I recently received a Murray Ultra 12hp 30 in riding lawn mower . The transmission belt was broken, the only piece of the belt I could find , did not have any measurements , size , or mfg#. Does anyone know the size of the belt I should buy ?

If you have a good lawnmower repair shop in your area they should be able to tell you exactly what you need and will probably have it in stock.

I have tried to find repair parts for my lawnmower and snow blower online or even get suggestions on this site with little success. Once I found this repair shop that is dedicated to that type of equipment I was all set. These types of places are highly knowledgeable (it's what they do all day).