Finding the CG?
Loopman
Start about 1/2" behing the leading edge of the bottom wing. If it wants to land fast, start moving it back until you can slow the plane down to a comfortable landing speed and still maintain solid control without being sensitive.
You will probably end up about 1" to 1 1/2" back from the lower wing leading edge, but better to start on the safe side.
Silversurfer