What does the top control knob do? This is a Binks M1-g spray gun. The bottom knob controls fluid but the top knob doesn't seem to make a difference on anything. I
Binks Automotive | Mercari
Binks Mach 1 HVLP Spray Gun Manual
BINKS Mach 1 BBR - HVLP Spray Gun UNTESTED PARTS AS IS | eBay