Re: American made Kit w/Engine on the market?
I doubt you can get a new, US made motor kit.
The Cushman drivetrain was US made; Briggs + Comet CVT.
However, the big Briggs has too many cc's to be street legal on a motorbike in most states.
A US made chainsaw engine might do it.
“You're only young once, but you can be immature as long as you like" -Unknown