In the scene where John is in the Garage with his 1990 Honda XR100, watch him Rev the bike...You will notice that the bike sounds and throttle twist do not match up. This is because a Honda XR100 in REAL LIFE is a 4stroke, meaning its slow and sounds VERY ROUGH (ex- brrrr brrrr....) In the movie, they changed the sounds to a 2-stroke (such as a Honda CR) which sounds very loud (Waaaa..Waaaa..)This clearly came to me since I own a 2-stroke, and ridden THE SAME model XR before used in the movie. And people have said before when he changes gears when exiting the mall, it doesn't match with the sound, this is why.