I just picked up a YT16H (I know, it's not a big garden tractor), and the deck drive belt is bad. The tractor number is 9607432 and the deck is number 09GN3683. It seems like Gilson changed little things every year in the 80s so nothing is quite the same. I'm currently sifting through the service manuals that KennyP (think that's his handle) posted. Also, should the PTO spin even if there's no belt on it? If the tractor is on and running will it engage with no tension on it? I get the red light so it looks like there's power going to it but the pulley doesn't engage.
This is my first tractor so I guess my cherry has been popped with this one. All in all it's in good shape. It runs pretty well. The deck belts for the blade spindles are new, just that drive belt was bad. Any help would be appreciated.