Carter Themoquad specs

[73Coupe]

I am rebuilding the Themoquad carb on my '73 440 and the rebuild kit I got at Napa did not come with instructions or specs. Looking for specs mainly for float setting and other key things before I put this back together. I do not have a factory shop manual yet. If anybody has any specs handy or could direct me to some leads, it would make my day!

Thanks....JT

 

[Mr C]

Scroll down to the Service Information section and the links there.

http://www.carbkitsource.com/carbs/tech/Carter/TQ-index.html

 

[73Coupe]

Much appreciated, Mr. C! That's a good site to bookmark. Also found some other good stuff on there for my upcoming WCFB rebuild project on another car.

 

[70bigblockdodge]

3 things to watch for seating the square o rings at the bottom of the float bowl in the wells where mains are, if these leak they cause a leak into the primary venturis, you need to check the weight of the phenolic floats they seem to hold onto stuff that is/was in the gasoline, if too heavy you will never get fuel level right it will always want to have a high level and flood. Lastly is easy, make sure the center between the secondaries is not broken cracked or missing. Good luck.

 

[73Coupe]

3 things to watch for seating the square o rings at the bottom of the float bowl in the wells where mains are, if these leak they cause a leak into the primary venturis, you need to check the weight of the phenolic floats they seem to hold onto stuff that is/was in the gasoline, if too heavy you will never get fuel level right it will always want to have a high level and flood. Lastly is easy, make sure the center between the secondaries is not broken cracked or missing. Good luck.

Thanks....I wonder how to determine if the floats are good? The manuals and specs in the above link mentioned didn't list weight info, however they had float part numbers which led me to ebay where floats are coming out the ying yang. Also brass floats might be a good substitute...
http://www.ebay.com/itm/CARBURETOR-...Parts_Accessories&hash=item19e4ad6fb6&vxp=mtr

EDIT: Found plastic float spec weights from this page: http://www.carbkitsource.com/carbs/tech/Carter/pages/tqguide-Vaanth.html
Floats:Early TQs had brass floats. By 1975, all TQs used nitrophyl floats. Over time, the nitrophyl floats can absorb gas and sink, allowing fuel levels to be too high. The floats should weigh 7.4-8.0 grams. Carter no longer services brass floats, but several sources are available (see the Service Parts Information section).

 

[70bigblockdodge]

I was going to try and make a set of brass floats from edelbrock ones and the anchor point of the TQ. Nowadays with the ethanol and such in the gasoline I think it would be worth the trouble.

 

[monaco75]

I was going to try and make a set of brass floats from edelbrock ones and the anchor point of the TQ. Nowadays with the ethanol and such in the gasoline I think it would be worth the trouble.

So Dave, uhh... How much for a rebuild, if I send ya my TQ?? lol

 

[thrashingcows]

I have redone a few TQ's. I have found following the rebuild, and settings to the letter makes all the difference in the world. I have had "reman" units that were so far off that I had to tear them back down and re-set all the factory settings just so i could get the car to run half decent.

Nice to see someone else taking on these old carbs. They are great carbs if set up, and tuned properly....but they do require a lot more work to get set-up. ;)

 

[73Coupe]

Yup, it's good to always start with the factory parts and settings then go from there if necessary - but not too far off.
I sourced all the numbers for the factory jets and rods and will check the pieces to make sure they're correct. If not, new parts can be found in a "strip kit".
I ordered brass floats today to replace the plastic ones.... Carter # 21-249

 

[73Coupe]

Got my new brass floats and put the carb together this weekend!

Now gotta make all the exterior adjustments and figure out the choke linkage, including the vacuum pull-down. There's only one spot on that side for a linkage arm, but I have two that need to be hooked up somehow...

 

[70bigblockdodge]

Could you do me a favor if you still can and hold the plastic float along side the brass one while the brass one is installed looking straight down. If not don't sweat it. Thanks

 

[70bigblockdodge]

I am hoping to get a air fuel ratio gauge that I put on my letter to Santa. I would love to get one of these really dialed in because I think the fuel mileage with the small primaries and stepped rods could be made very good and you still have a 800 cfm carb.

 

[Ripinator]

Thanks....I wonder how to determine if the floats are good? The manuals and specs in the above link mentioned didn't list weight info, however they had float part numbers which led me to ebay where floats are coming out the ying yang. Also brass floats might be a good substitute...
http://www.ebay.com/itm/CARBURETOR-...Parts_Accessories&hash=item19e4ad6fb6&vxp=mtr

EDIT: Found plastic float spec weights from this page: http://www.carbkitsource.com/carbs/tech/Carter/pages/tqguide-Vaanth.html
Floats:Early TQs had brass floats. By 1975, all TQs used nitrophyl floats. Over time, the nitrophyl floats can absorb gas and sink, allowing fuel levels to be too high. The floats should weigh 7.4-8.0 grams. Carter no longer services brass floats, but several sources are available (see the Service Parts Information section).

I imagine our crappy ethanol gas has / would do a number on those plastic floats too.

 

[73Coupe]

Could you do me a favor if you still can and hold the plastic float along side the brass one while the brass one is installed looking straight down. If not don't sweat it. Thanks

Aw man, I already closed up the carb. If I take it apart again, I'll get some pics. The brass floats are the same length, though, but taller. For my application, they are set to 1" from the bowl cover gasket vs. 7/8" for the plastic float.

 

[73Coupe]

And pics of the final outcome...

 

[commando1]

Nothing is more satisfying than complely tearing down a carb, and having no leftover pieces afterwards.
Nice job.

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[70bigblockdodge]

No problem let us know how it runs.

 

[73Coupe]

Nothing is more satisfying than complely tearing down a carb, and having no leftover pieces afterwards.
Nice job.

Dayam straight, thank you!

Running far better with the TQ installed, just doing fine tuning with ignition system now as outlined in my other thread.

I have a hard time keeping my foot out of the 440 on the freeway. :-D

 

[73Coupe]

Update: 20k miles on it since and have had it off the car several times with accelerator pump problems. The pump seal kept coming off, so i got myself some replacements at my local carburetor shop. They have been lasting about a month or two each before the car starts stumbling and stalling when I give it gas, and I know it's failed. Then I just put a new one in.
The fluoreastomer rubber cups are supposedly ethanol resistant, but I have noticed they swell up over time. Just enough to make them "stick" to the sides of the pump cylinder and come off on the upstroke. The pics below show how it looks upon disassembly.
Lastly, the plastic retainer started to separate from the shaft, mainly when the engine was started hot. So this time I glued it all back together with JB weld to get me through my weekend travels.
So now, I have ordered a new pump shaft and seal like I have, and a leather-clad shaft. They are the same size from hole to bottom of the seal, so the leather one's going in next! Also, the leather pump features a solid brass shaft and retainer so it's bulletproof.

 

[73Coupe]

Here are the new pumps. A new plastic/rubber one for comparison to the brass/leather. Perhaps the leather version is what came in it originally....
When the current pump gives out next month, I'll throw in the leather unit. And hopefully that'll be the last time I have to pull off the carb for a long time. Runs great, otherwise.