yep thats one of the first thing one should do if your getting O/P, run to the regulator and crank it up.
Jay D.

I read in your post that you are overlapping passes by one inch. Typically there should be about 50% overlap. As others have stated, it might help to thin your clear a touch with a little reducer. Also agree with upping your air pressure a bit, and by making these minor adjustments it'll look great. I would sand down your existing orange peel to flatten it and then spray one more coat with these adjustments.