Well my secondary float is way to high if i pull the sight plug out of it fuel rushes out and hte primary float level is too low. I tried loosening the screw and moving the screw in and out has no affect ended up ruining a gasket under the adjusting nut how do i set the float? Did i miss anything up you think cant get my car to idle down also lowest it will go is 900. The carb is a vacuum secondaries 4150 model.

 

The screw is the adjustment locking mechanism. The actual adjustment is made by turning the hex nut under the screw.

If moving that doesn't have the desired effect, you most likely have something wrong with the needle & seat.