If it's possible, mine is about as light as I can get it. No added weight. I did use the Du-bro axles and I guess I got lucky, no problems. If CF gear is lighter I might try it but not sure. here's my set up.

OS 160 w/Perry VP30
Slimline pitts
16 oz tank on CG
Hitec 545's on ailerons
225's on elevator in tail
945mg on rudd pull-pull near wing
422 on throttle
6V nimh
heavy, cheap, 3-1/2" AL spinner

No added weight, CG at about 5-1/4"

joebob, where does the cooling air escape from? 2" hole isn't enough.