This temp seems fine. If I am not mistaken "hot" would be over 150 degrees. So if you are doing 140 you are doing perfect. I run about 143 after about 15 minutes of running my 9xl on 5s2p A123. Oh and that is with fans on the motor. So I think you are doing better than I am. Here is some good information for motor like the feiagos and the mm on how hot is hot:
http://www.rc-monster.com/forum/showthread.php?t=2200