The "added" piece is a heat shield and it comes on the new "hush" exhausts. The other neat thing added is the slant head on the 69cc (advertised as 80cc) engines. Some say this adds to the compression since the spark plug is angled at 45 deg. This is my first bike motor, so i do not know if there is a difference. There are a few local motorbicyclists here and we will be are getting together. Maybe they can offer some insight as to any differences.