Farmall 350 carburetor help

I'll try to keep this as short as possible, but in short I'm dealing with a PIG RICH condition after a carb rebuild.
Recently purchased '57 350, ran pretty well when I dragged it home. The stand pipe off the manifold had been goober brazed
at some point and broke loose when I pulled the muffler off, and carb was a little leaky, so I pulled it all, put on a new
manifold and gaskets, set valves, and did a complete rebuild on the carb, including throttle shaft bushings and a new float.
Soaked in Berrymans for a couple days, sprayed all passages with carb cleaner, and blew everything out with air for cleanup.
Put it back on the tractor and it was clearly rich with black smoke at idle and throttled up. New plugs were installed
before startup and they were black after a short run, def fuel, not oil. Idle air screw changed nothing at idle, all the
way in and all the way out, no change in RPM or richness. Main high idle screw turned all the way in to half turn from
seated did nothing to help.

I pulled it all back down and assumed I still had junk in carb passages somewhere. Into the ultrasonic cleaner for a good
12 hrs. Got quite a bit of black crap out of it and figured I had it licked. I did compare the main jet this time around
and noticed that the old jet had 3 equal sized sets of holes, whereas the new jet had one hole (closet to the threads)
larger than the other two. I called the provider of the carb kit and he confirmed that the proper jet for the 350 should
have one pair of holes larger than the other two, so I left the new jet in and assumed the trash was likely causing bypass
of the idle circuit and creating my rich condition. Put the carb back on, same result.

Float was set to spec (1-5/16) with machinist measure in 64ths, throttle body upside down, no gasket, checked both sides on
the float to make sure they were equal. With the tractor off, gas flow open, there was no gas running into the bottom of
the carb bowl so I know the needle/seat was doing its job. However, on the 2nd rebuild I did find that if I shut the
tractor off without shutting off the gas first I would see a little gas spill down and run out the weep hole in the bottom
of the carb. I found a spec for checking the float externally so I set up a clear tube off the carb drain. Spec showed gas
should come up the clear tube to within 9/16-21/32 of the carb parting line...mine was 3/8 from the parting line....damn
near a 1/4 too high! Left sit for 15 min and it never climbed, confirming needle and seat working.

How could I set the float dead on and have the outside level appear to be so far off? How far should I tweak the float to
try to correct this? Surely not 1/4... Should I be looking somewhere else? Is the main jet a concern to anyone? Should
I put the old jet in or just monkey with the float first? Any thoughts/suggestions greatly appreciated.

Since it was running before you "fixed" it it would seem the old float was intact?

As a test I would put the old needle and seat and float back in and see how it runs and what that does to the "externally measured" gas level in the float bowl.

Also be SURE the venturi is in correctly (SOME can be installed wrong) and be SURE the gasket ports are the same as the old one around the venturi that are part of the bowl vent system.

I appreciate the quotes around fixed...one step forward, 10 steps back! I did save the old float/needle/seat so that is an
option that I don't mind trying. And the float seemed to be dry so I don't mind putting it back in. Are you hinting at the
weight of the new float being off enough to create an issue, or just maintaining the same float height? The float came from
Steiner...not sure if that's a good thing or a bad thing, but I certainly didn't buy a $10 Chinese kit off amazon.

I'm not sure how the venturi could be installed wrong short of upside down...which would be interesting to say the least. Any
further elaboration there? And the old gasket of course came off in multiple pieces and went in the trash, but I assume you
are speaking of the two small holes near the venturi? I have a few spare gaskets around for my 450 as well, one from Steiner
and one from Marks's Carbs and they are exactly the same as what came in the kit for the 350, which I assume is correct.

I would try adjusting the float level 1/8 - 3/16 down from where you have it. If your idle screw is not responsive you need to clean more. You may have done this but it is not mentioned, you need to poke through every passage with a small wire or torch tip cleaners are best. Squirt with carb cleaner then followed with a shot of compressed air. Two or 3 times on each passage. Having the small brass tube projecting off the carb top clear is imperative to good idle. Picture is from a IH M repair manual which uses basically the same carb.

First of all, the main jet is pressed into the body of the carburetor and the adjusting needle has to be able to contact it when screwed all the way in.

It sounds like you are calling the nozzle as being the main jet. And if it ran decent before, put the original nozzle back in. Those kits are often full of the wrong parts. No way of knowing if the nozzle you took out was actually original but if it ran decent before I would sure use it over that new one with different hole sizes.

Make sure the idle jet is not damaged. There again , if old one was ok, I would use it unless you can measure new one to make sure it is same size as old. Very tiny hole in that jet but there are number 75 74 and 72 used which all run in the .025 size range but different.

