Don this is Joey if you still have problems let me know, I can get it fixed up for you. I've been flying (and cussing) a blade 400 for about 4 years now. I can take them apart with my eyes closed.
Your problem sounds like a low voltage cut off. Make sure you have a 3s lipo, the esc is set to 3s cutoff. If that is ok then the lipo is bad or the head is binding up and causing the amps to surge.

I have a spare stock ESC around here somewhere but just about any esc is better than the stock one.

Joey