skyblue. All my flying has been with li-polys so i can,t say for sure what your problem is but you usually have to try different prop's to get the best performance for a particular airplane.I do have a Hacker brushless in a Electro Streak and it is very impressive.I have dabled in electric,s for many year's but the li-poly's have re generated my interest.You get longer flight times and they weigh much less than ni-cad's or hydrites.and with a dedicated charger and some caution in charging you can have a ball. Tim.