Problem connecting wire to Sisson choke on 48 DeSoto

[MarcDeSoto]

What do you do when the screw that fastens the Sisson choke wire to the choke        won't tighten down?  I tried to put in more washers, but that didn't help.  Should l just solder the wire to the choke, or is there a way to make the screw tighten up?  

[DonaldSmith]

It requires a very short screw, or the screw will bottom out, grounding the wire.   Maybe your screw is too long.  You can check with your multimeter to see if the screw is bottoming out and grounding 

[Dodgeb4ya]

?

[MarcDeSoto]

I checked the length of the screw with the Parts List and it was correct.  I tried putting extra washers on it to shorten it more, but the screw still spins.  

[joecoozie]

Are you sure it's the screw turning and not the "insert" in the choke?

[MarcDeSoto]

No I'm not.  I took the Sisson off, but you can't see anything because of metal in the way.  I'm thinking maybe thread lock glue to hold it?  

 

https://www.homedepot.com/p/Permatex-0-20-fl-oz-High-Strength-Threadlocker-Red-Gel-27005/205905907

Edited January 10, 2023 by MarcDeSoto

[MarcDeSoto]

The Threadlocker didn't work, but that's not what it's supposed to do anyway.  I think the only solution other that buying a new Sisson choke is to solder the wire terminal to the screw.  

[MarcDeSoto]

This doesn't look like a 46-49 Mopar Sisson choke to me.  It has the wrong part number for one.  At that price, I think I'm going to keep mine and solder the wire!

 

https://www.ebay.com/itm/185273325771?hash=item2b232698cb:g:5xMAAOSwIlVh8~3j&amdata=enc%3AAQAHAAAAoBENUM453hVdVFseowKsLoSRT22buaep20Sfzbi4860ZK8%2FqrGX9PMBXUxMncJf1%2BuiOYPGk%2FtfPy2%2BC12bWchEKTXyFadSFNlihZJ%2BJLayrbTCtZh%2BZwKBfuCm49beemkbzU%2FS2sfpvKrx0AwjvIGkilCYidAuF0P1OT%2FLEqZe3YPRhdiYBZI%2BHT35GgV4O7WbDAuLjHWyXma99zHNeu4g%3D|tkp%3ABk9SR7LJ5qGzYQ

[joecoozie]

The one on Ebay is for an 8 cylinder 

This is the one for a 6 cylinder

[MarcDeSoto]

I tried to solder the wire to the screw, but it just wouldn't stick.  Soldering isn't welding I guess.  Maybe I can super glue it?

[wagoneer]

1 hour ago, MarcDeSoto said:

I tried to solder the wire to the screw, but it just wouldn't stick.  Soldering isn't welding I guess.  Maybe I can super glue it?

 

 

JB Weld will do the trick.  But once you do it that's it. No moving/tightening.

[wagoneer]

sounds like either the screw threads or the sisson threads are stripped. Start with a new screw of same thread sizing. If that fails then it's likely requires fresh threads in the screw hole. 

 

Run it through same size tap and use a new screw. Failing that,  re-cut the threads ever so slightly larger to get a fresh hole.

 

Painful but less permanent than JB Welding the wire to the sisson which won't let you have much flexibility for adjustment in the future. You should be able to find a small enough tap once you identify the specific thread size.

Edited January 10, 2023 by wagoneer

[Sam Buchanan]

If the threads are just wallowed out you might find a metric screw that is close enough in size to cut new threads as you force it in the hole. Soldering or JB'ing should be your last resort.

[kencombs]

Loctite Form-a-thread may work.  Not cheap, but if it solves the problem....

[desoto1939]

Yes you can weld the wire to the contact point and then make a connector so that you can remove the lead in wire to the wire that is permanetly soldiered to the sisson choke. If your car is not going for points judging then this will not harm anything.  I have used the removable Locktite on several other threaded screws and it hold fast until I break the connection. Might also try the metric screw repair.

 

Rich Hartung

 

[kencombs]

2 hours ago, desoto1939 said:

Yes you can weld the wire to the contact point and then make a connector so that you can remove the lead in wire to the wire that is permanetly soldiered to the sisson choke. If your car is not going for points judging then this will not harm anything.  I have used the removable Locktite on several other threaded screws and it hold fast until I break the connection. Might also try the metric screw repair.

 

Rich Hartung

 

I should have been more clear in my posting.  The product I mentioned is not the 'removable locktite', but one that  molds new threads into the hole and around the screw.  The screw/bolt is installed and removed as normal but that Locktite creates a new thread for it to enter.  Not quite as strong of course, but works for most light duty jobs.  No head bolts, manifold bolts etc.  Search for 'form-a-thread'.

 

 

 

[MarcDeSoto]

All good ideas here!  Thanks.  I cranked my engine to see if the Sisson choke would close the choke.  It did, but as soon as I stopped cranking the choke fell back to slightly open.  Does this sound normal?  

[38DeSoto]

Yes, the sisson choke will fully engage while engine is cranking, and once you 'release' the starter the sisson choke will go to the position the internal heat sensitive spring is at.  When working properly, the engine should run smooth and not stall after start up. 

[MarcDeSoto]

Special thanks to Wagoneer who solved my problem!!!  I went to HD and bought a bag of the same screws No. 8 32 thread X 3/8 long.  I tried to screw in the new screw, but it wouldn't go in.  My loose one would screw in easily.  So I tapped the threads for a few threads into the Sisson choke.  Now I could start screwing in the new screw.  It was tight fitting, but that was good.  I attached my wire coming from the stater solenoid, and I screwed the new screw all the way home.  Now it's as tight as can be!