Stealth Pilot wrote:
I looked into this a while ago.
there are no engines available as spares so the only way of obtaining
one is to buy a bike and throw away the frame.
the bikes cost $33,000 australian dollars
a jabiru engine is less than half that and it was designed as an
aircraft engine.
does that make any sense to you?

Stealth Pilot

German ebay lists quite a few for reasonable price:
http://cgi.ebay.de/Motor-BMW-R-1100-...item1e57ed6b9c
http://cgi.ebay.de/Motor-BMW-R-1100-...item3ca8d64508
http://cgi.ebay.de/BMW-Motor-R850-R1...item2ea8f7c2ff
http://cgi.ebay.de/BMW-R-1100-GS-R-M...item53dae8c437
http://cgi.ebay.de/BMW-R-1100-GS-R-M...item53dae8c46d
....