Fantasy - medieval European clock maker's son kidnapped by pirates and travels to China. Read early 1990s.

[James]

Genre: fantasy

Plot details: medieval European (German or Swiss?) clock maker's son must flee his home to avoid a "shotgun marriage" with the local strumpet. His family is wealthy enough to send him far away - but his ship is attacked by pirates. He escapes but ends up on a wild adventure that takes him all the way to China. Along the way he rescues a princess from slavery. Once in China he becomes a guest at the Imperial Palace and learns the customs. He also becomes involved in bringing the Chinese invention of the magnetic compass to the West. He returns home finally, now married to the former slave/princess, and discovers that the previous marital difficulty sorted itself out while he was gone.

What year I read the book: early 1990s?