Here's an answer that contains a link to the PDF of the Operators Manuel: http://www.ifixit.com/Answers/View/16172/Need+to+replace+mower+blade+belt
If this is not your machine, go to this link and enter your machine number for the PDF download on all the parts, most belt routings are around page 10: http://search.cartserver.com/search/search.cgi?cartid=a-8671&category=MurrayPDF&maxhits=5&keywords=40504X92&go=GO%21