Scooterotica

For the atomiser the higher the number the richer.

For the slide the higher the number the leaner.

Needles are a whole other thing. It's all to do with the length of the taper and the diameter of the tip.

Some good info' about PHBH carbs on here:-

http://www.bristollambretta.com/mixtureadjustment.htm

...and jetting on here:-

http://www.smellofdeath.com/lloydy/jetting.htm