Motorcycle Repair: jetting, screw out, hyper charger

Question
I have a 2000 Sportster. I have stock mufflers, but the verticle baffles have been removed( the horizontal one still remains). I installed a hyper charger and put a #45 slow jet and a 170 main jet. It was fine for the 1st week, but now I've checked the plugs again and they are a little chalky looking. Do I need to go up in jet size? Also, when installing it, I understand I was to turn the 'mixture screw' out. I have the shop manuel for my bike, but I have no idea where this 'mixture screw' is. Does it go by another name?

Answer
The mixture screw is located under the plug at the bottom of the carb. The plug has  to be drilled and pulled out and the mixture screw is under it.
If your plugs are white you to go up a jet size on the intermediate jet
Good luck and happy riding
Mike