In my experience owning the YTS3000 I spent more time fixing or replacing sht than mowing. 1 BIG money pit. I think I have rebuilt almost the entire thing except the main drive belt because the large main metal pulley is frozen under the motor and won't come off. I took the long bolt out and beat the pulley with a rubber mallet. Stuck. I heated it up and pried ,beat and pulled on it. Nothing. I sprayed PB Blaster everywhere 3 days in a row and pulled, pried and beat. Still stuck on. You would think they could have put some anti-seize lube on there but it would have cost them 50 cents. Maybe a harmonic balancer puller will break it loose. Luckily I have a new Cub Cadet Ultima 42" deck and 22hp V- Twin zero turn now and the Crapsman to pull loaded wagons.
In your description, you have #197379, the OEM number for my Craftsman is #193197, per my Repair Parts Manual. But searching around the net, says it replaced by #177968. My idler pulley made a loud racket and the inner bearing was destroyed. It slipped right off the bolt. Now to buy replacement parts. Wish I could find them IN stores. I hate online buying. Wish this grandma good luck.