Cleaning Motors?
 

I am swapping my 55t motor with my 21t motor but it was on my truck and its covered in dust do they need cleaned? is there a special way if they do?

Have a look in here man: http://www.rccrawler.com/forum/electronics/223989-cutting-motor-commutator-motor-tweaks.html

Got everything you will ever need to know about motors.

You can do it by pulling down the motor. Using a little soapy water & a toothbrush. Lube bearings put it back together...Done.