Ok there are many different kinds of RC brands and cars. I have a Traxxas Stampede and I will recommend Traxxas to anyone. If you need parts try your local hobby shop. MY FAVORITE ONE IS
www.larrys-rc.com or Larry's RC.
Step 2: Find The Problem
Ya ya ya I know your going to tell me that your problem is your motor is over heating. We need to know what is causing it!!! It could be a simple spur gear that is problem. (Over-gearing/under-gearing) or it can also be that you are running your motor to hard. Or you could have the wrong motor in your car. Anyway I have solutions for all of these!!!
Step 3: Over/under Gearing
To find out if you are over or under gearing your car you can take off the gear cover (on Traxxas's) or what ever protects your gears. Look at your pinion gear and look at the number on it. Say you have a 12t motor and your pinion says 23 you are over gearing. This will over heat your motor alot. For a 12t a good pinion is about 18 or 19. If you have a different kind of motor tell me in the comments and I will try to tell what a good one would be! This helped my car ALOT my motor doesn't get hot anymore.
Step 4: Running Your Car To Hard
Depending on your car, you can work your car to hard and even know it. If you run your car in the grass it can dramatically increase your motor temperature. Another way is running your car at its highest speed the stopping and then turning and then full speed again. This can over heat your esc to. Last but not least don't hold the throttle well in the air like on a jump don't keep excelerating
Step 5: Finding The Right Motor
Finding your RC cars right motor is important! Would you put a GMC v8 in a Honda? So don't put a brushless fireball 21d motor in a TRAXXAS 12t car. Refer to your RC car manual.