SU in! Needs fine tuning but it’s already much better than before. Here the first cold start. First crank and the engine was purring like a kitten.
https://youtube.com/shorts/oM_ro7AdZ...juGQIHnPcVwKzG

Excellent!

Advise needed!
Getting around the SU carburator, to make fine adjustments.
However I have realised there is no need to pull the choke. Engine starts first crank, idle high at 1300/1400 rpm and settles in a minute or two by itself.
It’s cold outside, around zero Celsius.
If I pull the choke Keeps idling at 1300/1400 rpm.
Any idea what’s wrong? Or what have I done wrong when installing? It really was a straight swop.

Quick update. All went well with the carb swop. Engine runs better. However the more efficient carb ended the life the fuel pump. Fuel pump replaced ( I have tried an electric pump replacement but after shutting the engine it would still pump little fuel which was detrimental to the next engine start…).
I have also adjusted the valves to original spec 0.45 and retarded spark ignition.
It now runs like never before. If I only knew this before…
I would drive it no bother on a 3/4k miles trip. I am actually thinking of driving it to Sweden…

What a great restoration, hats off to you. Love the colour also.

You HAVE to. You KNOW you want to. So, in the words of the Nike advert: Just do it!