AT 22K RPM the starter motor should still be engaged and stay engaged up to 30K, but 400 degrees is very hot for that RPM...it shouldn't reach 400 until close to 40K

I'm thinking that the starter motor may be holding the turbine back - could be either the battery, motor, or bendix.

If it were mine (I'm saying that because I don't know if this is a recommended procedure)..I would try a dry start ...gas, but no fuel, to see if the starter motor will drive the turbine up to 30K, then cut out..

Use either a nicad or 2 cell lipo..... even a cheap 6 cell RC car pack is good for at least 2 flights.... Lipo's are even better!