Repairs Craftsman riding mower Model #917.275820

I have a mower that will only start by slightly engaging the PTO handle. It also dies when you move it to reverse. Also the blades won't turn when you engage the PTO.
Anyone have where I should start looking?

That is the model with the candy cane pto lever slot.
Is there resistance on the lever or is it slack ?
Behind the dash there is a switch which most likely has come loose.
The pivot bolt that the pto lever runs on is most likely flogged out, or loose.
The cables do break.
On the deck the spring cuts a groove in the tensioning arm so it can not move far enough to tension the cutting belt.