Don't know if this will help, but there's a little trick that will let you know if the float level is where you set it, when the car is running. With the sight glass tube attached (or with the lid/float assembly removed, however you set it), get a little plastic straw from can of carb cleaner or something, pull off the vent hoses, and put the straw through the vent fitting. It will rest lightly on top of the float. Mark it (I measured 5mm above the vent) with a marker or scotch tape, etc. When the car is running, measure it again. It should be easy to see where the floats are when it's running.