I've recently been trying to perform waterfalls and elevators with my aeroworks 90-120 yak. My waterfalls aren't very tight and my elevators don't drop straight down. My cg is slightly tailheavy and my 3d rates on my elevator control surface is everything i can get. My engine idles around 2100 rpm with a 17x6 prop. Do I have a cg problem? Should I be more tail heavy or nose heavy for these maneuvers?