While installing the belt, the V-shaped side needs to go on the inside. The Mower Deck Drive Belt broke. John Deere advertising claimed it as a horsepower tractor, although later verions used the same 18 HP engine as the John Deere Garden Tractor Parts.
Deck X, in. I bought it used and dont have a manual, the belt that engages the blades broke and just need to know the correct routing for the new one. “John Deere X390 Drive Belt Diagram”