Barnburner
Coast to Coast
When you say "close the choke" are you referring to engaging the choke (i.e., moving the choke lever so that the carb's airway is partially blocked)? A bike should need some choke when starting cold, but it shouldn't need it always engaged to run. If after it starts you still need to restrict the airway to keep it running then it is possibly lean. Definitely keep the airboxes on there. Running the carbs straight open it's never going to run right. However, there are so many other things that could be causing it not to run. I'm too lazy to look back in this thread, but did you adjust the valves, gap the points, and set the timing?