Was the engine turning when you heard the noise? Or was it screeching but, no pumping of the cylinders? This sounds like the starter clutch, not the starter.
Who was it who had this problem in the past few years? I can't find it. Berlin Bob via text?
As Bruce mentioned, there's a one-way sprag clutch in the primary drive area of the engine. Page 70, item #10 in the parts catalog. When they slip, they make an awful screeching and crunching noise. I've never had one fail on a Super X but, had them go bad on numerous other bikes. If there's no obvious damage to the starter motor, that's probably the source.
