Checking Pulley Alignment
The belt needs to be removed to do this.
You will need a straight edge and ruler to measure. First draw a diagram of circles, one representing each pulley. The straight edge will be kept on the face of the crank pulley for all measurements.
Remove the belt and place the straight edge across the crank pulley. Measure from the straight edge to the first peak on the crank pulley. Write the measurement in the circle representing the crank .
Keep the straight edge on the crank pulley and re-position it so you can measure to the first peak of each of the other pulleys with ribs. Write each measurement in its circle on your drawing.
Comparing the measurements will tell you if anything is misaligned and by how much.