I agree with statements that OEM belts are good, but I've had better luck with Gates Extreme belts. I liked them so much I got an account with a supplier and get them at cost. One thing to think about is... who makes the belt FOR Yamaha??? They certainly don't make them themselves. According to my Gates contacts, they make the OEM Yamaha belts, but reserve proprietory technology for their own belts, making them marginally "better". BTW, I worked in an industry where many belts similar to snowmo belts were used on machinery. They were a different length, but similar. Dayco sucked and had little life expectancy, and frankly were the laughing stock of the industry. Gates had a much better reputation. Call an industrial supply house like Applied (nationwide) and ask for a candid opinion. I think Dayco sells a lot of snowmo belts because of their flashy packaging, but the product is not as good as Gates.
I the meantime, if you want to try one, I can hook you up with an Yamaha Extreme belt for about $48 plus shipping ($3.85 priority mail). They are $64.99 through Dennis Kirk