Rummy's Savage E-5SC

I sure hope it's not the motor. Those 1717 motors aren't exactly everywhere. 75,000rpm????? Highly unlikely but who knows. Did you take the motor out and try to turn it by hand? Should also take the front of the motor off and have a look at the state of the rotor.

IMO the slipper on the Savage is way too ineffective even on a normal Flux. Same thing as you have found out. Either it screams in agony slipping or you have to lock it to the point where you might as well not have one. Have a look at the slipper eliminator from Alza racing.

Edit; Just had a closer look at the graph. It states (to me at least) that it is the readout for a 2 pole motor. The 1717 is a 4 pole (ahhhh duhh). Anyway that 75,000rpm can be halved. I think you only hit 35-37K. I hope I am correct here.