Sata's are good clear guns depending on the model. Your 1.4 tip may be your problem...try a 1.3 for clear. If you use a heavy bodied clear it needs to be broken up more and you can achieve this with a smaller air cap and needle. All I use in my Sata's for clear is the 1.3 tip.
I still like the old Devilbus technology for clear as well, the GTI is an excellent choice for the heavy bodied clear coats.