Blades will not disengage

My craftsman Lt1000 mower blades keep turning at about half speed when mower lever is not engaged. This just started after mowing for first time this spring. last week. Ive tried cleaning all rust off all parts, greased in between washers. No broken belts, no springs are missing as far as i can see. It mows good when lever is engaged. They just dont stop when disengaged. Can someone pls email me at eucredawwg-yahoo.com if you could help get this resolved.thanks