Well, I was reading up on my YT60 history and mods via the almighty google, and found that people swapped the 2 speed bottom end of the MJ50 moped onto the QT50 Moped, and slapped a YT60 top end on that.... My thought is we could slap a YT60 top end on an MJ50 2 speed bottom end, and slap that in our Tri Zingers??? a 2 speed Zinger! I guess the only question would be the mounting in the frame and if it matches. If not, something could be rigged up with a few hours and a welder.