Got my 9920/XL1600...

Now that I've had a chance to give this new setup some good runs I've noticed a interesting heat issue. After a hard run, the motor can is just warm to the touch, never really hot, but if you touch the end of the armature where it sticks out of the bearing in the back, it's so hot you can't touch it for > 2 seconds.

Should this concern me? It's geared 72/20 right now.