Just found some old photos- this was taken in fall of 77 when I was 13. My 2nd motorcycle, a 1976 YZ100. Punched out and jetted, don't remember any of the specs on it though. You can see the down pipe on it- super loud and ran great but problems were greater than benefit. Since it bolted to the frame on the bottom and there was sooo much vibration I was constantly replacing that lower mounting bolt. You can also see how much ground clearance I lost with it. Guess I thought I was pretty bad back then with the suit, florsheim's and a YZ. Good times, good times!