It is a new carb. The engine had a 40 year old Weber 32 ADF which had a hot water choke system (that didn't work) plus other inlet/outlets that had been blanked off (fuel return, etc.). I spoke with Guy Croft and he recommended this carburettor but re-jetted for the Fiat 2 ltr engine, which has been done. The engine runs fine, I was just curious as to what the pipe was for.
Maybe I'll try the vacuum test on the opening with the engine running. It could have been blanked off by the supplier as he did the re-jetting and knew which engine it was going to be used on.
