbe intak~aDd cannot
be
released
until
~ carburetters are remo••"lf: ·
' Fii,:
.D.ll
The
carburetttr filters should be r<moved and cleaned
with
a
brush
every
6,000 milts (10000 km.)
D.ll