You need a gasket to seal the well this will give you the straw effect your not getting at this point . Just by increasing the inside diameter of the tube will cause the mod to auto feed. The mod is cool but to be honest how hard is it to push the bottle

I called the first 20 mini mods back because they were auto feeding .I never told anybody that was the reason . I had to reduce the inside diameter of the feed tube .This auto fed with the cap on tight no holes in the bottle. I beleive the inside diameter was 1/8 or 3 /32