The HIF SU Carb6th of November, 2019
The HIF carb replaced previous types and was a significant evolution of the SU Carburettor design. The float bowl was absorbed into the base of the main body casting, the piston slides on a ball bearing type mechanism, and the layout of the various adjustment screws was completely revised.
The HIF also changed the way that the choke worked, the jet stayed in position, and an extra fuel orifice was opened by rotating a small brass valve. Later the HIF carb got an electronically controlled choke lever, see ORFCO
The smallest HIF carb was the HIF4 (later the metric version HIF38) at 1 1/2". The most commonly found is the HIF6, or later HIF44.
The HIF7 was the largest version, and quite hard to find.
HIF SU Carbs
HIF4 / HIF38 HIF6 / HIF44 HIF7 ORFCO
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