Thermo quad 6138s ?

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flathead31coupe

flathead31coupe

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Can someone tell me if the choke rod and pieces, as well as the fuel pump rod from other tq carburetors are interchangeable... also, does anyone have a picture of a 6138s factory carburetor from both sides.So I can tell what's missing on mine.Thanks.
 
On some other Thermos it is. The accelerator pump arrangement
is somewhat different on most later carbs.
 
GTX JOHN said:
On some other Thermos it is. The accelerator pump arrangement
is somewhat different on most later carbs.
Click to expand...
I looked at a few pictures like the ones I have and it looks like the celerator pump rod is different... On the one I have compared to the ones online.I was curious.I have a few that look like they have the correct rod but i'm not sure... As well as the choke pull off and linkages and things.
 
Only a couple different Accelerator Pump rods.

If it looks right = it probably is the right one.
 
The later TQs have a different casting on the airhorn for the acc pump lever. The casting sticks out further towards the front & the lever used for these is also different. Distance from the pivot to the hole where the 'S' link goes is longer. I believe the connecting rod is also different. The pump plungers are the SAME.
 
This is what I have currently.It is still missing a few pieces.. The second set of pictures is wanna have lane around.Thought I could use some of the.
Choke pieces.... But not sure.

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20240921_173258.jpg


20240921_173246.jpg
 
I'm not sure if it makes a difference or not.But I am not planning on using a choke.. .. Also had a different question, i read that one of the difference being the 6138s is for a 4 speed 340 carb that it has a is richend idle circuit witch allows the carburetor to come to an idle slower for a four speed.. Can someone explain, is it that noticeable when you are at an idle and reving it up and letting it come to an idle
 
I've been looking at a lot of 6138s carburetors online..most of the accelerator pump rods are different, and attach with the rod hook at the bottom and some at the top...need to find a way to see a untouched oem one or some one who knows ...
 
Is a 6139 close enough to help with photos? I have two of those I could grab for pics if you want.
 
The 6138 is for man 340; the 6139 is for auto 340. The same met rods & jets are used in both models. In decades of working on these fine carbs, I have never seen any difference to the idle cct. IFR will be 0.031-033". The difference could be one had a hot idle compensator, other didn't.
At some point, the acc pump rod & pump lever were changed, as described above. Also, with this upgrade, some pump shot is retained so that there is some pump shot added when the secs open. This does not seem to be well known. All the 9000 series carbs I have seen have this feature, but not sure when it started.
 
Bewy said:
The 6138 is for man 340; the 6139 is for auto 340. The same met rods & jets are used in both models. In decades of working on these fine carbs, I have never seen any difference to the idle cct. IFR will be 0.031-033". The difference could be one had a hot idle compensator, other didn't.
At some point, the acc pump rod & pump lever were changed, as described above. Also, with this upgrade, some pump shot is retained so that there is some pump shot added when the secs open. This does not seem to be well known. All the 9000 series carbs I have seen have this feature, but not sure when it started.
Click to expand...
Thanks..I appreciate it.
 
Thanks for.
The pictures I appreciate it.I'm using the stock intake... Judging from your pictures, it looks like the choke pull off. Rod is different on mine and accelerator pump rod is different, but that could be it is the wrong parts on mine... I also don't have the little spring on the left side top on the choke assembly
 
What year or casting number intake? A lot of carbs got goobered over the years. I'm fixing a 9800s right now. Always nice to have an untouched original for reference.
 
I have kind of a rebuild question. The x rings or quad rings that go down into the plastic body of a thermal quad. Do the brass pieces fit down on top of the quad rings. Or inside of the quad rings.
 
No, the X-rings drop into the wells in the bowl to seal the primary extensions on the top housing. What rods appear incorrect? I might have spares.
 
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