Running rich....To big of a carb or?

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Your floats could be to high like a few of the guys said.
I would make sure the choke is opening up all the way when hot.
I ran a electric choke carb before and it would make the plugs very dark.

I just went to summits page and looked at the carb you have.
If it came with that set up it shouldn't be that far off.
That carb has really big jets from the factory...the fuel curve must be really lean to use that big of a jet.
That's a strange set up.
If that carb can be sent back i would send it.
If your not driving the car in the winter you don't need a choked carb.

I would get a proform 650 or 750 race carb.
I like them....my plus are really clean on my 318 and i use a 750 race.
I took the jets down 2 sizes front and back and it's great

look at the stock jets on a 750 vacuum secondary proform




67208_specs.jpg


And heres the jets on the race version

67200_specs.jpg



I run 72/82 jets most of the time and changed nothing else for the 318.
GOOD LUCK...........
 
I'm not cen sure where to start.... So many contradicting opinions, one guys says change jets, the other says don't, change power valve and other says power valve isn't the issue.

I know everyone is trying to help and thanks for the input, but I'm looking for some info that most everyone seems to agree on before I go spending money or time on anything.

As for the floats. Summit racing recommends the fuel level be exactly in the middle of each sight glass, not at the bottom of it. When I first got the carb it ran rich and the fuel level was atthe bottom of the sight plug even. So I raised it to the middle per recommendation while tuning it in some last year and it made no difference in how rich it ran.

As I mentioned before I believe my timing to be good.... But I still went ahead for trial and error purpose and tried setting my timing in multiple spots and then retuning the carb and still no change in the issue.

I'm going to snatch a vacuum gauge first of all and see how much vacuum I'm running and see what it tells me .

Otherwise at this point I'm not sure where I should be starting based off of all the mixed info, new carb?, jets?, power valve?, idle jets?....etc...etc...

It's seems like a lot of opinions are being based off of your run of the mill holley carbs. And not specific to the summit carbs (not sure if anyone even clicked the link on page one and seen what it even looks like). Anyone by chance here have any actual hands on time with one of these summit carbs?
 
I searched your carb and even looked at the pdfs. Didnt find a lot of info.I wanted a part breakdown diagram. Do you have the tuning book or video that is on the summit ad?If youre gonna tune it you should start with the power valve.It has to be correct so it doesnt dump unneeded extra fuel.Then you will be able to jet it correctly.
 
Also when you tune if you arent a pro an extra set of plugs come in handy.When trying a jet package swap in a couple new plugs and run it a week or so. Then you can read those plugs and get a good idea whats happening inside the cylinder.
 
You really need a vacuum gauge to determine what your vacuum is at idle, in gear. That is a good starting point. The 600 cfm comes with a primary 6.5 power valve, which was perfect for my 318 because I only hold around 13-14 on vacuum at idle.

The 750 comes with a 9.5 primary power valve. You will need a minimum of 19 inches of vacuum.
 
You can put power valve plugs in and it won't help is my guess.

If the spec sheet is correct, the IFR's are WAY too large.
 
cudavert said:
DOES it shut down with the idle mixture screws turned all the way in?
Click to expand...

xMOPARx said:
Yes I can turn the idle mixture screws in and cough the engine out.

However, while running at and idle around 750-800 rpm. If I turn the mixture screw in until it stumbles, and then back the screw out a quarter turn and repeat the same step on the opposite mixture screw. It runs good.... But I checked the position of the screws and at this point both screws are a half turn away from being fully seated. Not sure if that's right or not. But if I back them out any further than a half turn than i believe it will richen the mixture even more. And I'm aiming to lean it out.... Not richen it up
Click to expand...

Well, I would say that if you can turn the idle mixture screws in....like you said.....and make the engine die, then I don't see why you can't make it lean enough at idle. You can lean it out to the point that it's stalling! I think it may be that your cam is just lopey and inefficient at idle, and maybe that's where the burning eyes/"rich" smell is throwing you off.

xMOPARx said:
It runs good.... But I checked the position of the screws and at this point both screws are a half turn away from being fully seated. Not sure if that's right or not. But if I back them out any further than a half turn than i believe it will richen the mixture even more. And I'm aiming to lean it out.... Not richen it up
Click to expand...

Wherever the screws are positioned to make it run good.....is good! I wouldn't be concerned if they're only 1/2 turn out from being seated. If it works, it works.....
 
Do you know anyone that would let you try another carb ? If so just swap carbs for an hour or two..... Set timing back to around 15ish.... Drive car... If it runs better you know it is a carb issue...

Doesnt matter what brand of carb... Just make sure it runs good on the current car.
 
Ok I cant even read through this entire thread. You keep talking about a a smaller carb but that wont fix your rich condition. A bigger carburetor has higher airflow capability and thats it. I could put a 1250 cfm on my stock slant and not run rich IF i go through and tune the carb.
 
attach your vacuum guage to manifold vacuum and tune the idle mixture screws to the highest setting you can get on the guage and still idle well... then see how it runs....
 
Ended up being that the pump was pushing to much pressure and an issue with heat soak. Put a regulator on it to dial the pressure down and soldered and drilled an orifice and installed it inline on the return line to help equalize pressure and bleed off pressure with engine off. Problem solved.

BUT I sold the Duster soon after fixing said issue....about a year ago now.
 
You went to alotta trouble. All you had to do was install the regulator in the return and use it for the orifice.
 
RustyRatRod said:
You went to alotta trouble. All you had to do was install the regulator in the return and use it for the orifice.
Click to expand...

There was no return setup on the carb from the get go. And rather than buying new AN fittings to adapt to the dual feed line...etc...etc... I installed a 3 port regulator between pump and carb feed (line from pump to reg,regulated flow from regulator to carb and a line from regulator to return). was the cheapest and easiest route to take given the setup that was on the duster at that time. I get what your saying ...and yes it would have worked that way also...BUT I would have still had to buy fuel line, I would have still had to buy a regulator and I would have ALSO had to buy AN fittings to adapt it .

And it wasn't much extra trouble, I simply took an old brass jet I had laying around,soldered it closed, drilled it to the size orifice that I wanted. thread tapped a brass fitting that connected to the regulator and threaded the orifice into it and connected the line.

I bought 35ft of aluminum fuel line,adjustable holley regulator ..both on sale for I think it was $35.00 including shipping.

I measured,cut,flared and connected all the lines,mounted and installed the regulator,made and installed the orifice. And had everything up and running in a little over an hours time.

But again, it is neither here nor there now since like I mentioned before....the car is long gone.
 
My car has a 340 .030 508 Mopar Cam 750 Eddy Carb, 3500 stall, Holley Blue Electric fuel pump with 6.5 # psi ,shift kit and with this combo my car also runs a little on the rich side, so rich that running a 20% mixture of Cam2 you can hardly smell it but the car runs really really strong with no performance issues so I guess it will just have to run a little rich and have the top notch performance.
 
This is a 2-year-old thread but... IMO your performance will be good but depending on how rich it is you will wear out your cylinder bores much faster from fuel washing down the oil. You aren't losing anything (OK maybe a bit of cash) by experimenting with smaller jets and tuning the idle mixture and timing just right with a vacuum gauge. However you will make your engine last longer and get better gas mileage (not that you probably care much but hey it's less stops to the station!).
 
Post retracted....You sold it......Maaaannnnnn
 
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