After a tuneup including plugs, wires, cap, condenser, rotor, gaskets, points, fan belt, fuel line from tank to solid line including inline fuel filter and shutoff valve, radiator hoses, fresh coolant, oil/filter change (Rotella T 15w40), new oil drain plug/gasket, top off transmission fluid, new shifter boot, new oil pressure guage, the ford 9n / 2n still needs starting fluid to get started (warm or cold, 90% of the time). It will not fire without the starting fluid (ether) sprayed into the air intake of the carb.
Next is to check that the choke is working properly. The pull lever pulls in and out on the dash just fine, it rotates the other end just fine, but… ah ha… the nut is not tight at the other end. Tighten the nut and the level won’t pull out at the dash. The carb choke flapper must be stuck. Try to move the flap by hand and it is stuck good. Remove the carb from the tractor and work on it with WD40 and a small ball peen hammer for about a half hour and it moves easily. Put the carb back on the tractor, pull the choke, and it fires within 2 seconds of cranking. No more starting fluid!
Btw…. carb is a Bendix Zenith model