motor hot to the touch?

i know that the 9L motor shouldnt get over temps of 170 otherwise you run the risk of weakening the magnet, but i was wondering, how can i tell when its close to that or exceeding just by touching it? i was driving my stock emaxx with the 9918 + 9L, and after a few minutes of just goofing around in first gear, and doing a couple speed runs in second, with the gearing at 16/70, the motor got really, really hot. I could just barely hold my finger on it for a second before it felt like it would burn me. I dont have a thermometer at the moment (going to try and borrow my brothers IR one). How hot "to the touch" would the 9L get that is safe for it, and below the 170 F mark? I dont wanna break anything.. .this thing is unbelievably powerful and fast :eek:

oh yeah, im running 14 cell gp3300 with UBEC