[carbking]

Disassembly of screw-in parts on cast iron carburetors

Remove everything that heat can hurt (venturi, springs, etc.); put the casting in an electric toaster over, and heat as hot as you can get it. Now remove, and spot heat the CASTING where the jets thread in (not the jets, just the casting) with an acetylene torch until these areas of the casting are cherry-red. Place the casting back into the toaster oven at maximum heat, leave for about 5 minutes, then turn off the oven, and allow the casting to cool (DO NOT QUENCH).

Remove the cool casting. Often, you can now remove the jet with your thumb-nail.

DO NOT USE THE HEAT TECHNIQUE ON POT METAL!

For pot metal carburetors

Cleaning via either an ultrasonic cleaner, or boiling in water and soap is permissible. Do NOT blast prior to complete assembly.

A zip-lock bag and freeze overnight in your freezer, then apply the spray freeze to the jet. This may need to be repeated, occasionally several times

Make a special screwdriver from a piece of steel bar. Measure the thickness of the slot in the jet(s) to be removed. Now, mill from the end of the bar, leaving a ridge 0.005 thinner than the thickness of the slot, and as tall as the depth of the slot less 0.005 inch.

The flat end of the bar can now rest of the top of the jet, with the ridge inserted into the slot. One can now use pressure against the top of the jet, and rotate. Now possible to use more rotational pressure without the ridge slipping out of, and destroying, the slot.

For those disassembling (or assembling) carburetors with a power valve (a.k.a. economizer valve) with a spring-loaded plunger in the center of the valve (many Strombergs, many Rochester), machine a hole in the center of the end of the bar with a diameter larger the the diameter of the plunger before milling the end of the bar. This will prevent the valve from internal damage caused by a straight-blade screwdriver.

Someone once said a picture is worth a thousand words.

Look at this link, and scroll down to the T109-61 to see a factory tool as described above.

https://www.thecarburetorshop.com/Carter_tools.htm

Jon