Just when I promised myself I would never pester you guys by making another post, here I am doing it... 
Background: I've a pilot's license (since 1970). I've attended many aerobatic airshows and understand what they are doing in the maneuvers. I have flown RC airplanes since 1970. I participated in RC "Pattern" contests (aerobatic flying). I can do knife edge flight with an aerobatic RC airplane (of which I've had many), or in Aerofly RC7.
Issue: When I try to do knife-edge flight with the Jungmeister or Extra 330 or Pitts S2, the nose drops below the horizon even with full throttle and full rudder. I can't hold the nose up for level knife-edge flight.
Suggestions?