Fuel air mix screw. confirmation of a theory...

I put pod filters on my LTD400. Did a rejet. Replaced all sorts of other crap and she starts fine. However she will only idle with choke fully on. So out of curiosity I checked the mix screws on the carbs. On one side they were screwed out 6 and a half turns, on the other 8 and a half. I screwed them in and set 'em at 2 and a quarter turns each but my gas tank is empty. Can I assume the previous owner had this set for waaaaay too much air? How dramatic is an extra half dozen turns on that screw? Advice would be appreciated.