Thermoquad questions

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One last question:

After adjusting the air valve it springs right back when pressed down with the linkage to the diaphragm disconnected, but returns much more slowly with it connected due to the friction of the linkage through the slot in the tab connected to the air valve. I noticed there is a sort of ring attached to most thermoquads here which I don't have. Is my case normal/ok?
 
This is the part I'm referring to (not my specific carb in the pic)
Screen Shot 2023-10-11 at 10.18.03 PM.png
 
Some pics would help.

Seems odd that the AV spring would be in the f/bowl. AV would have to be removed [ 2 screws ] to slide the AV shaft far enough for spring to drop out. There is no need to remove the AV during cleaning/maintenance. ??
So check that AV mounting screws are tight.
 
Pic in post #27. You need that 'ring'. It is a very thin washer that positions the connecting rod to the dashpot in the correct orientation.
 
I should add: I have run TQs with the dashpot disconnected. Wind up the AV spring to 2.5-3 turns. You may get a slight flat spot when the secs hit, but often not.....
 
Bewy said:
Some pics would help.

Seems odd that the AV spring would be in the f/bowl. AV would have to be removed [ 2 screws ] to slide the AV shaft far enough for spring to drop out. There is no need to remove the AV during cleaning/maintenance. ??
So check that AV mounting screws are tight.
Click to expand...
I had that happen once. When I was adjusting the airvalve with two screwdrivers (one to hold the inner and outer lock ring) one of them slipped and the spring went "waang". It dropped off & went into the bowl. Probably what happened to his unit as well.
 
No, you need the washer which is clearly visible behind the circlip in post #27. It is about 1/2" OD, hole fits the link. You can 'make' a washer using thin steel to the shape in post #27. OD is not critical & it does not need to be perfectly round. The purpose of the washer is to stop the circlip getting caught in the slotted arm on the end of the AV shaft.
 
Make absolutely sure the X-Ring gaskets are in place in the fuel well or you will have a massive fuel leak. This is the only really big issue with TQ's that I have seen.
 
And along with RLF, make sure they are the actual X rings and not the flat style o rings most kits have.
 
I had to install a heavier spring on the air door of mine on a 340 with .528 solid cam to prevent bogging with a 4 speed. I kept tightening the original until I almost had the bog out and the original spring broke. I got the heavier spring out of one of those assorted spring blister packs at the parts store. I was using a Thermoquad from a 440 if that matters. It ran great after that little modification.
 
Post #41. I have never found a difference in AV springs in nearly 50 yrs of working on TQs. Never seen one break either. That is Ford, International & Mopar TQs. The were different AV dashpots.
 
The Carter rubber X rings that go in the bowl. Stopped using them in 1980. Or was it 1981.....

I find they are too soft & do not seal reliably long term. I just use ordinary O rings, fuel resistant. 7/16" OD, 1/16" wall thickness [ 11mm, 1.5 mm ]
 
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