Keihin bike carb quest

[trackerjack]

Hi to those with bike carb knowledge.

I am in the process of fitting these carbs to my CVH engined Quantum.
http://s139.photobucket.com/user/dolly-sprint/medi...


http://s139.photobucket.com/user/dolly-sprint/medi...


The question I have is "Why has the previous owner of these carbs blocked the hole shown?"
I realise that I will have some work still to do to get them running well but I have been there before.