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The chokes on the Webbers are not chokes in the normal sense that close a butterfly and thereby suck more fuel, but are in fact "enrichers" that supply more fuel by another method. Your carbs may have had some parts of the enrichment circuit removed or the gaskets may be leaking and thereby not functioning properly. If you have a choke cable connected to both carbs and it does not help the cold start, I would suggest you get a Webber carb book and study the parts in the enrichment circuit. Also you can see if the cable is attached at the proper opening of the enricher levers. Hope this helps,...
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