Farmall H Carb Rebuild

I like to thread the "needle" adjustment screw into the brass packing nut, and then slip the packing gland onto that needle, and then install the whole assembly as a unit. I also like to have the fuel bowl drain plug or petcock out of the carburetor. This will allow you to look through the drain plug hole and see how that adjustment needle is lining up with the small, brass metering jet inside of the carb.

The packing nut will have to be threaded in to the point where it starts to get snug or you won't be able to thread the adjusting screw in far enough to bottom out in the metering jet, and you also need to make sure that the adjustment screw DOES NOT bottom out while threading the packing nut in. Another reason to look through the hole where the drain plug goes.

Also, the packing nut can very easily be cross-threaded when starting it into the threads in the carburetor, and it is almost impossible to remedy the damage that occurs if that happens.

Once you get the packing, adjustment screw, and packing nut all in place, and the adjustment screw is properly set, then you can snug that packing nut down to the point where you CANNOT turn the adjustment screw with your fingers. This should be tight enough, but if it drips a bit of gas later on, just tighten down the packing nut some more, BUT, make sure the adjustment screw does not turn with the packing nut.

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