Twin 40 - identify holes

[paul james]

I've taken my air trumpets and the backing plate for my air filter off my Sport twin40's today for the first time. And its exposed a hole on each of the carbs, that I have no idea what they are for. Are these holes supposed to be covered? as they were with my air filters backing plate.

http://homepage.ntlworld.com/paul.james21/SDC10297.jpg

[paul james]

I just looked at the ITG air filter metal back plate, and there are two holes in it for the holes in the carbs pointed out above. So they are getting filtered air. But does anyone know what these holes are for?

I've got some sock filters that go over the trumpets in the post, I was going to use instead of my current filter since they will fit in the engine bay better. But I guess they wont cover these holes very securely.