One thing that I can tell you is CG is VERY important. I've known guys who get an RTF or an ARF and think there is no reason to bother checking it. Believe me, if it is too far back, you'll crash the plane. I know from personal experience. I've also known people to get rid of a poor flying plane that might have been made better by setting the CG correctly. Even if you didn't put the plane together, chances are you know who manufactured the kit or ARF. You can usually download manuals from company web sites. Also, whatever plane you might have, somebody else on here likely has one too and can help with the CG. Here's a good link:http://www.495thsquadron.org/TechTalk-CG.htm For most planes though you can usually just locate the CG on the wing and use your fingertips to lift the plane up. Another often overlooked factor is lateral balance. If one side of the plane is heavier that the other, flight will be affected. A little time spent doing a lateral balance adjustment can make a good plane even better. Hope this helps.