Sounds like the ring hasn't seated yet. Only a couple tanks through it?

Forget setting the idle... it won't set correctly if the ring's not seated.

Do a bench run with a 13X8 MA black nylon prop. Run at the edge of too rich. It needs to get too warm to be comfortable to touch, about 1/4 to 1/2 turn open from peak rpm. Be prepared to run a FULL 12 oz tank at constant full throttle. (maybe 2 tanks...) When the ring seats, the rpm and tone of the engine will change suddenly. IMMEDIATELY retune the way you'd normally adjust the ABC, non-ringed engine's you are used to., and run at appx 75% throttle (varying from 50% to full is OK)

The main needle setting can change by over 1 turn when the ring seats. sometimes... it takes several tanks of fuel to seat the ring.

That should cure it.

If you store the engine... make certain you clean it of all fuel residue by removing the glow plug and use a starter to turn it over, drawing from a small fuel tank with 1/2 oz of after run oil in it. Draw ALL the oil through the engine that way, and there should be no problem with the ring sticking (which can make it nearly impossible to start the engine after its been stored 3 months or more)