I would bet someone drilled out the main jet but you can still adjust it to run decent with the adjusting screw. Should be able to kill the engine dead dead dead by screwed it all the way in. If not, something is radically wrong.

Fuel level , well just make sure float is set at that spec in illustration. If it doesn't run over while standing with fuel at tank turned on it is ok.

I don't use kits, I replace parts as necessary individually.

That's the same image I was operating off of to check my fuel height, currently measuring 3/8. ...small brass tube projecting off the carb top--are you referring to the idle jet? If so, this was screwed out and replaced with a new idle jet.

Sorry for the terminology mix up Pete, I was indeed referencing the nozzle.

Regarding the idle jet, I ran the replacement in the first attempt (marked 72) and put the original back in on the 2nd try (not marked)...same result with both.

I understand what you're saying about the kits, but where do you get reliable individual parts? Like everything else in the world, quality isn't what it once was.

So you are of the thought that even though high, the float level likely isn't the issue?

Fuel still has to go through the main jet so you should be able to take the black out of the exhaust at high engine speed regardless how high the float is. Not saying the float level being hisgh is right, just saying it would have to be running over (leaking) out when shut off to cause idle problem and black at high speed.

Understood. Thank you for the reply

Have discharge jet hole size wrote down but not going to look for it now. From what I remember a 361525R92 carburetor has all 3 sets of holes .052 to .053.

Have you left the air hose to the carb off when
trying this out??
Sounds like you might have a restriction in the
air cleaner/ pipe/ hoses going to the carb.
Jim

I can agree that you can get bad parts in a new kit. Or sorta the right parts. I rebuilt the carb on my SMTA. Got a new kit. Tore the carb down three times because it was starving. Thought I missed something while cleaning it. Took the carb off my W-9, the motor ran great. Pulled my hair out until it was suggested here to compare the nozzle from the W-9 carb to the new nozzle. Big difference! The center passageway was smaller and the three pairs of holes were also smaller. Once I drilled the new nozzle out to match the W-9 nozzle, magic, it ran great.

I can agree that you can get bad parts in a new kit. Or sorta the right parts. I rebuilt the carb on my SMTA. Got a new kit. Tore the carb down three times because it was starving. Thought I missed something while cleaning it. Took the carb off my W-9, the motor ran great. Pulled my hair out until it was suggested here to compare the nozzle from the W-9 carb to the new nozzle. Big difference! The center passageway was smaller and the three pairs of holes were also smaller. Once I drilled the new nozzle out to match the W-9 nozzle, magic, it ran great.

Thanks for the reply Jim. Initially I was running though the cleaner, with fresh oil, but more recent testing since the second go-thru on the carb has been drawing air straight in to the throat of the carb, partially hoping it would lean it out a bit for diagnostics, partially so I could make sure the float wasn't overflowing

Got a little time to mess with this yesterday. Returned original float/needle/seat as recommended, checked height and it was dead on spec, installed on tractor and checked float level externally as before, 1/16 difference from having the new float/needle/seat installed (now 7/16 down instead of 3/8, recommended spec 9/16-21/32). Ran tractor, same result.

Back apart, tweaked float 1/8 (new external level 1/2, still a bit high), replaced idle jet and discharge nozzle (main discharge jet per my IH manual...trying to get my nomenclature in line) with originals. Note differences from original and replacement nozzle in original post. This seemed to lean the tractor out, less to no black smoke until throttled up quickly, as expected, but tractor is still running rough and the idle air mixture screw still does nothing, and idle speed is still too fast with idle stop backed all the way off the throttle shaft.

Turned the fuel adjusting needle valve all the way in to seated with the tractor running 3/4 throttle and the tractor keeps running, which is very confusing as this appears to be the only entry route for fuel into air. Pulled out the replacement needle valve and stuck in the original, same result. Tractor clearly leans out a bit when I do this, but continues to run without a huge noticeable change from seated to 5 turns outs, all this with the tractor up to temp and 3/4 throttle.

Sooo....perhaps there is still some gunk despite what I consider to be a VERY thorough cleaning, and otherwise, I'm lost until you smarter folks make more suggestions. I did run up to the farm today and stole the carb off my parts 350 (which is complete, in good running order, and probably too nice to part), and I will slap it on and see how that behaves, but likely will be a few days before I can get to it. Thanks again for any and all help!

My H was rebuilt. It ran flawlessly before it left and came home with no noticeable issues, and then I noticed a stumble that I couldn't tune out via carb adjustments after multiple removals and teardowns. Turned out to be a worn distributor rotor. The wear inside the plastic rotor was enough to throw it off by 3. Verify the timing and tell us what you found. Since you sealed up possible air leaks, other variables can come into play.