that is funny you mentioned that. YES it did run backwards once. I was on a hill and rolled back and POOOFFF the rear tire started turning backwards. At the time I had no idea what was going on so I just turned it off and restarted it and it was fine. are you talking about the reed valves? or answering the last trivia question? did your dt 360 engine ever run backwards? still looking for answer on yellow bike question.