I don't think I saw anywhere in his post where he said he was constantly flying a full throttle, he just wanted to know why it didn't want to roll at full throttle. I have the Kadet SR ARF with an OS 70 fourstroke on it. I fly around mostly at 1/4 throttle or less, if I want to play a little I will throttle up and it will roll and fly inverted with no problems (at 1/4 throttle or at high speed). Granted it takes some rudder and down elevator to control the rolls and some down pressure on the stick to fly inverted. I only have futaba 3001 standard servos in mine also. The only difference in the 3004 & 3001 is number of ball bearings they should have the same amount of torque so the should be enough servo. The Arf version does not have as much dihedral as the kit version so it will roll and fly inverted better but don't expect it to do very pretty rolls thats not what it was designed for. It is a touch and go animal like tcrafty said, If you want to be great at takeoffs and landings this is the plane to learn with. If the plane is set up right you can almost takeoff and land using just the throttle and hardly any elevator at all. Don't get into a habit of firewalling the throttle to take off or pulling the throttle all the way back and gliding in to land. Learning to use the throttle properly and learning rudder control will pay off in helping to fly other type airplanes and flying aerobatics. With that being said if you wanted a more aerobatic trainer you need to get something with a semi symmetrical wing. Didn't mean to be so long winded & hope this helps
fossil