So I have a 2003 Cub Cadet 1525, which has been ultimately the most trouble free device I've owned.  Recently, it just shut off while cutting grass with some leaves on it.  I took the deck off and the blades and pulleys spin (shouldn't be able to stall 15hp).  I took the clutch off and it seems to be loose so I tightened the three nuts until there was a little drag.  Before I put the belt back on...is there something I am missing?  The clutch is tight now and engages the pulley and the deck pulleys spin free.  It would literally just start smoking the belt before and I just couldn't figure this out.