Yes PCV.
So backing the screw out to the last thread - the screw wobbles, and I figure is likely to full out with normal driving - is where she runs best, but the plugs still carbon up. it's almost as if i had another couple of turns everything would be right.
As I have an extra mixture screw, I'm tempted to file it back a bit and see what happens.
But - Joe has me thinking I might have missed something.
As the mixture and idle affect each other, where the mixture might be about correct, the initial setting for the idle is already too low perhaps.
So maybe start with a higher idle setting then bring it down after ballparking the mixture 1-1/2 turns out.
A bit uncomfortable playing around with extended idle periods on a brand new engine.
