I'm unclear about something. First you say that the connectors that you got are smaller than the connectors on the MM, but you also said that you were running the setup and then you make reference to hardwiring.

How did you make the connections to get it running when you saw the cogging? A bad connection like a loose on or a bad solder joint will definitely introduce some pretty horrible cogging.

A brushless motor will pull as many amps as it needs to meet the demands that you put on it. Although I may be wrong, for this reason, I run my MMs at the highest start power setting with the timing on the lowest setting. My systems run very well like this and as cool as a Feigao can run.

I would look to the connections first and if you haven't hardwired yet, go ahead and do that, unless you have some good connectors. I'd say that the 4mm connectors and just barely adequate for a 1/8 scale application.