Ok I would say your first bet is to have the carb dipped in a cleaner its got white corrosion around the top of the emulsion tubes and I suspect in various other drillings you cant see that sure is one dirty carb, Not sure you can buy it here but Gunk do gallons of carb cleaner where you suspend the whole thing in it. I have used gun wash thinners with success in the past.
I would soak it for at least several hours and recheck it should come out like new alloy, the spray carb cleaners wont be up to the job.
below I have put a image of the weber in parts and the key to whats what.
when clean blow through all the drillings/jet holes with a air line and rebuild with a new kit which is available on ebay http://www.ebay.co.u...=item257c6f4049
or here Fast road cars http://www.fastroadcars.co.uk/shop/index.php or Webcon http://www.webcon.co.uk/