I have a F9F -8 Cougar from Hobby King. 880mm wing, 1000mm length. I install a 4000mah 4s battery and check the CG which is 80mm back from the leadinf edge. Turns out very nose heavy, any where it should be?. Once in the air it can only br flown with full up elevator, making it difficult to land.

Thanks M Cannata