fuel adjusting needle.. farmall H

charlie (ky)

New User
ACCORDING TO INSTRUCTIONS, ,,, "SET FUEL ADJUSTING NEEDLE THREE TURNS OFF SEAT." If they mean three full turns, it is almost falling out and gas is leaking.
 
There's fuel adjusting and there's air adjusting. See my procedure below that I compiled from several manuals;
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.
[Note a new float might already be set correctly.]

INITIAL settings are as follows to get the engine 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 as follows;
Get the engine warmed up, and idling.
Turn OUT the small idle-air-mixture screw until rough running, then turn in until engine idles smooth. (Mine is set at 1 turn open.)
Rev it up, wide open, warmed up, then turn the big 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.)

Engine should rev up smoothly and evenly.
Too Lean = stumble, sputter, damaged melted plugs.
Correct = tan plugs.
Too Rich = back smoke, black sooty plugs.
 

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