And do it have to be a Yam? Various Hondas are about, and best HD mickey take of all, they do an industrial pushrod v twin, just like B&S and Kohler.
Main reason for going down the Yamaha route is tht I have 4 donors in my garage ! One will be the basis for my 60's Brit Bike styled Cafe Racer [ along Vincent lines ] and one other for Cafe Creme.
That still leaves 2 - one I will probably sell to raise funds for the other projects - the other. I'm still toying with the idea of a Boardtracker chair - along the lines of the "Union" Bike. I have a pal in Germany who makes replicas of the Stoye chair - the Mk1 at the moment, but I've talked him into making a rep of the Mk2 [ with the ribbed nose ].
As to the smaller bike - I really admire the looks and enginuity of the smaller bicycle Boardtrackers, but as I said, it would be cruelty in the extreme to ask one to pull me along. That leaves a physically small V twin with the scope for plenty of reasonably priced donors and spares. Comes back to the 250 Virago. Unfortunately I don't know enough about modern [ to me ] bikes, so I'm not familiar with what other small capacity air cooled V Twins might be out there.
Maybe a thread with suitable donors and inspirational bikes ?
Apologies DD ......... will try to take this "shootin' the breeze" elsewhere'