Since your in Europe consider Some of the 125 to 250 cc maxi scooters they make over there . Most of them will do between 100 to 130 K flat out which could get you around on the older byways . There s loads of people whom have taken the old honda CT110 outfitted it and going form London to India. It's all about how much time to you want to take. How fast do you want to go? Most 125 to 250 cc bikes and scooters get 70 to 90 MPG. The old honda cb125 got 100 mpg . here a good place to start to look at what is what over there . The honda c90 isnot fast but can and has been out fit to tour with a second gas tank, rear racks etc . http://www.motorcyclenews.com/ Suzuki GN125
Yamaha XMAX 250
Life's journey is not to arrive at the grave safely in a well preserved body,but rather to skid in sideways totally worn out shouting WHAT A RUSH, WHAT A RIDE.
Got to go places to be, people to kill and far to many woman.