Oracle Delphi Mk V suspension height

I just acquired a Delphi Mk V to replace my old MK I/II.
When I set the suspension height to 20 mm the belt falls below the inner rim. I have finally set it to 17 mm & can see about 1 mm of the inner rim below the belt when playing a record. The distance from the top of the plinth to the top of the drive pulley is 70 mm for a spec of 71 mm. Can anyone comment on their suspension height (bottom of tower skirt to plinth)?
Mine are right at 20mm. My belt rides up about 1 to 1.5mm on
the inner hub.

Are you sure you have the right (color) springs where they belong
and are using the correct springs for your tonearm? Also check
to see if the springs are seated right and nothing is getting in the
way, like the felt dampers.

Make sure that nothing has gotten into the bearing/spindle well
that would be keeping the platter from fulling seating down.
The springs are correct (yellow, red, green) & seated correctly, 2-3 turns show below the holder. The bounce is good. I did not disassemble the bearing to check the thrust plate, but the spin is free. The distance between the bottom of the platter and the top of the sub-chassis is ~2.5 mm.
For me to get 20mm the platter would be touching the sub-chassis. I also have a concern that there is ~1 mm vertical play of the motor shaft. This might explain why the deck to top of pulley is 70 instead of 71 mm, but I cant explain the 3 mm anomaly. BTW does anyone happen to know if the Torlom thrust bearing for the Mk VI can fit the Mk V bearing?
Check the sub chassis to make sure it is seated on the posts (towers) correctly. Maybe one might be off just a bit and not fully engaged into the post/tower.
Oldears, when you get this sorted out, can you tell us how the Oracle V compares to the Oracle 2? I'm less interested in the sound(other than in the bass), and more interested in the effect it has on listening enjoyment-not so much in discovering new information from well-known lps.
Wrote Oracle Tues & Wed, no response yet. Went to Lowes & got a faucet handle removal tool. Raised the pulley by 2 mm to a height of 72 mm above plinth (spec 71). Raised the skirt height to 19mm (spec 20). Good enough for me. But the Oracle specs will not allow the belt to stay on for this model.
Note I have owned & maintained an Oracle for 33 years.
For the sound question: The old Oracle is a Mk I with the Pabst Hall effect DC motor, the Mk II suspension, a Perfectionist Engineering polymer bearing, a separate linear 27 V DC power supply, an acrylic platter mat from Holland, and is in good working order. The replacement is a Mk V SE (with granite base and Turbo PS). I took the tonearm & disc from the old table to the new, & made minor adjustments in VTA and azimuth.
The individual sound differences are not as large as you might think, but they do add up. The biggest difference is in "jump" (macro-dynamics?). The bass goes only a little lower, but is cleaner. The imaging width & depth is a little better, the noise level a little better (micro-dynamics?). The sound is a little more precise throughout. The sense of realism is much improved. I couldn't go back.
Thanks. I'm pretty sure I never even came close to setting up my Oracle Mk 2 correctly.
Rec'd a response yesterday from Oracle. My setup is OK. The 1mm free play of the motor shaft is normal. The Torlan thrust plate for MK VI can be used in the Mk V bearing.
Perfectionist Bearing is the poo brah! Brooks Berdan installed one on my Mark II along with the clamp and the separation of instruments in recordings was evident. I use the clamp on my Mark VI now.
Those not familiar with the Perfectionist Engineering polymer bearing are probably puzzled I did not find huge differences in my old Delphi I/II and the Delphi V. Unfortunately this guy suddenly disappeared and the supply of polymer parts was very limited. It took a while, but I have now installed the bottom part of the Mk VI bearing in my Mk V. This means the contact of the spindle is now fully dampened by polymer. It gives an even lower noise floor (very quiet), fuller bass and more nuance in the sound.
glad your enjoying the Oracle. I loved and miss it.