Ariens Zoom 42 won't go, mystery part?

[Wayne-o]

I have 10 year old Ariens Zoom 42
Kohler 22 hp, 72 cc engine
The other day I was straightening up the yard and found a mystery part but did not know what it went to.

Yesterday I was cutting the lawn and suddenly the zero-turn stopped moving forward or reverse.
I checked and the drive belt was off the pulleys. I put it back on but still no response from drive levers either forward or reverse.
The drive shaft spins fine after starting but I notice that the drive belt is very loose.
I saw a Youtube video where someone reported the same issue and held up a part that looked just like mine.
It is black rubbery/plastic but I cannot locate it on any of the exploded parts diagrams.
Where does this part go on my mower ? (and what does it do?)
Is this why my mower will not move ?
Thanks

 

[Sangalli]

It appears it may be part of the electric clutch assembly on the engine shaft. Does the clutch engage that you can tell?

 

[Rivets]

I don’t think that it is a part for your unit, just my opinion. Check to see if you might be missing the idler arm spring, which keeps constant tension on the belt.