The older firmware for the Mamba Monster is much better than the newer firmware IMO. I updated mine and I had the same problem with cogging. So I want back to 1.22 (I think) and it is much smoother. If I were you I would just ditch the Losi ecs once you get it back from repair. The owner of my LHS had nothing but problems with his (until he replaced it with a MMM) and most other people that have them also give them a thumbs down. Stick with the MMM its a much better and more reliable esc that will never let you down.