There are no tags on the mower to tell me what model I have. After 3 days of looking online, I think I found a number for my unit. My mower belt broke and I am trying to replace the mower belt. Your website manual shows a picture with 5 pulleys. My machine only has 4 pulleys. My machine has a Briggs and Straton motor and my machine is a 15hp 42" mower. Can you help me figure out what size of belt I need, and the diagram of how to run the belt? Thanks Dan