My problem is the dc will spin fine at 40 psi but anything greater than that it won't. I am saying this because as soon as I shut off the flow and unscrew the top-it is not spinning (if I take it off fast enough I catch it stopping-total of 10 seconds}.

There is plenty of flow, and no clogged jets.

Oil is 160 degrees.

Rotor appears to be fine along with the o-rings (though I have accidentily had the psi spike to 120 psi for a few seconds). I usually run the psi at 80.

Took the center shaft out and made sure there was no obstruction. Ran some oil through the without the rotor assembly and oil came through fine.

Any ideas on what is going wrong here?

Does your oil flow freely out the bottom or do you have it piped somewhere? If there is any restriction in the outflow the oil will back up into the bottom of the CF and stop the spinning. I had a 1" nipple on mine for splash control until it started doing the same thing, when I removed it the problem went away. Or, your PSI spike distorted the bowl and now it can't build enough pressure to spin properly. Do you have a second bowl you could try? HTH

It is free flowing out the bottom.

No second rotor to try.

I tried just putting the outside "bell" on just a couple of turns to where it splashes out some. And it is working fine like that.

This really has me puzzled.

Maybe your center bronze bushing in the rotor has unscrewed partly from the cast base, making it stick up too high? Try and tighten it, a nail through the 2 holes works good.

I am not sure but the bushings look like they are where they should be. And I could not find where I would be able to tighten them. This centrifuge is only about a month old.

And by the way Sun, thanks for your enormous contribution to all with centrifuges and svo knowledge. It has helped me greatly.

You're welcome. The center shaft that contains the bushings screws into the cast base. There is a hole halfway up going across the shaft, and you can turn it there with a nail.