So I'm rebuilding another Stromberg 97 but one of the idle jets is not cooperating . The screwdriver slot is/was buggered up, I've heated and soaked but no luck. I'm reluctant to drill because I'm afraid of wandering off and messing up the carb body. Anybody know who can fix this for me?
Small EZ-out. If you have to drill a hair larger, the jet hole will center the drill bit, no worries.
Try hitting the jet straight down with a drift. Give it a good shot. The shock will tweak the threads enough to turn it out. If the slot is bungered, use a screw driver to shock it. I used to chuck bodies for stuck jets. I have gotten dozens out with the drift and never loose one now. The jet is F'd anyhow. I do 1100's,2100's, 2150's, 4100's and the like. I have never cracked one. If the jet is truly stuck, the body is junk anyhow. There have been some I have really laid into. They can take a surprising shot. Mike
Suggested procedure. Measure the thread on the other jet (I don't remember them without looking. Determine the drill bit to use if you were going to drill a hole, and thread it using this thread. Place the carb body in a machinist vise on a drilling machine, and CENTER the drill bit over the jet in the milling machine. Measure how far you need to drill, and drill (SLOWLY) this distance. Now remove the body from the vice and turn it upside down to allow the idle tube to fall out. Use a tap of the correct thread to chase the threads in the body. NEVER attempt to use a not-so-easy-out on brass. Next step is an EDM machine to remove the broken not-so-easy-out. Good luck. Jon
I have had success with just this on 94 and 97 carbs with stuck jets. I use the canned air for blowing out keyboards and computer equipment, only i turn the can upside down and blow it directly on the jet that is stuck. It will freeze the jet and cause the metal to shrink just a hair, and while it is cold, grab a screw driver and turn it out. id give it a try before I go drilling any thing.
Shift Wizard - no offense was intended. Not-so-easy-outs used in brass tend to expand the brass more tightly against the wall; and very easy to break a small one. I have some diamond tipped burrs that, with effort, can remove a broken not-so-easy-out. I had to buy the burrs, as when I was still restoring carburetors, I had more than a couple Carter AFB's come in with a broken not-so-easy-out stuck in a main jet. One, on a pretty rare Chrysler AFB, had damaged the floor of the jet well. We had to have the floor mig-welded, filling the entire jet area with aluminum, and then re-machine to specs. It is memories such as this that leave lasting opinions! These things work fair well in steel, especially if one can drill the pilot hole, then heat the offending bolt, then use the easy-out. Jon
Has anyone ever drilled a hole in a spark plug that was larger than the Easy Out, then dropped the Easy Out through the hole, straight into the cylinder? Yeah, me neither
A solid carbide or carbide spade was our broken tap/easy-out go-to when I worked at a machine shop. A good carbide will drill into most stuff. (Break that off in there, and you'll be looking for EDM.) That, or the old "weld a nut on and wind it out" (if you are brass nut and TIG rich). The cost of the job was usually based on the value of what you were saving rather than time. Classic "don't call them yet, they don't need to know how fast we fixed it" thing. As far as center drilling with a tap drill, done right and you can pull the thread out like an old heli-coil. May not even need to have the odd tap on hand. I've seen Jim (the Machinist) hand drill and pull threads. "Not I" said the rabbit. Most of these threads are really fine, the difference between pulling the threads out and having to totally re-tap the hole is probably ~1/32". When tapping, try to get all of the brass out. The tap will probably fuck up cutting between the aluminum-ish carb body and brass threads. If you do the drift thing, you know you are on the right track when the drift is denting the jet. Deform the threads slightly and break the corrosion's grip. Good luck, whatever path you take ! Mike
None taken, Kemosabe. I figure that you eat stuck jets for breakfast every day. So even if once upon a time I successfully removed a stuck jet in a dumb, risky way, I would never argue with your wealth of experience. Yu' da Man!
I'd try several heat and cooling cycles then follow what carbking suggests but with a slightly smaller reverse drill. Sometimes you get lucky and it spins free. Then if needed you can step up the drill to the minor diameter of the thread. But as he says keep an eye on the depth.
A thank you to everyone , after heating, bad words, PB blaster, more heat, I got it moving by taping on a shoulder with a punch and she finally gave in. Again thanks, another 97 saved from the scrap bin.
I have had many similar problems with Stromberg carburetors. The heating and cooling cycles will usually do the job. I also use "Kroil" after the heating cycle. Another thought, put the carburetor body back on the base with the screws, mount the assembly in a vise and use a hand held impact screw driver to un-screw the idle jet.
That was more less what I did, I was about to use a hand held impact but using a punch to unscrew the jet did the trick.
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