Unusual motored bicycles

[wheelbender6]

The Verdel has a lot of valves to adjust, but at least they are easy to reach.

 

[Fabian]

From looking at the Verdel radial, i wouldn't mind betting it has a 3 hour pre-start valve and tappet adjustment procedure and that's before recalibrating the ignition timing sequence.
It wouldn't be much different to owning a Ferrari; requiring a 3 man team following in a second car to sort out the technical gremlins every time the car is restarted.