Did you have to solder new connections? Had some isseus with boat that only went full throttle for 20sec, then cut off. I discovered it was due bad connections because i used wrong type of solderingflux... Try to figure that out!
something is def off with the setup, should be whipping hard for ever no issues. either batts or ESC programming be my first guess. Did you see my Zonda running on that ESC? +80mph within ft buoys?!