Amal and Dellorto Carburettors
The early GTs were fitted with 930 Concentric Series1 Amals, up until some time in 1973.
||This original pair of carbs are marked L 930 77 and R 930 76. Click on the highlighted numbers for a close up view.
original aircleaner hoses above are for Amal carbs with the original
clips. The large clip is attached to the solid pipe from the front airbox
connection. The hoses to the above right are original replacements but
for the Dellorto carbs. The rear hose is longer than for the Amals -
however it will fit them without problems. The image directly right
shows the adapters used on the Amals to secure the hose.
replacement gasket kit and new parts shown above includes a fibre
washer for the plastic banjo to banjo bolt connection. The original was
a much finer fit and no washer was required.
The original float needle valve was plastic, the replacement is alloy with a viton tip - a vast improvement.
The original plastic fuel banjo was opaque, the replacement is almost translucent.
When restoring the Amals invest in new needles and needle jets, the cost is minimal.
|Amal manifolds, steel front and alloy rear. No threaded hole for vacuum gauges
front Amal on the left has been fitted with the larger float tickler,
the correct example of the tickler is on the rear Amal pictured to the
The front manifold was welded steel, the rear cast alloy. Spares are
readily available as they were fitted to many British machines.
Many owners by preference fitted Dellortos of various sizes. The
Amals didn't enjoy a good reputation though some original bikes remain.
Amals actually flow more freely than an equivalent sized Dellorto.
fuel line clips are no longer on this bike as the replacement fuel line
was of a smaller outside diameter to the original Gran Tourismo. The
clamp shown on the left ( a fuel injection type ) is a good alternative.
After this time all the GTs were fitted with 30mm PHF Dellorto carburettors.
Left ( marked AS ) and right ( marked AD ) fitment as shown.
Float bowls are rounded at front and cut away at rear. Metal single
banjos. Slide retaining tops are metal. Forward small adjusting screw
is for idle mixture, rearward screw controls idle speed by holding up
inlet manifold features a 5mm threaded hole for fitting a vacuum gauge. The
sealing washer is made of aluminium. Amal inlet manifolds do not have
The GTs were fed
their air via an inefficient aircleaner box fitted with a paper
element through a restrictive convoluted plastic hose to the
carburettor. The ABS plastic construction of the airbox and their
location under the tank ensured very few survive today. Rising engine
heat and their spindly mounts gradually taking their toll. The front
aircleaner was located under the tank, the rear located on a stud under
the right side cover.
Today most owners fit pod type filters, saving weight and ensuring a cooler air flow. When
fitting an alternative aircleaner to the original the engine breather
flapper valve located in the aircleaner housing will need to be removed
||This original aircleaner, is fitted with a Fiat element, the original
equipment being unavailable for many years. It has only survived due to
the extreme care of the owner.
Click here to see the spindly mount.
36mm Dellorto Slurpers for the Raspberry Tart
These 36mm PHF
Dellortos were originally fitted to a dubious Pantah. They were
rebuilt, then the jetting game began. The pancake airfilters are RamFlo
made in Australia by Lynx Engineering and were a popular addition back
in the '70s. Various coloured foam is still available - red is my
current choice. As you can see there's no spare space on the rear
filter, the front profile is actually as narrow as the tank.
They have been fitted with early float bowls and main jet holders to give the appearance of GT Dellortos. Front manifold is Dellorto 30-36mm, the rear is 750 Sport which is straight compared to the GT 30mm Dellorto.
The original Narva Gran Tourismo fuel line is long gone, this fuel line
though is old being supplied by Gowanlocks some 15 years ago. The
fuel line clamps are original as are the Brev. Orlandi fuel taps.