Welcome, a couple guys used to run the single intake and carb but it wasn't popular due to loss of power. With the simplicity of the Mikuni carbs it doesn't make sense to convert. Here is a tiny bit of info from the wKB .  I clicked the link and it looks like the KJS Forum is pretty much dead.   "A rather expensive option to convert the V Star 1100 to a single carb though the use of a specially developed manifold and a carb like the Mikuni HS40. For further information regarding the set up and operation please visit the KJS Owners Group Forum". KJS Owners Group (delphiforums.com)