The Facet is too high a pressure for your carbs.
...............
The correct pump for your carbs is;-

Huco low pressure 12v fuel pump 133010
Description
12 V Positive or negative earth fuel pump made in Germany.
Supplied with Unions & Mounting Bracket.
Suitable for use in standard road, Fast Road, Rally and Race cars with engines producing up to approx. 160 BHP.
Specification:-
Pressure 2.1 PSI
Flow 27.5 Gallons per Hour (125 Litres per Hour)
Union fuel pipe size 5/16 inch / 8mm
This pump is a suction type and designed to be fitted in the engine bay of the vehicle.
This pump is ideal for use with Dellorto or Weber carburettors, the low pressure eliminates the need for a pressure regulator.
Manufacturers part number 133010
Where can you get it ;--
No the local agent tries to sell you the 4 PSI pump under the explanation that that is the only low pressure pump HUCO make but thats Bull

You can import it from;-
https://www.dellorto.co.uk/shop/car-acc ... mp-133010/
Herman