Pulled the carb back off last night, took it apart and inspected.
My PZ-30 Keihin clone carb uses normal looking Keihin jets.
The main jet is a 102 and closest fits a #60 drill bit which is .040" which is 1.016mm... or 102. My slow/pilot jet is a 38 and the #79 (.0145"/.368mm) drill bit fit and the #78 (.016"/.406mm) was easy to twist through. Then I drilled the #77 (.018"/.457) through in my attempt to open it up a bit. I'm thinking I may have opened it up a little too much... now being ~45 slow jet.
So... I'm thinking I'm rich on the bottom (jet big now) while being still lean on the top (102 jet)... which would explain why the needle was full up (lowest c-clip slot). I'm going to put the needle back to that position and turn in the mixture screw some (maybe 1/2 turn out) and see what that yields me.
I ordered a PZ-30 rebuild kit that comes with a 110 main (should be ideal) and another 38 pilot (might need tweaking)... so I lots of carb tuning to come.
Checked the exhaust and it is free and clear... outta be with so few miles on the bike. And the petcock is flowing plenty in both on and res... so good there.
Cheers!