PHBH idle

excuse my ignorance, but can someone help me?? on the PHBH carbs the air screw is on the engine side of the slide… so that means that as you screw it out it lets more air into to mix making thing leaner… right?? screw it in and it makes it richer… well how come on my bike when I screw it right in, the engine picks up speed as if it were leaner??? just to add some back ground I have a 55 idle 30slide the motors a malossi 166 reed, and simonini pipe. also I have to turn the idle screw right in other wise it idles suuupppppeeeerrr slow and bumpy… any ideas??
thanks

30 slide sounds low to me…but what do I know?

try this:

http://www.owners.heskethmotorcycles.co.uk/technical/dellorto%20PHF%20carb/intro.htm