I don't know if you figured out you problem out yet... I had the same problem...
Once I got above the 75% throttle mark, mine died out as well. Here is a link for the youtube channel....
http://www.youtube.com/watch?v=PX9UgHfg_NM


you have to 0 set the pitch... the blades would not have enough speed, once the collective hits the motor struggles and esc cuts power to minimize damage.
hope that helps you!