Farmall H running rich

Hello,
I have a 1949 H that is running rich and gas fouling the plugs, particularly #1 and 2.
We recently put a new after market manifold on it.
Also it has had new plugs, points, and condenser. Also a new carburetor fuel screen put on it.
Any thoughts as to why it would be gas fouling the plugs and running with a bit of a miss.
Thanks,
YVC

A few things come to mind.
Air cleaner full of ice and dirt.
Choke butterfly not open all the way
Main jet set way to open so running rich for poor adjusted carb.
Carb in need of a rebuild.
Float sticking or needle not closes off gas flow like it should

Close that main jet adjusting screrw as Old suggested. Hal

You may have seen my H carb procedure before, maybe not. THis might help;

Make sure the float isn’t sticking or touching the insides of the float chamber. Some previous advice was to use a Dremel tool and smooth the insides of the float chamber so the float doesn’t rub or touch. Pretty important.
Set the float so the top of it rests 1 27/32" above the flat surface of the float chamber.
Initial settings are as follows to get it started;
Main fuel adjusting screw, big screw facing down at an angle, towards the rear, at the bottom of the carb; 2 1/2 to 3 turns open. This main screw turns clock-wise for leaner mixture. [This screw adjusts fuel.]
Idle air-mixture screw, smaller screw facing forwards, on upper left-hand side of carb; 1 to 1 1/2 turns open. This idle screw turns counter-clockwise for leaner. [This screw adjusts air.]
Idle speed screw, faces outboard, at the top of the carb; set for 450 rpm, and make sure the governor correctly engages in the slot. [This screw adjusts RPM’s.]
Final settings are determined as follows;
Get the engine warmed up, and idling.
Turn OUT the idle air-mixture screw until rough running, then turn in until it idles smooth. (Mine is set at 1 turn open.)
Rev it up, wide open, warmed up, then turn the main fuel adjusting screw IN until rough, then out til smooth, then 1/4 turn to 1/2 turn further out. (Mine is set at 1 turn open. Other advice has been to set it at 2 1/2 turns open for pulling implements.)
Should rev up smoothly and evenly.
Too Lean = stumble, sputter, damaged melted plugs.
Correct = tan plugs.
Too Rich = back smoke, black sooty plugs.

Here's the main adjusting screw on a Toro mower with B&S engine. My Wards tractor has the same carburetor. Hal