Never ran Novak, but if the motor got too hot, you might have at least partially demagnetized the rotor. When this happens, it pulls more current to produce the same output power, which heats it up more, which demags it more, and so on. While this is happening, all that extra power shows up as motor heat, but little if any speed output.
You could either get a new rotor (if in fact it is the problem), or get a MMM/Neu combo. With the MMM/Neu combo, prepare for more broken drivetrain parts and it is a "bit" more powerful.
