Marvel Schebler 905TSX Carb problem

Short version: I recently got a 2020 JD been setting for years, wouldn't run. PLugs, points, cap, rotor - it started but wouldn't accelerate. Pulled fuel screen in side of carb, plugged with rust. Drained gas tank, cleaned out carb with carb cleaner (barnyard repair, you understand) put new screen and gaskets in carb. It started, ran good and got almost home before it died and would not accelerate again.

Drained tank, cleaned out rust good, coated it with Red Kote. Blew out fuel lines, cleaned carb and screen again. Still won't accelerate unless you EAAAASE it up slowly.

Lots of black smoke coming out the stack.

Cleaned and lightly lubed the centrifugal weights in distributor, checked points, plugs, etc. again.

The carb has disconnected fuel cutoff solenoid. I understand they were mostly problematic and most guys took them off (Especially since they're almost $200 to replace).

I tried to buy a rebuilt carb from YT and they are out. But the picture of that carb shows what looks to be an adjustable jet in the place where my solenoid is.

Where do I get such a part (YT says they don't have them)? How do I adjust the carb (where exactly is the main jet)?

Thanks for your help, I'm not a carburetor jockey, obviously.

Red Kote is available from O'Reilly auto parts in my area and also CarQuest carries it. It coats the rusty gas tank with a red plastic that seals the rust in. Good stuff but make sure you get all the loose rust out first. I used five pounds of deck screws, sloshing them around like a landslide kinda to scour the rust off. Also. rinse the tank out (I used gas so no chemical or moisture concerns) and let it dry real good, like a day, before putting the Red Kote in. Blow the fuel lines out too before you go back together. One more thing, when you are sloshing the Red Kote around the tank, get it all on one side, say the bottom, then flip the tank 180 degrees so the coating drips from the "top" onto the opposite surface. It is a more even distribution than you will get with sloshing alone. The stuff has the consistency of heqavy paint. Do the 180-flip on all sides of the tank to ensure complete coverage. Take you time and make sure it dries at least a day or two before reinstalling the tank. Good luck.

It APPEARS Deere part #RE19406, @ about $12.00 is a the manual adjustment screw assembly to replace the $185.00 solenoid.

Also, there may be something wrong in the venturi area, or little passages in the bottom 1/2 of the carb, leading up to the idle circuit up in the top. There are several passages that lead into the area where the throttle plate closes against the bore that may be clogged, adding to the "will not accelerate" problem. (Idle transfer passages.)