Thanks all for your replies, I posted the very same question on a HD Forum and nobody so much as asked "you crazy?"
Anyway, once in the lower 48 I have 90 days to cruise and my intent is to visit as much as possible and then crate the bike in Baltimore, Boston or NYC and sail home.
Although I have relatives in Colombia #wife's family# I do NOT intend to ride South of El Paso or wherever.
If I really wanted to do S.America, I'd sail from L.A. #or Portland, for that matter# and go straight to Lima, Perù.
Sure, that means missing out on Central America, but the odds are happier on getting mugged vs. getting free gas.
#and once I'd visited Peru Chile and Argentina... Brazil... set sail for South Africa... safe up until Ethiopia but riding across the Sudan ? Egypt ?
#
And anyway... I'd need a bigger than 2 1/2 gal tank !