I started this thread and in a subsequent response to another thread said that just plugging the one line did not work. You need to disconnect the valve from the air box and plug both sides in order to render the system inoperative. The reasons to do this as opposed to taking everything off are:
1. Ease of completing the task.
2. Being able to re-assemble the system if you have to satisfy future govt. mandates.
I live in the peoples republic of California
and cannot predict what the California Air Resources Board may mandate re. emissions requirements for the resale of motorcycles.
Plus it is a lot of work to take everything off, plug etc when you can do it in about 5 minutes if you go the alternative route mentioned.