I believe the no load current for the 9L is 3.3 amps. That's 55 watts of power that's being turned into heat.

yeah.. plus it is revving at a higher RPM than it normally would, which could cause the magnet to some loose from the shaft.

Yes, 1 minute, full throttle, 14 cells. All three motors escaped unscathed (as far as I know). I've got to play with gearing more, it just seemed so counter-logic that I could gear it taller and tax the motor less! Time will tell.

i strongly advise not to let those motors run unloaded at all.

Thanks. I don't normally do that kind of thing. I think i was trying to prove that all the heat was coming from the high speed and not load. Getting them up that high with no load tells me that gearing is key.