WJAJR wrote. A Quick story.
I have a slant six that was carboning up the plugs/ running rich at idle.
I adjusted idle mix ,put in new plugs leads , Checked timing etc.
Any way I decided the carb must be the culprit.(Carter BBS)
So I pulled the carb . straight away I could see the problem.

The Idle adjust screw hole was clogged with carbon/crap ,so when the screw was turned clockwise (ie leaner) it would stop about 3/4 of the way in .
It felt like the screw was bottoming out when you turned it in,but it was not.when the screw was turned all the way in the engine would stall as it should.There was no fine adjustment ,either stalled engine or ran rich.


So I cleaned out the idle screw hole and then the screw tip was able to be screwed the whole way to the seat.
Put carb back on and adjusted idle . Problem solved!!

May be something to look for.
Brendan.

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1963 AP5 Valiant 225 PB 904 Stock except extractors & 2 1/4 inch exhaust.


1962 S series valiant 225 PB auto. factory every thing. Full restoration job.
Currently on hold till AP5 is on the road.

Free fixes are the best! I just patched a crack in a $200 minivan radiator with some plastic epoxy I bought with a forgotten gift card, free fix! BTW that 2 part Chem-trol (?) epoxy is the best, comes in a box, not a tube. it was $11 per use but worth it. Dries smooth like volcanic glass and about as hard.

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I didn' t buy it, I built it.....

@WJAJR
Excuse me for taking so long to reply but to answer your question,it pretty much smells of carbon all the time but,some times it seems to be worse than others while every so often it seems non existent. But if I had to pick one or thee other I'd say "All the time".
PS:Thanks for the "Quick Story".

There may be other problems as well, but if the car's been sitting for any length of time, the valve stem seals should be suspect. Luckily, they're pretty easy to check. Just pop the valve cover and you'll see the rubber caps inside the valve springs. You might be able to poke them with a screwdriver to see if they're still soft.

Sometimes it's more obvious. FYI: My 225 was completely rebuilt in 2004, then it sat unused from 2008-2012. When I got it running again after a carburetor rebuild, it smoked like crazy. Pulled the valve cover, and the valve stem seals were practically GONE. Just hard bits of broken plastic.

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Somehow I ended up owning three 1964 slant six A-bodies. I race one of them.
Escape Velocity Racing

@SpaceFrank
Yeah I guess they'll do that when they sit awhile huh? But truth is my Sons car don't smoke oil,but it definitely has an extremely high carbon output(so much so that I can smell & taste it while we're riding down the road with all the windows rolled down) & if I was left to guess what was causing it,I'd say something's blocked & prohibiting/restricting the correct air fuel mixture(Hell IDK). But I do know this:
For as long as we've known the cars previous owner, he always drove it(everyday). But I can't speak as to whether he had it sitting for any length of time or not prior to us knowing him. Anyway the weekend's just about here, so my Son & I will pull the the valve cover off his Slant6 & have a look at the seals. I meant to do work on it last weekend but we were both too busy. I'll post the results ASAP. Thanks for the info & L8r Bro

Bad valve seals would cause blueish white puff of smoke at start up, and at other times under way. That puff of smoke does not smell like over rich mixture exhaust, just burnt motor oil smell. Oil combustion makes an oily black deposit on plugs not a dry carbon black deposit.

Where you say there is no smoke, I suspect an over rich condition from a poorly adjusted or dysfunctional carburetor rather than lack of valve stem oil control, or bad oil ring control.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

@Wjajr:
I agree 100%, a "Mal-Adjusted or Defective Carb" would manifest as a Rich-Burn. Besides I've never seen his car smoke oil(not during heavy acceleration nor at start-up). A while back I took my Sons Plugs out, cleaned em & put em back in & as soon as it started fouling(aprox 7days), I pulled em back out, took pix, cleaned & reinstalled em. They all looked fine, except plugs #1 & 6(6 is the only plug showing oil). Anyway I uploaded the pix to my SkyDrive in-case anyone might be willing to take a look at em.> https://skydrive.live.com/redir?resid=6 ... kxKdmZKyiM
PS: If the Carbs adjustments are "outta-wack" shouldn't we see carbon deposit on all plugs rather than just the two outer plugs(1 & 6) ?
Thanks for your insight Wjajr

This is not unusual to have numbers 1 and 6 plugs to show differently, there are differing theories on the subject, and Ill let it go at that.

