One should set the high speed needle first, lean it out until peak RPM is a cheived, then richen it up a 1/4 turn (that is turn the needle out a 1/4 from peak RPM). The check idle transition. If the engine stubles, it is rich and adjust the low speed needle (or screw) 1/8 turn in ward. Make this adjustment with the engine off (to save fingers, etc.). Start her up and test transition again. Have patience, you will eventualy reach the sweet spot and your engine will give you great performance.

Holding an airplane up tests to see if the rich setting is enough. If the engine quits, the high speed needle is set too lean. There is also the pinch test. Do a search on "pinch" and you will find a lot of information on that test.

Remember, slow process and have patience.

Cheers,

Chip