actually, I think you've got it backwards. My plans show the CG between 5" to 5 1/2" from the LEADING edge of the wing, as measured right along the fuse/wing union. That's where I balanced mine and it was perfect. I used an OS 91FS and it was actually nose heavy. Most people have the same experience. I simply moved the battery pack much further aft than the plans showed to get the correct CG. I didn't add any incremental weight to get the plane to balance right on the "plan" CG. If you don't have a GP plane balancer, borrow one. It works great. You might also want to check a number of the threads here on RCU about this plane before you fly it. If you're flying off grass, you'll want to shim the landing gear forward to prevent noseover. Also, make sure you have the revised elevator throws (check the GP website). This plane is very pitch sensitive and you'll need only very small elevator throws. Have fun,.... Steve