Lehner motor temps

[lincpimp]

Just received a used lehner basic 2400xl from skello and have installed it in my pede. Running it with a mm, ccbec, and 4s 4k 20c lipos. After about 20-25mins I stopped runnning as the battery was fading. Took off the body and the mm was cool, the lipo slightly warmer, 100f, but the leher was hot, too hot to hold. Truck is all stock plastic, and is not very heavy. I am running 54/15 gearing, which should be good for around 40mph or so.

Any ideas why the motor was so hot, but the esc was cool and the batt warm? Should I gear up? Did not think that the 2400 on 4s would be running to high of an rpm. Thought the lehner motors were supposed to be really effecient. My previous setup of a mm, feigao 12s, and 3s 4k lipos with the same gearing got at least 40mins runtime. The lehner is only running at about 36k rpm. Any ideas would be appreciated!

Looking at the speedcalc, this setup should be doing almost 50mph, but it is maybe doing 38-40, not as fast as the feigao 12s on 3s lipo.