The proper setting will differ from person to person in different climates. Set the high speed so it runs the fastest without the rpm sagging at WOT. Once you hear it say or cut out, open the main needle 1/8-1/4 turn. It should still run smooth at WOT albeit a tiny bit slower than totally peaked.
Set the low speed so it will idle nice and low for 15 seconds and throttle up without a hiccup. At the 20-25 second mark, it should be a little loaded up and burble a little when you punch it. The idle gap is critical for getting proper settings. The gap should be in the 0.5-0.7mm range. If you adjust the idle gap, you will need to reset the low speed mixture.