This is the startup procedure of the 1928 Morgan Aero with the water cooled 1100cc LTOW JAP V-Twin engine.
what a sound track from that JAP!
Two speed transmission.
The V-Twin drives a shaft to a bevel box located under the seat. Either side of of the bevel box are two sets of chain and sprockets with a crude but effective dog mesh to engage drive through one or other sets.
she cruises happily at 50mph but will do more if you're brave 😀