Just found it what it is. Visit local hobby shop and we had a play with it, front linkage that comes of throttle servo horn is slight bent (no idea how) and intermittently sticking, need to pull it out and try to straighten.
Certainly not the best designed system out there, thats what you get when you buy a cheap buggy though.
Do you think it would still work if i disconnected the front brake altogether? Im not racing this so i dont care if outhers can outbrake me. Wondering if it will snap sideways if its rear brakes only.