H carb and idling

Anonymous-0

Well-known Member
Cleaned a carb on a H for a friend and it doesn't seem to run as fast as mine and when you idle it down it dies, where as mine just idles really slow. The tractor was all gummed up with varnish in the sediment bowl and when that was clean I could only get it to run on brake cleaner shot into the intake of the carb. So I took the carb off and cleaned. Runs now other than the speeds mentioned earlier. When and took another carb off for another friend to clean and he said his runs the same as the previous mentioned H, but his other one runs like mine does. So what am I missing. thanks chris
 
My carb adjusting procedure I developed 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.
 

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