Tecumseh TVS90 (Model 43732R) — Won't Start, Gasoline Spraying from Exhaust

Hi all, hoping someone can help diagnose this.
Engine: Tecumseh TVS90, model 43732R
Symptoms:
Engine won't start
When pulling the starter rope, raw gasoline sprays out of the exhaust
Spark plug comes out wet with fuel
What I've already tried:
Cleaned the carburetor
Cleaned the float needle valve
Drained and refilled the crankcase oil (this engine has no dipstick, so I filled to near the top of the fill hole — not sure if that's correct)
None of this has resolved the issue — still getting raw gas out the exhaust when cranking.
My questions:
Since cleaning the needle valve didn't help, could the float level be off, or the needle seat worn out (rather than just dirty)?
Is the choke or primer bulb linkage a likely culprit for this kind of constant flooding?
Should I just replace the whole carburetor with a "632795A" replacement kit, or is it worth trying to source just a float/needle valve kit first?
Also — for the oil fill, since there's no dipstick on this engine, what's the correct fill level? I filled close to the top of the fill hole; I want to make sure I haven't overfilled it.
Any guidance appreciated. Thanks!

I would start by rebuilding the carb with a new needle and seat, part number 631021. I taught my students to use this procedure. I also attached a service manual for future reference. https://mymowerparts.com/pdf/Tecums...P-4-CYCLE-L-HEAD-FLAT-HEAD-ENGINES-692509.pdf

Needle and seat replacement.

Remove the carb, and then remove the float bowl. Check the float bowl jet (which is the bowl screw) and make sure the jets both horizontal and vertical are clean and open. Tip the carb upside down and remove the float pin and float with needle attached. Look in the float needle passage and you should see the red float seat at the bottom of the passage. This is where a #5 crotchet hook would come in handy as you need to remove this seat. If you have no hook, but compressed air, you can blow through the fuel inlet and try to pop the seat out. Put your thumb over the passage to prevent the seat from flying who knows where. No air or hook try bending a stiff paper clip to dig the seat out.

I would either give the carb a good 24 hour soaking or have it ultrasonically cleaned at this time.

With the seat out clean the passage way with carb cleaner. Now you must find a drill bit slightly smaller than the passage way, to be used to press in the new seat. Apply a very, very small amount of a very light lube to the new seat. 3-1 oil or lighter, to help seat it better. Carefully insert the new seat in the passage way with the rings on the seat down toward the carb body. Slowly and carefully force the seat down with the back end of the drill bit. Once it is seated, check to see that it did not flip and the rings are up. Next check to make sure that the float does not have any liquid in it. If it does, replace. If everything looks correct, attach the new needle to the float and install with the float pin centered. It everything is correct, the float should seat level to the carb body, when looking at it upside down. If everything looks good reattach the float bowl, making sure that both the bowl gasket and the nut gasket seal properly. Reinstall on the engine and test unit. Remember to have patience and take your time. Good luck, but I don't think you'll need it.

PS: On the side of some Tecumseh carbs you will find a plastic cover. Under this cover will be an idle jet. Remove it and check to see that the jet is open both horizontally and vertically. You should be able to push the old float needle wire through the vertical opening.

Thanks for the detailed writeup! I found a part online (see attached photo) — it looks like it includes a full carburetor assembly along with gaskets, mounting bolts, and an intake gasket/collar, rather than just a needle-and-seat kit.
Would this be a suitable substitute for the needle-and-seat rebuild you described (part 631021), or is it better to stick with just replacing the needle and seat on my original carb? I don't want to buy the wrong part or overcomplicate this if the rebuild kit would work just as well.

If that's the factory carb, replacing needle/seat/seals avoids issues with questionable clone carbs. However, carbs are available, and I've had pretty good luck with them, even Amazon. From Amazon, I look at the reviews. I want to see mostly good reviews, and hundreds of them. I don't want to be the first to buy a carb off amazon. I also want something on Prime, that I can have in a couple of days. That way I'm not waiting for it to come from China. Several knowledgeable guys here say the HIPA carbs are decent.