Motor Question
 

What is the reason for the Capacitors on the motors?

think of capacitors as little batteries. they store power , and i think (not sure) but i think that they give the motor a more even amount of power...maybe

They filter noise that would otherwise be thrown back into the electrical system of the car, causing interference with the radio.

Yup. Capacitors are essentially high-pass filters that allow high-frequency noise to short through them (to ground in this case) and out of the car's electrical system. Remove them and you'll probably get some nasty glitching or other bad reactions.

Capacitors do not add power, but they do store charge and can release it when the main power supply voltage drops (the batteries). In this manner they help smooth the voltage signal.

FETS, BJTs, and other types of transistors can be used as amplifiers to effectively "boost" the power fed to the motor.

or as i've always been taught, they smooth out the voltage current. kind of like a boost bottle on a nitro engine, that is if u know what that is. here is a picture of a boost bottle. i have one on my nitro rustler. i didn't hook it up cause i didn't want to damage the carb, but when sitting on the back and with the logos scraped out and repainted blue, it looks like a small nitrous tank. its the things on the left side.

Alright, Now I understand. Now I need to get some of thoes capacitors when I go get a pinion puller before I install my SpinBrush Motor.

Or you could just remove the set, still attached to the brushes, from another motor...

I was thinking of getting a set of Stage 1 motors. (The wires on the Stage 1 that came with my car keep braking off...) Then I could use the ones off of the Stock motor that came with the car.