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Carter carbs leaking into intake manifold

RJRENTON said:
The primary well plugs are located in the void space immediately adjacent to the secondary throttle plate bores at a upward diagonal direction. Sorry, I do not have a pdf editor that i can draw a arrow in your pix. Likewise, the secondary jetwell drillings are EXTERNAL on the sides of the carb shown in your example.
BOB RENTON
Click to expand...

Do you mean the bumps I have marked here? Again thanks for your time

IMG_6050marked.JPG
 
Yup. JB weld work good on those. Just a bit around them in case you ever have to take them out.
 
HALIFAXHOPS said:
Same here Bob looks like these but just the tops can be seen.

View attachment 1264687
Click to expand...
Ray,......thankx for the pix...
EXACTLY......these plugs have a slight taper on the body and a shoulder that locates the plug in the bore at the proper depth, then when seated, expands the shank slightly to seal the plug in the bore. They are made from a softer aluminum alloy than the carb's body casting to be able to expand slightly to seal. Just my opinion of course.
BOB RENTON
 
I have had them leak in the past. Bitch to find them leaking.
 
Stuff some paper towel in that location and refill bowl. See if they get wet and rest of body dry.
 
Will jbweld stick to aluminum there or is there some epoxy you recommend to seal them? I dont want to take them out. All the carb shops are from 8 weeks to 8 months backlogged and I am not a patient guy LOL and have already missed several shows I was hoping to attend.

You guys are awesome!
 
Yes if prepped right, but I would validate that is the issue first. And only issue. They are hard to come out, without proper tools, but it could be done. Best fix is to remove if they are the leak, and then reseal with new plug with sealant. I do not think any of the shops mess with those plug or cleanout ports. I have had to remove the front idle port plug to get at a broken mixture screw and ensure all the drill chips were removed. Best method is to drill, tap, and pull out with a small screw. The the rivet removing tool will damage the rivet and possible mar the body if your not careful.
 
Dragon Slayer said:
Yes if prepped right, but I would validate that is the issue first. And only issue. They are hard to come out, without proper tools, but it could be done. Best fix is to remove if they are the leak, and then reseal with new plug with sealant. I do not think any of the shops mess with those plug or cleanout ports. I have had to remove the front idle port plug to get at a broken mixture screw and ensure all the drill chips were removed. Best method is to drill, tap, and pull out with a small screw. The the rivet removing tool will damage the rivet and possible mar the body if your not careful.
Click to expand...

I am going to do a couple more tests today to make sure that is where the fuel is coming from. Thanks
 
Did a test and the fuel does not come from the primary passage plugs. It ends up on the scondary throttle plates and drips down from there. Not sure where it is coming from. Will try blocking primary and secondary jets separately to see which one is the source
 
fmahannah said:
Did a test and the fuel does not come from the primary passage plugs. It ends up on the scondary throttle plates and drips down from there. Not sure where it is coming from. Will try blocking primary and secondary jets separately to see which one is the source
Click to expand...

EXCELLENT methodology. By isolating the primary circuits from the secondary circuits, you should be able to find the source of the leak. Does the Carter 3705 carb have a auxiliary fuel feed circuit that is part of the secondary booster venturi assembly? If so, does the booster venturi fuel feed well (where the booster is attached to the body casting and accommodates the secondary venturi 's emulsion tube and air bleeds) have any drilled passages that MAY have developed a crack near the secondary throttle bores? If so, this could be the source of the secondary fuel leak.....just speculating........
BOB RENTON
 
Primary side can't spill fuel into the secondary. How high are you filling the bowl? If you fill it above the seam level of the secondary booster it could be leaking out between the gasket and the venturi and establishing a syphon. But if it is not leaking their it is and it is leaking out the shaft you might have a damaged base. You should be able to feel the secondary bore above the blade is it wet anywhere? If not I am afraid your source may be internal to the shaft bores. If it is leaking down the back of the secondary from the secondary venturi gasket, then may be something repairable. But the fact it leaks down to the level of the secondary jet is scary. That means the leak is low. If not the plugs for the fuel channel, it has to be a crack in the body along the shaft or secondary well.
 
If the venturi gaskets are not correct could that cause any issues? I noticed when putting it back together that the gaskets in the kit did not exactly match the ones that were on it when I took it apart. Does anyone have pics of correct venturi gaskets for a 3705? The kits I bought were 4051A from quadrajetparts.com.

Tomorrow I will make sure I am not filling above the secondary booster seam

Hope I don't have to order Mancini Eddy carbs, they said it can take 2-4 weeks

Thanks
 
I need to get this car driveable so I can take it to shows, and these carters seem to have issues, so I am willing to get a couple edelbrocks to put on it for now. Mancini will sell me everything in their cross ram manifold/carb kit minus the manifold, but it can take weeks for them to get the carbs. They say they calibrate or modify the 750s to work on the wedge intake, and I think it requires some special throttle linkage adaptors?

Edelbrock offers 500 cfms tuned for dual quad applications but I would imagine those are for inline setups and not crossrams, and I don't see any like those in the 650/750 cfm range. Mancini recommends the 750s not the 500s.

Has anyone used Eddys on a crossram, and if so which ones would you recommend and does it require a special linkage to hook them up on a factory crossram with factory lnkage? Note this would only be temporary until I can get the carters fixed.

THANKS!
 
If the gasket was not sealing it might. Usually, kits have several styles of venturi gasket to cover all models. Should have been a standard sec gasket, sized for the venturi. 5 round holes. 2 for screws, large center for fuel pickup and 2 additional on rear, one for Sec discharge port.
 
Dragon Slayer said:
If the gasket was not sealing it might. Usually, kits have several styles of venturi gasket to cover all models. Should have been a standard sec gasket, sized for the venturi. 5 round holes. 2 for screws, large center for fuel pickup and 2 additional on rear, one for Sec discharge port.
Click to expand...

I remember the old gasket having a slot connecting two holes but the new one not having the slot, but my memory is not the best LOL. Will see if I kept the old ones or not and compare.
 
fmahannah said:
I remember the old gasket having a slot connecting two holes but the new one not having the slot, but my memory is not the best LOL. Will see if I kept the old ones or not and compare.
Click to expand...

Here is what the original venturi gaskets looked like. Compare to the kit gaskets photo and you will see one gasket matches but the other one is missing the slot connecting two areas? Not sure how critical this might be for correct operation? I guess I could put the originals back in and see if it makes any difference in how rich it runs.

Thanks!

originalventurigaskets.png kitventurigaskets.png
 
Should be the lower far left gasket on your kit picture. No slot according to the Carter service manual for your carb.
 
Dragon Slayer said:
Should be the lower far left gasket on your kit picture. No slot according to the Carter service manual for your carb.
Click to expand...

So they had the wrong gaskets in it and the kit was correct?

Where can a guy buy the carter service manuals if any are available?

Thanks!
 
Dragon Slayer said:
Should be the lower far left gasket on your kit picture. No slot according to the Carter service manual for your carb.
Click to expand...

I suspect I might have the floats set wrong as well. Set for 5/16 float level, but I see some sites saying 7/16 is correct. And I think an 1/8 difference might be enough to cause some flooding? Do you know the correct float settings for 3705 from your manual? It is hard to find the right settings when everyone says something different so would rather get it from factory settings if possible

Thanks
 
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