No problem. I had that happen to me once and now if I run into it it's the first thing I do. It's amazing just how many I have fixed like that, especially Evolution engines. There is usually a small hole right at the needle valve and since this is usually a clear line it's very hard to see it.

He did mention that the bubbles were in the line between the carb and needle valve so it was the first thing I thought off. Assuming the line from the tank to the needle valve has no bubbles in it I would replace the line first then do everything else that everyone else suggested.