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.

The 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.

The 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

The 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 right.
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.
The original 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 the slide.
The Dellorto 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 these fittings.

Air Cleaners

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 and relocated.
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.

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