I have a IWATA HP-CS that has worked perfectly up to now. I completly strip clean it after every session. But this session I am getting blowback bubbles in the paint cup. The barrel is not split, the nosecones are all handtight and the air passage as far as I can tell is clean also. The rubber o-ring is clean at the base of the nose of the main body. The needle chuck is tight also. The paint is Testors MM II enamels. The paint is mixed with a Badger mixer and @ 50/50 basepaint and white, then thinned w/thinner to now almost a water consistency and no luck. I even tried straight thinner and no luck there either.
Obewan, your my only hope, the DEATHSTAR is looming close, I feel it in the force.