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Discussion Starter #1
I am having a problem with the rear carb with excess fuel running into the bores. I originally thought it was a problem with the float, but that looks really good with no leaks. I submerged it for several minutes in water, about 20, when I released it, it came right back up to the surface, and no water was inside when I shook it.

Next I checked for pump discharge leakage. There was a small gasket between the venturi cluster and difuser, (synchromesh), but no gasket between that and the screw head. So I placed a gasket there.

That only leaves the needle and seat.

This had been a problem up until 3 years ago when I pulled the entire intake set-up off and ran the Carter AFB. 2 years ago I rebuilt the carbs and checked everything out with a fine tooth comb. So it has been sitting on the bench for the last couple years until a month ago when I decided it was time to reinstall it. When I put fuel to the carb it looked like a faucet running.

Even though the needle and seat and gaskets were new. Is this just from sitting and need a new needle and seat, or is there a bigger underlying problem that I am not picking up on? Thank you for any help.
 

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I have been running tripowers since the '70's, and have had good results using the old all brass needles without the rubber tip. I think the new alcohol-tainted fuels can hurt the rubber tip and the accelerator pump cup. My buddy has replaced two cups in his tripower car in the past 6 months.....I haven't worked on my '65 tripower's carbs in about 30 years, but they have brass needles and leather cup seals. I think you have a needle/seat problem, or the float is physically bent and hanging open against the side of the bowl, etc, keeping the needle/seat open. These are simple carbs, and, once set with original quality parts, are really bulletproof. Don't overthink it. Check the float, and needle/seat. Good luck.
 

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Discussion Starter #3
Thanks Geeteeohguy, I placed the airhorn back on the body, and turned the carb back and forth. I can here the float moving freely opening and closing the needle. I have been researching the needle and seats, and see a new style from Daytona Carburetor. Have you heard anything about these and how they might work?
 

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What are you running for a fuel pump? The original A/C Delco fuel pump was calibrated to supply only 4-5 psi. Aftermarket pumps routinely supply in excess of 7 psi, which is enough to unseat the needle from the seat in some carbs. It could affect one carb and not another in your tri-power set up.
 

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Discussion Starter #8
After looking closely at the rubber needle tip, there is one little spot that just doesn't look right. It does not look like enough to be a problem with the naked eye, but I just ordered a new needle and seat assembly from Daytona Parts. Hopefully this will fix the problem.
 

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Make sure the throttle plates on both end carbs are closing completely - 100% - if even a little air is leaking past them at idle, you'll have problems. GM had a special epoxy sealer they sometimes applied to the plates to make sure they sealed shut at idle.

Bear
 

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Discussion Starter #10
Thanks Bear. When I had the Carbs up on the bench I did a lot of work to ensure they were closed completely. The Daytona valves came today, hopefully by Sunday I will have time to work on them again.
 

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Discussion Starter #11
Got the car running today, Daytona Float Valve assembly, ther version of the needle and seat seems to be working fine, solved the fuel problem. Took the car out for test drive. It feels like the car is running on 4 cylinders and I have arcing from the negative side of the coil to the coil wire. Did the coil crack on me? Going to try to post the video.
 

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Looks like a cracked tower to me.....BTDT...You could try a better/tighter boot or a different coil wire, but my money is on a cracked tower. Time for a new coil.
 

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Looks like a cracked tower to me.....BTDT...You could try a better/tighter boot or a different coil wire, but my money is on a cracked tower. Time for a new coil.
That's what it looks like to me too, unless that white squiggly line in the photo is some sort of camera artifact and not really present.

Bear
 

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I believe the OP captured a spark jump in his still photo (probably a still capture of his video he tried to post).
 

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Discussion Starter #18
You got it Chuckha, I was able to pause the video and snap a screen shot of the arc. That picture does look kinda paranormal though..lol
 
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