cogging on mmm

[luvsrc]

I'm using my MMM v2 on my losi type r with a team orion brushless stock motor which i geared it high but it cogs whenever it starts to roll any suggestions to solve this , i really need it in high gearing to keep up with the stock competition or i just go ahead and buy a sensored speed controller like the one that is coming like this http://www.redrc.net/2008/10/lrp-spx...stockspec-esc/