TE20 Carb/manifold gas problem

So I've recently done a bunch of work to the TE20. Reseated the heads. Cleaned it inside out. Put it together last night and worked a charm. Just have the rad to put on. No backfiring. No spluttering. Was great. This morning I went to try it and the starter got red hot (like it does when the battery is flat). Charged battery. Great. But it still wor start.
It turns over like it should with no problems, but it's throwing gas out of the carb/manifold gasket. Ive adjusted the carb (Zenith 24T) to specs. Slow running jet to 1 turn out. Main jet to 1 1/4 turns. I don't have the choke on at all.
Any suggestions as to what it may be? Nothing changed in 8 hours and it's doing this!
Thanks in advance.

Is it dripping fuel out the carb, like the needle/seat is not stopping the fuel from overflowing the bowl? If
so, there is probably trash, rust, holding the valve open.

Is it backfiring out the carb? Check for loose distributor mount letting the timing retard.

Is it blowing compression out the carb? Look at the valve train, tight valve, stuck valve, dropped seat,
broken spring, bent pushrod...

I gave the carb a clean with carb cleaner before it went back together. Made sure everything was in top shape.

It only blows a bit of gas out the gasket when it's basically on its last hurrah when I take my finger off the starter switch.

I know it's not the valves or there related as I've ground them all so they seat 100% and cleaned the system before replacing it all.

The only thing I can think of is the jet not being seated right or perhaps damaged when I took it apart for cleaning. The worst part is the tractor hasn't run in many many years so I may be digging myself a hole haha

Plugged fuel filter. From the inlet pipe inside the tank to the carb elbow. Start at the elbow and work up to the tank.

Steve is most likely right , unless the fuel tank was purged as well, grit has probably jammed the needle a little .
Before removing the carb yet again [ yes I've been down that path ] try this . Take a largish screwdriver and give the float chamber a decent rap with the plastic end . Be careful not to get too vigorous as it's only diecast alloy . Nine times out of ten this will dislodge any grit after one or two goes .
There are hidden filters in TE20 tanks , these look like an upright cigarette and are attached to the top of the fuel tap assembly . They are made of a fine bronze mesh that disintegrates over time and fills the tank and valve with lots of fine grey/ green grit . Once a tractor is worked on it usually disturbs these bits and they make their way to the carb causing problems similar to yours .
If you want to, the remnants can be easily removed , there is no need to replace them , just strain your fuel when filling .

It's normal for an updraft to drip a little gas following a failed start. How do the plugs look? Wet, black would indicate too rich.

Too much Choke would cause it to drip if the engine didn't start. The Float itself also needs to be adjusted so that the fuel level in the Carburettor is not be too high or too low. As has been said, it could be the Needle and seat above the Float that is sticking or has grit in it and a bit of a knock on the Carb will often disturb it sufficiently. If you have problems with this, you should consider fitting a filter to the line from the carb It needs a substantial filter that requires little or no pressure to allow the fuel through, a small filter may not work as the pressure of the fuel from the Tank needs to be higher. There is a small filter in the elbow on the end of the fuel line that screws into the Carb. NEVER blow the fuel from the Carb side of this elbow and don't try to probe it.
The plugs should not be wet at all, that would mean that they are not firing. The colour will vary depending on the fuel, often they are black or grey now. The Carb setting you used is only the initial setting to get the engine started, the Carburettor can only be adjusted correctly when the engine is HOT (not warm) This is how the engine runs when it is working, it should never run cool. If it does run too cool then check the Thermostat too in the Top Hose
I can send you the correct way to set-up the Carb if you need it. Have you cleaned out the Air Cleaner as well, these gradually block up and this causes the engine to choke itself and could also cause your problem. You say that it is a TE20, are you sure that it is and it isn't a TEA20 which would be slightly different on the information that you need
John(UK) [email protected]