They come out tail heavy. One I built used the Saito 100 and took a lot of work to get the CG set as shown. I don't recall but I think I had to add lead. Last one I built had a .75 two stroke and needed lead in the nose. I try to never add weight to any of my builds but sometimes it is required even with all the gear placed forward of the CG. Fantastic plane even with the added weight though.