6 months....
....India and Nepal...with my g/f (now my wife).
Bought a 1955 Enfield motorcycle with a side car and drove it all over India (couldn't handle the aspiration at higher altitudes so I had park it in Shimla or Manali - can't remember which it was 20 years ago), but other than that took it pretty much everywhere.
Had a great time one of the best trips of my life.