The sound used to do impressions of the sound motocross bikes make, a 4 stroke will be uttered in a lower tone. A two stroke will be much louder and high pitched.
Must be repeated a few times with added intensity, the term "ruUuuUTTt" can also be added when the speaker feels the need.
1. Two stroke - BrAaAaAp brAaAAAaAappp braaaap BRAAAAaaAAAAp!!!!
2. Four stroke - BrAaAaAp braAaaAaapp brapAPaPAPp RuuuTTtt braaaaaAAap!!!