Every clutch is different. You need to adjust the air gap according to the manufacturer. First with no power to the unit it should spin freely. If not adjust gap till it does. With the power to the unit, it should not spin freely. If it does and you have adjusted air gap without power to it then clutch may be bad. Broken part internally. When you apply power, look at the unit all the way around and see if it came together the same way all the way around. I have found a small stone stuck inside one before that made it not work very well.