Conversion Jet-Turboprop

HiI'm trying to make a jet airmodel -> turboprop airmodel conversion for FS2k2 but I got some odd results. As soon as the plane gets airborne, the pitch angle starts to jump up and down very hard. The same results are attained by slewing the plane into the air.Looking to the plane in spot view, I've noticed that control surfaces (ailerons/elevators) are spinning very fast around their axes. Seconds after that, I lose control of the plane and it crashes (aircraft overstress). Other symptom is that G's indication via shift-z is completely crazy. The indication was -._G's and fade-out/red-vision effects appear just before it crashes.I've look into the entire aircraft.cfg and compared it to the original King 350 aircraft.cfg and i was not able to reach any conclusions about the problem. Then compared the .air file himself to King 350 via AirED and again, didn't have any ideas to solve the problems.Since I've never seem nothing like this and it is my first try converting a jet model to a true turboprop model, I will be very grateful if someone point me to the right direction or say what should I do to get rid of such behavior.Many tnx,Melo