Quentin, please go ahead! Thanks for your help already, but I need all the additional information I can get. It runs, but it's not too drivable. I'm planning to get it all set up properly fairly soon (with Husky's help), but any simple tweaks I can do in the meantime will help hugely.
One problem is that it's jetted way lean, but you can richen it up sucessfully using the cold-start circuit (an enrichment valve in place of a choke). That works fine when you're driving (as you can see), but there's far too much fuel on idle. Easy you might think - just push the 'choke' in when idling. However, setting the idle speed mixture correctly on the choke makes it idle at 2500-3000 rpm. Unlike a normal carb, you don't get a nice idle speed screw, and even if there is, there isn't a nice ADDHE manual you can look it up in! There's got to be a way to adjust that, but I'm a bit busy to look into it right now. The car is again capable of getting me to the shops and back, and that's good enough for the moment!
Anyway, to the vid...2.5mb
http://www.foggyjames.co.uk/inbox/carbnoise.wmv
(Give it ~30 mins to upload...damn broken internet connection! Dial-up is literally faster!)
How loud it is in reality is hard to grasp from that, but you get the idea. The nice thing is that they're just as quiet as the original on cruise, but boot it and....enjoy
cheers
James