Husqvarna EZ 5224 Not starting, solenoid vs starter, or electrical loss.

I have a Husqvarna EZ 5224. The hydro belt burned up. So I disconnect the battery and commence replacing the belt and seized idler pulley. When everything is fully reassembled, the mower doesn't start. Now replacing the belt happened slowly over 2 months. But it started and ran before I replaced the belt.
 
When I start it, the starter engages the flywheel, and clicks repeatedly. It will not spin the flywheel or turn the engine over.
 
So I charge the battery. It reads 14+ volts. Same.
 
I test the voltage at the solenoid. Also 14+ volts. I bypass the solenoid. Same clicking with the starter.
 
I measure the voltage at the starter. 11.6v. So a good bit of loss. Is this enough to not engage the starter? Or does the clicking signify the starter's clutch slipping? Should I just replace the starter and solenoid? Should I replace the battery wiring because of the voltage loss?
 
Thanks,

Ok so I pulled the spark plugs. No luck. The engine has not seized. I can spin the flywheel and engine over freely by hand. 
 
I've never heard this clicking before when dealing with battery issues. The clicking is the starter trying to spin the flywheel. But nothing turns. And when I bypass the solenoid, I get the same thing.
 
Maybe I can post a video of it tomorrow.
 
Starter gone bad?

No the starter will not turn the engine through with the plugs out. I can spin the engine by hand with the plugs out.
 
How would I check the valve clearances? And what failing would cause this to change?
 
I'm going to replace the starter. Thanks for your help.
 
Here's a video: 
www.vimeo.com/325100877  

Yeah looking at the video, I would rebuild or replace starter.