It works perfectly fine with the MGM on there, Its just big and heavy.

w/ the mamba:
It will cog at a standstill and not move at all, but if I give it a little push so its rolling 4 or 5mph and gently accelerate it works and it fine once the rpms go up.

Setup is 10 cell IB1400s on stock gearing. Castle 5400 kv motor. MGM 22418 (the mamba will go back in once I get a chance to look at the settings)