Why do you ask?
Have you tuned the rest of the carb?
Honestly, if you have to ask which way to turn the needles to richen it then you probably need a tutorial on tuning as well.
Not trying to bash or flame you but if you just start tweaking needles you'll be in for a lot of tuning trouble.
I don't know what engine you have but here's a link to Traxxas tuning guide. It's a pretty well written guide with photos and should help you a lot. Don't worry if you don't have a Traxxas engine, all nitro engines tune pretty much the same.
http://www.traxxas.com/support/index...l&cat=34&id=92
There are also a couple of tuning videos on YouTube that use a Savage 25 that are very helpful.

Good Luck