Sorry to be funny but, at this time of the year confusion is par for the course. Today a customer told me he needed his snowblower fixed right away so he could put it in storage by next weekend. Even paid the extra $50 to jump to the front of the line. I'm confused.
It's a MTD part number sure they just make Yardman, they make several. Here's a link of what you need item #31 is PTO belt, link isn't posting right but there it is or just go to parts tree and search that model number