Opening the needle valve 4-5 turns from closed will ensure you have a good rich starting point. Here are some good instructions for breaking in all ABC/AAC engines. It's worth the time to follow these directions, as an engine is an investment and you want it to last for as long as possible.

http://www.jettengineering.com/ (look under the instructions/tech section for engine break-in).

Once you have it broken in, tune it for performance using your flight propeller (not the breakin prop). Use a tach and slowly lean the needle valve until you get max rpm and it barely starts to fall off. IMMEDIATELY richen it up (1/2 turn) and let the motor cool off. Once cool, start it up, slowly lean to max rpm and then immediately back it down about 800-1000 rpm. This will allow the engine to unload in the air without going lean. Once you have it set 800-1000 rpm down, do the "pinch test". Quickly pinch the fuel line at the carb - you should hear a noticeable increase in rpm. If you don't richen it up a bit more.

Good luck!