Yardworks 760 15.5hp 42" Deck Belt Issues
I initially thought the reason the belt was coming off was due to the spindle bearing but after i took the deck off i see it wasn't that at all.
I see a place on the deck where the idle arm had a tension spring attached but is no longer present. I purchased a new belt as it looked like it seen better days and have even purchased bearings which i will possibly replace at a later date.
There are a lot of things that will seem like the culprit until you take the deck off and see the whole picture you might not find it.
Here is an image of the deck: