I purchased a 8.5 for my T4 and it was doing the same thing... it would die after about a minute or two of running.

I sent it to Novak, and in a short two weeks (short?) I had it back. Now it runs like a charm. And it's pretty robust.... I have a 23-tooth pinion on it and it flies.

The paperwork said that the software needed to be reprogramed. Eventhough I'm running NiMH packs and had the LiPo disabled, the LiPo was constantly cutting off the juice (hence the red and green flashing LEDs).