HEy all I was out running the Big Rock today and it just stopped moving forward or back. steering still worked but no movement. took motor assembly apart , found nothing wrong. diffs good . re assembled the power assembly and re adjusted slipper clutch with new spring bolt and locitited and roll adjusted slipper . still no movement. did a rebind and it worked. took it out ran around the parking lot. worked good for about ten minutes and stopped moving again. flicked the trigger a few times forward / reverse / brake and it took off. did that a few times , then quit all together again. ESC light blinking green four times and repeats the flashes over and over. any ideas ?