I can't remember when the motors bumped up to 865 but here's one for a 790cc model pretty inexpensive:
http://cgi.ebay.com/ebaymotors/01-Triump...s#ht_4348wt_939

A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort. Herm Albright (1876 - 1944)