Thanks tomplum,I used the JD parts site exclusively during the rebuild. It seems that when the bolt that holds the pulley and PTO on is tightened the drive pulley on top gets sandwitched to the bottom of the frame. I took the belt off to make sure. I bought some brass spacers I'm going to put on the top and see what happens.

What's the serial#? There's different schematics for those above/below 070000. Deere schematics are rather "tedious", so I don't want to waste time looking at the wrong one. There ARE multiple fuses to check that could prevent relays from functioning.

Could be one or more interlocks. My first choice would be the ignition switch (key). Sounds like intermittent contact. Second choice would be the solenoid. Do you know how to jump the solenoid? This would help you focus on whether either part is the culprit. To jump the solenoid, you need to put +12v to the third wire (the smaller connection). Solenoid should click and start cranking motor.

Kawasaki FB460V engine. A free PDF manual for the engine can be obtained at "my mower parts dot com" (but translate that into a genuine URL to get there). OP still has not confirmed if this tractor has a electric PTO clutch but some internet searching indicates it likely does. While it is not typical for a BELT DRIVEN blade drive system to result in shearing or bending of a flywheel key it is certainly possible that in this particular case (lift arm disengaged and dropped deck assy) the stopping of the blade belt was abrupt enough to shear or bend the flywheel key. Usually a belt driven blade system (and thus the engine crankshaft) will not stop turning quickly enough when the blades encounter a significant foreign object to cause shearing of the flywheel key. The saving grace in belt drive systems is that the belt usually slips enough that the inertia of the engine is absorbed relatively slowly......and the key survives intact. However.....in the case of the deck being dropped downward suddenly by the lift link letting go......the belt would have been given an added bit of tension (by dropping too far down) and that just might have been enough to shear the flywheel key.