Sometimes Hillbilly thinking pays off. for Carb 054 cb400f 1976, and those similar in design.
Scenario: carbs are in stages of corrosion that require overhauls.
This works for all but the most serious corrosion stuck jet holders, without having to remove the slide, and locked link arm set,which can be tedious time consumer with its own added risk of link arm set damage or lost parts. If checking or changing needle position or solidly stuck jet holder, then the manual instructions would possibly be a better way.
Notice even when getting a carb project that's been gummed up and corrosion covered, when slide caps are removed it's usually in the same condition as it was leaving the factory, it's the only piece of carburetor that is not exposed and nor subject to environmental deterioration.
The advanced tool can be found in most homes/garages/kitchens or any rooms. 2 stroke fuel line repair, automotive vacuum lines, insulated electrical wire, taped bic pen ends all will work. To find out if the jet moves any at all, your little finger should reach the top of the jet to see if it budges, but then stops when it's flush with the venturi. If it's fairly loose but you can't get it the last few mm's. use a toothpick to put in the hole from the bottom and wiggle it, just don't try to wedge anything in it to grip it. The tooth pick can get a grip by slight angling it.
1. Find the size fuel line that is just a fraction smaller than the jet holder diameter, cut off a short section of appox 1/2" to 5/8" long, or strip off a solid length of wire insulation, or the tapered pin tube (which is harder material to be careful with.)
2. Cut 1 slice through 1 side of the tube, the slice can be as wide as the needle, for easy removal.
3. With the slide in the upper position (either block the throttle open or take the return spring off,) reach in the intake side and non forcefully put the tube around the needle, the bic if chosen has to have a slot cut into 1 side to fit around the needle.
3A. check the bottom of the tower where the main jet was for corrosive debri and clean out before step 4.
4. With the removal tool in place and the jet holder given a good squirt of penetrant irrigation, lower the slide and watch the removal tool making sure it doesn't fit inside the taper jet holder top, see that it fits over the top of the jet holder and still will travel into the jet holder seat, and that it doesn't bind going into the jet holder seat. If the tube is too flimsy go with a stiffer fuel line/vacuum tube or shorten it.
5. If the jet moves any at all, then it should come out fairly easy. Or spray some more penetrant spray.
6. When enough emulsion tube extends out of the bottom to pull out by hand, then stop and gently reach in with a pair of tweezers, or small needle nose pliers on the intake side of the now raised slide and remove the rubber tube. Or a popsicle stick modified to push the rubber tube off the needle.