Give this a try it may help
Tuning a Band Saw
Unplug bandsaw when installing and centering blade.
Adjust tilt of top wheel so blade is running dead center on the wheels, spin the top wheel by hand to check.
The tension should be just enough to prevent slipping on the wheels but not enough to stretch the blade, the wider the blade the more tension required.
If there is too little tension the blade will not cut straight, increase a bit at a time until you feel you can control the cut.
Some inexpensive or damaged blades will wander no matter what you do.
Set guide blocks to miss the teeth but support the rest of the blade.
Wrap a single layer of 24# paper around the blade to set the side clearance.
The back up roller should be set so it does not turn when idling but will support the blade when cutting.
Condition the back of the blade, with the blade running hold a sharpening stone against the back corners of the blade to round them off, this will allow you to cut sharper corners with less binding.
Check if table is set square to blade, otherwise your cut will not be 90 degrees.
Set fence to blade, most band saws do not cut parallel to edge of table so the fence has to be adjusted accordingly.
Mark a line about 3" from and parallel to the straight edge of a 12" square scrap of plywood, make a cut into plywood following the line for about six inches.
Stop the saw, keeping the plywood in the position it was in while making the cut.
Align the fence to the straight edge of the plywood.
There are many variables when setting a band saw, each blade will have its own characteristics, often you may find that you have to go back and tweak some of the previous settings again as you go through the procedure.
It can be a time consuming exercise, but well worth it in the long run.