Blades do not disengage when I move the attachment clutch lever (there is a slack in the cable). I need to move the cutting deck up and down to get the blades to disengage. There is a lever (arm) under the Pulley, Mandrel that I can push by hand that causes the pulley to side forward and disengage the blades. The sliding of the pulley forward takes the slack out of the cable that attaches to the attachment clutch lever. Obviosly something is worn or missing if I need to do this manually. The lever that I am moving by hand moves easily and disengages the blade as the pulley moves forward.

Hi,
You say it moves easily, so the most common problem does not seem to be yours. That would be corrosion on the spacers where the idler arm pivots. That would seem to only leave the cable (#17506) as the culprit.
If you want or need it, your manual is at:
Owner's Manual - CRAFTSMAN Lawn, Tractor 917273399 - ManageMyLife.com
Peace,
Clarke

I have a Model 917.273399 Craftsman tractor. The blades do not disengage when I move the attachment clutch lever (there is a slack in the cable) to the disengage position. Upon further research of this problem, I am able to get the blades to disengage my moving the (Arm Assembly, Pad, Brake) lever by hand away from the Mandrel pulley. This causes the idler pulley to slide forward, the blades disengage and there is no slack in the cable. How can I fix this to work as it is supposed to?

I have a Model 917.273399 Craftsman tractor. The blades do not disengage when I move the attachment clutch lever (there is a slack in the cable) to the disengage position. Upon further research of this problem, I am able to get the blades to disengage my moving the (Arm Assembly, Pad, Brake) lever by hand away from the Mandrel pulley. This causes the idler pulley to slide forward, the blades disengage and there is no slack in the cable. How can I fix this to work as it is supposed to?

My tractor shuts down after running 35 minutes. Once the engines cools down it starts right up. Could this be the coil? Where is it located on the engine?