I just finished building my new e-flite ultimate FX, and when i ran the motor up it was wiggin' out. it ran fine down low, but once i get above 1/4 throttle, it makes this loud braping sound. at first i though somehow it was rubbing the cowl, so i took it off. ran it up and it still did it. so i made a video and here i am, asking you guys what's wrong. could it be that the motor is skipping a phase? i don't think it is because i have an inrunner that skipped phases until i fixed it and it wasn't at all like this. ill go redo all the solder connections after i upload this vid, but any help is appreciated.
e-flite park 400 outrunner
e0flite 20 amp ESC
Loong max 1300 3-cell
2 e-flite s-75's and one e-sky 8-grammer
i reaally wanted to get this plane flying today, but it's already too dark to fly.