Band saw wheel setting

[black]

Need some help with my band saw guys.
Its a vertical band saw that I bought for re-sawing cants and have never gotten it right.
The machine is a Member sr900 with a auto feeder. Every time I change the blade the wheels need to be reset. The band just runs off the wheels, but the machine has got low hours so it cant be the crowning.
The bearings are good as well so what you think?