There is probably a thread on this somewhere, hopefully this will help someone. My bike had hanging idle, air screw had to be all the way in to make it not scream at idle. Figured it was an air leak so I built and used the pressure tester found on the Honda 2 stroke area of TT changed jetting inspected reeds boots, cleaned carb and a lot of other things. Finally tried a suggestion found here about the carb slide not returning all the way down, if you have this problem adjust your throttle cable to give it some slack! My bike is back to near perfection! All it took was a TINY bit of adjustment. Do yourself a favor and try this before anything else, it takes less than 10 seconds!