I found the old bushing to the 49cc 4 stroke I had. I remember one time the bike got stuck in gear because this piece must have galled to the clutch bell. Has some dark streaks that won't come out with a paper towel so probably when it got hot and dried up. It had a toothed belt. I lost this piece so I couldn't sand it and re grease it. It is a crappy design just throwing in a plain brass tube for spinning and friction.