i have a multiple entry business visa 90 day duration of each stay that reads: Enter before 04/09/14

Hi Multiple Entry one 90 day duration of each stay that read Enter Before 04SEP2014, now its September 26, 90 day max duration so im OK within china, question is can I go travel outside of China and come back since its a multiple entry type, or since it said enter before 04SEP2014, that was the last entry permitted for me no sep04 and now it means I cannot get out... please advise
thank you