brushless losi 8b

i was having a bit of a think and surely the motor should be run cooler in the buggy than my old revo? i used to have the revo geared on 40/16 and the motor was quite hot to the touch but no where near what it is in the buggy
the buggy geared with the stock spur and 16t pinion means the motor gets very hot. i was wondering if there was any binding but all the wheels seem to run smoothly and it free wheels for a long time on road?

what would be the signs for binding ?