Josh Franta explains that if your motorcycle is not starting it is likely a bad spark plug. He leads you through the process of replacing the spark plug. Oil residue builds up on the spark plug and blocks the electrodes and prevents the motorcycle from starting.
Step One: remove the spark plug's protective covering by pulling it off.
Step Two: loosen the spark plug and remove it.
Step Three: hand thread the new spark plug into the engine and tighten.
Step Four: cover spark plug with protective covering.
That's how easy it is to change a spark plug.