I think it's the right one. It's the Novak HV4.5 motor that NOvak made for the e-maxx. I got it geared at what Novak has recommended but that's with thier esc. If I can't get the software improve it. I'll gear it down a bit. The MM is the only esc I have for them at this time. Both my HV esc have been sent back to Novak for replacement. The mm is actaully doing a great job with the motor. It's seems to be running cooler and with longer run times then when I have the Novak HV esc in it. I found the manual for the mm so I got a better idea of what to try.
Oh, your probably thinking I'm using the velocity 4.5 motor that comes in a 540 can. Instead of the High Velocity 4.5 motor. The HV4.5 and 6.5 are 550's.
with the software update , i still had some problems, although i think mine was caused by gearing, i spent the better part of an afternoon and got it to start ok in my truggy, but a smaller pinion would have helped
i would suggest tring diff. settings on the mm and see if it helps, its a pain , but with your gearing it shouldnt be all that bad, try diff. timing and start powers