esc help

[sickboyboone]

I have 2 mad torqe crawlers bone stock electronics. both have started barely moving in reverse. im thinking its the esc but not sure yet have to test tonight. if I need new ones what is a good reliable one to use? I dont want to run duals and im not interested in dig as of yet they are mainly used to crawl around with my kids in the yard. I may replace motors later and the servo when it breaks. I may switch to a lipo battery and give my two bartteries to my kids who also just got their crawlers. the two with problems are me and my buddies, weve had them about a month. any help would be awesome