Laucel is your aiplane a twin or a single ? mine is a twin and the CG as marked on the fuse was about an inch too far forward. I balanced mine on the mark and then added 4OZ of lead too the nose and I needed full down trim to hold level flight I only went one lap and put it down straight away, needed more weight in the nose and I already had four batteries up front.. I started off with level elevators at take off and the Yak just took off by itself without any input of elevator and immediately needed down trim lots of it then the rain came and that ended the day PM me if you want more info ..Malcolm