Ok.
Maybe there was dirt in the needle and seat that fell out while you took it apart and now you don't see it. Have you tried putting it together again to see if it still does it?
Have you tried to put the old needle and seat in it and see how it runs? Maybe worth a try. Maybe the new needle and seat is crap. Just because it's new doesn't mean that it's good...
And as for that part on blowing into the needle and seat.... You're hired. LOL! Gigity, gigity... :glasses7: