Now I say that because I havent seen it myself, but a friend who owns a bike shops told me about it so I tend to believe its true.... He knows a guy who stuck a honda 50cc 4speed on a Tomos with very little engineering..apparently it screams pretty good and he hasnt been caught shifting gears yet. they have been making that same motor for like 40 years and still make it and damn it all to hell don't ya know I threw one out a few years ago...Rog