[lippy]

You can calculate theoretical AFR changes by calculating orifice sizes and approximate what impact a change will have. I did some quick math. If you have 74 jets primary and secondary, and you simply change your PV restrictions from 70 to 76, you get a total increase in orifice area of +7.7%. If you keep air the same and put in 7.7% more fuel, this would move you, for example, from a 13.0 AFR to 12.0. *Huge* change. I know things aren't this simple, but this should give you an idea. Similarly, going from an 86 to a 94 on your secondary is a *huge* change.

Agree with jhv48 you should swap carbs and see what's up.