problem with mamba max shuting off in middle of run

i called caste and i ended up speaking with the tech for over 45 min. He was a super nice guy. and he basical said the same thing. We also talked for prob 30 min about the monster max(he said it will be out in april) He said they have all the motors there just waitng on mother boards. He mentioned. that they super nice motors and ARE hand wound. If anyone has a chance to call tech support. around 7-8am pst. do it that guy is great to talk to.
And now that im convident the esc is not bad, i just order a 9xl. :-)
anyone know around what pinion i should run?(i know i need 5mm shaft pinion)