Badger 150 problem, bubbles appearing in the paint cup

while using my 150, i notice that bubble start appearing on the color cup, then the spray starts to sputter and blobs of paint start to come out of the tip. I have ensured that the brush was thoroughly clean... i check the needle and there were no abnormalities, no blockage on the paint cup...

what do you think is the problem? thanks!!!

I have a 175 and had that happen once - I believe it may be that the needle isn't thightly secured and isn't being drawn back..... That forces the airdown into the cup.

Make sure that the needle is free to move and that the cone and outside cone holder is tight but not blocking air flow.

Also check to make sure your little Teflon gasket between the head and body isn't split, nicked, cut, or squished (compressed) too much.