PSI is kinda varied. I'm using a badger cyclone and it starts out at around 50 and operates at around 30. paint is milk consistency or a bit less. How can I regulate my psi better? Without a regulator I guess.
Being your spraying with a tankless compressor you may need to thin the paint more. the longer you run the compressor the hotter it get and the lower the air pressure can be.
So I would try running a thinner mix on your paint.
Is your airbrush a siphon feed or a top feed? Did you check to see if your nozzle is clean? Try running water, if using water base paint or if your using urethanes than lacquer thinner, and see how it sprays. If that sprays out fine then try reducing your paint a little more.
To regulate the air you could get yourself an in line regulator they're only about $6 off ebay or even cheaper, ive just paid £2 GBP for one with a quick release and regulator.
hate to bud in but i think that problem can be a not so good needle bearing seal also a possible leak between the nozzle and airbrush although i am not familiar with that gun . thick paint just wont flow right . that's the problem that i had with my 150 , almost gave up on air brushing because of that. if its a screw in nozzle you might want to re seal it with bees wax if you don't have that you can probably use pipe dope i wouldn't use Teflon tape if you don't do it right it can clog the needle if its the bearing and it doesn't have an adjusting screw i saw i video on you tube about using a metric drill bit to tighten it. if you try the reduction part and regulator and that doesn't work i would ask ken what he thinks. from the first moment i had my 150 it did that tried everything the only thing that worked was another air brush. i have to send in the 150 havent got around to it