your power wires (wires going from battery to ESC) are way too long....you want them as short as possible...when they are longer this increases resistance. And as Sleebus said telling us your setup would help...your gearing or motor KV could be too high for your batteries......get the Mamba on there the MGM is just adding alo of extra weight for no reason....a Castlelink will run $24

http://www.rc-monster.com/proddetail...phx-lnk&cat=21