DFEV problem

[wetminkey]

So,...my DFEV is not very old, but the threads that secure the idle screw are slightly stripped. And will only get worse,...
I believe that it is because the DFEV came with such a huge spring (on the idle screw - to prevent it from turning when not being adjusted), that adjustment has damaged the threads in the "idle screw arm" (the one that holds the idle screw) that comes off of the DFEVs' main throttle shaft.
I'm not sure that I can replace the "arm" (parts availability), so I think that my best choice is to drill/tap/thread to the next size screw, and replace the spring with a weaker one.
Sure wish that I could add depth to the idle screw threads,...haven't figured out how, yet. ?welded nut?! Formed threads??
Just planning ahead, so I'm asking for any recommendations and suggestions, guys/gals,...watcha got in mind?
I can sure try to get a good pic of the arm that I refer to,...
Thank you very much for any brainstorming. Todd.

[Nut124]

Got a picture of the problem?

If you had the part loose, in your hand, it could easily be modified as needed, I think.

[18Fiatsandcounting]

Doesn't the idle speed screw fit into an inch-long "arm" that extends out from the main body of the carb and is part of the casting? You're right, there is not much meat on that arm, but you might be able to re-tap the threads to the next size up.

Alternatively, the Weber carb metal doesn't look like something that would weld, but there might be an epoxy that you could build up the damaged threads with and then re-tap new threads.

-Bryan

[wetminkey]

You've got it, exactly, Bryan - and, as you state, that "arm" on the DFEV does NOT have much metal,...
One of my "possible solutions" may be the JB Weld Steelstick that I have on my shelf in my garage. I could try building up a 'thickness' on the "screw-side" of the arm, center with a toothpick prior to drying, and drill/tap to the next larger size once it's good and dry. And use a short, weak spring to reduce any unwanted screw rotation, in the future.
I think that replacing the 'arm' would only put-off an eventual fix, unless the giant spring is replaced with a weaker one..
Anybody else see this happening with their DFEVs? Mine is stamped, Spanish-made.
Thanks, Bryan. And nut, I'll try to get a pic, but the carb is in place on a running Spider, at the moment. Planning ahead, right now.

[18Fiatsandcounting]

I could try building up a 'thickness' on the "screw-side" of the arm, center with a toothpick prior to drying, and drill/tap to the next larger size once it's good and dry. And use a short, weak spring to reduce any unwanted screw rotation, in the future.

Todd, I think that is a good first step: Build up a "blob" of JB Weld on the screw side of that post, and then drill/trap for the screw. Slightly roughen up the existing metal before applying the JB Weld, and let it cure completely (at least 24 hours).

The JB Weld might even be "sticky" enough with the screw that you wouldn't need a spring. Or use a layer of Teflon tape. There's not much force on the screw, but you don't want it backing out over time and seeing your idle speed drop.

Another option is two very thin nuts on the screw, on either side of the screw post, and you could do away with the spring. Or, keep the spring but use one such nut on the other side. The downside of these "solutions" is that it would make adjusting the idle more difficult.

-Bryan

[wetminkey]

This is the best pic that I could get - showing the idle speed adjustment screw, and the associated 'arm' that protrudes form the DFEV, to accommodate it.

It's the threads in the arm that are the problem,...
And I believe that it is caused by the heavy spring that came on the screw,...I believe that it causes the screw threads to 'eat' at the threads in the arm.

[18Fiatsandcounting]

Todd, I have to "retract" my previous advice, as your idle screw setup is different than on the DFEVs that I have (after looking at the picture). I think the advice you got on Mirafiori is good, and my suggestions were for a idle screw setup where the screw is tapped into an extension that is cast as part of the carb body, which it doesn't appear you have.

Anyway, carry on, and I hope you can get the screw properly fixed.

-Bryan