Question On Clutch???

I was riding my 400ex and i felt it "losing" power but i am pretty sure the clutch was slipping then my clutch handle let go like the clutch cable had snapped but it didnt does this mean the clutch is out. The clutch swingarm still moves as does the cable, but no more worky on the clutch. If so how much does the stock clutch run? thanks alot
pilsbury