xplaneguy, Love the covering job! I built one a couple years ago, and added the same motor and esc. I bet you needed the large battery to get the cog right. Im using a 11.1 volt 3200mha lipo and a larger prop. Mine feels a little under powered, but these are not speed demons. Mine will float forever if I find a good thermal. I liked the model so well, that I built the little sister, the Peice o cake. They are so relaxing to fly.