Different carbs use different types of chokes to get more fuel to a cold engine. Your CB1 is the same vintage as my CBR. Pulling on my choke opens an air bleed, which pressurizes the diaphram, which allows the piston/needle to rise slightly, making for a richer mixture. If your carbs work the same, those air bleeds are probably clogged.
Cleaning carbs is an easy and fun process. Taking off and putting back on the carbs is the hard part. Of course, synchronizing, and adjusting the mixture after cleaning (and adjusting the valves) gives the bike that snap. At 1000cc's, I rarely have my throttle wide-open, but I certainly like that "snap" where the bike lunges forward with a partly-open throttle.