The HD series SU Carb6th of November, 2019
The HD series SU carb are usually found in pairs, and were fitted to more premium vehicles. They had cork seals (later rubber ones) on the throttle spindle to reduce airleaks and give a smoother idle.
They always have the full square mounting flange with 4 bolt holes. The jet mechanism is completely enclosed inside the carburetor body. Usually the float bowl is fitted with an overflow pipe.
Many HD carb setups have a solenoid operated AEC (Auxiliary Enrichment Carburettor) which is effectively a very small carburetor that provides a very rich mixture.
Like H series carbs, HD carbs can have the float bowl mounted on either side of the main body. The float bowl is attached to the main body via 4 small cheeshead screws.
HD SU Carbs
If you have any photos or other information on SU Carburettors, I would love to hear from you. please send me a message: firstname.lastname@example.org