not if geared right , i ran a mmm and a novak 4.5 , its geared 12,68 ... or what ever the stock spur gear is , this motor ran @ 135* at the endbell , which is the warmest point i could find, the heatsink is about 10* less from what i have found
I've run both the the HV7.5 and the HV4.5 on my MMM. The breaks on the MMM are definately smoother. There is some cogging from a standstill, but the throttle is smoother overall. Temps seem to be a little bit better with the MMM, but it is hard to say for sure.
Check out my custom converted 8ight:
Sub 7lb, lowest CG of any 1/8 buggy