Eugoogoly

To check the C of G you measure back from the front of the wing the distance it recommends in the instructions (I don't have mine to hand so can't tell you the amount) Then without fuel in the tank lift the plane up on your finger tips under the wings and check the point of balance lies within the two dimensions given. I made a couple of pencil lines on the fus.

I use two different battery packs, one weighs 50 grams more than the other. I mounted the transmitter infront of the firewall where the rear anding gear is attached and put my battery in front of that. I don't notice any difference whilst flying so it is not that critical with this model.

Nick