Moved one spacer to the inside of the impeller.
Found the "Torsional Damper " (#24 on Drawing) almost gone :

The synthetic washer was squished & almost off the washer stack.
(Installed new one after 2 spacer on first)

With one spacer seemed to look & spin good.
( I left the key, #18, out & tightened so I could spin the impeller by hand )
Put the key in & took to a local lake to test run on the trailer.
Is ran for a few seconds at idle, the died, & wouldn't crank.
Removed impeller, found a few aluminum chips & one stuck to the impeller.
Cleaned & sanded the cone, assembled, test run again, Same thing. run a bit & die at idle.
3rd time I started at a higher RPM, then back to idle after a minute, it died.
(Yes, mosquitoes were out in force )

After 4th time, I marked the cone so it go on the same bolt (stud) & carefully
tightened like you to a tire wheel (X) pattern.
I'd read that there is a little play in the cone bolts , ( proved that to be true )
It made a difference. It ran at idle.
It ran OK but I pulled it again to be sure, found a few small aluminum chips,
I sanded the cone where they'd come off of, installed & it ran at idle.
Called it good to go .

Cleaned, sanded, test run 5 times before it quit making aluminum chips.
( No noticeable wobble in the drive shaft ) (4 blade stainless impeller)

Am guessing that running in the silty Knik & Su will polish it up even more, after a few minutes at 5000 RPM

Any other tricks out there ? ( am relatively new to jet drives, but learning )