Try running a hotter plugs in #1 & #6 and see fouling lessens. This wont fix the root of the problem, but it may lessen the symptom.

Any flooding, or excess fuel dribbling from carb after shut down depending on how level the ground is, will most often end up draining down through #6 leg of intake manifold to cylinder and into sump.

After car is fully warmed up, kill engine, remove air cleaner, and look for fuel dribbling into manifold. If there is "dribleage" or any wetness, check float level, float needle valve for good seal, sunk float, and or fuel boiling; four conditions one or more in combination that cause fuel dribbling.

Oh, if it's a Holley power valve equipped carburetor, the power valve diaphragm may be ripped, or too high of a vacuum rating both will cause constant over rich condition.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Make sure your ignition system is up to scratch,sure a bad fuel air mixture can cause plug fouling but a weak ignition can also cause you some similar issues. If your keeping the car upgrading to a HEI system is money well spent,even on an older engine. Failing doing that,at least make sure the coil,leads,etc etc are all good, then you have peace of mind and can rule out ignition. Does you engine have a heated manifold? Is the valve working? One and six could go rich if the manifold is cool and the fuel drops out of suspension? Just a thought!

Slant Steve: Fuel dropping out of suspension leads to lean condition, and raw fuel finding its way to rear cylinders and possibly the sump because of engine's rear being lower than front on level ground.

I have a Clifford intake & headers that I added a hydronic hot spot under carburetor to combat an icing condition. During a cold start up in cool weather, say below 45 degrees, my o2 sensor shows lean with choke still partly closed before full warm up reached. The colder out it is, the longer time she suffers from fuel dropping out of suspension.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Thank you both for your insight. Unfortunately,that which comes easily to some,is a foregin langauge to others & that'd be me. Fuel dropping out of suspension is a term I don't fully understand. I mean,clearly fuel is dropping(but from where?) down the carbs throat, into our intake? & if so, how do we fix it ?(put air shocks on the car & jack the ass-end up) LOL. I'll tell Ya,although I don't know much about em(other than they're really easy to mess up),I can see some carburetor work in my future(research atleast). So I need to figure out exactly which carburetor we have over here & find out what my next step is gunna be from there. Does \6 have a Write up/Stickie to help folks distinguish between the various stock carbs that come on my Sons 74 225 ? Or did it just come in one type(model)?

I hear yeah, when my forensic pathologist chief medical examiner MD brother starts yapping I sometimes get lost in the weeds too… Think nothing of it. I’ll try to explain.
Do we agree that a carburetor is nothing more than an air & fluid mixing device that takes a big glob of liquid from fuel bowl, and atomizes it into little tiny vapor like droplets that are dispersed into moving charge of air?

Now picture a very humid air mass such as fog, and a tall aluminum tumbler full of ice and tea cooled to 33 degrees f. What happens to the exterior of the aluminum tumbler, does it stay warm, does it cool down, or does it get very wet from condensation? Yup it sweats to beat the band making puddles on the table in just a few minutes.

Now if you warm up the aluminum tumbler with hot coffee, the exterior stays dry because it is above the dew point; a temperature high enough to prevent condensation from humid air.

The same thing happens inside of an intake cold manifold, atomized fuel condenses on the internal surfaces, and by chance if there sufficient humidity in the air on a cold day water can also condense in the same manifold causing puddleing of fuel and water on floor of manifold. Sometimes conditions can be such that water will freeze, or in other words cause icing.

Also there is the additional slight cooling of air fuel mixture when it passes from base of carburetor into the larger cross sectional area of intake manifold; Joule–Kelvin effect for one's reading plesure…

When fuel condenses on manifold surfaces some not all of the fuel will drop out of suspension causing the air fuel mixture to become leaner; in other words less fuel or more air. That raw fuel will run down into cylinder causing additional poor combustion conditions; some of the liquid fuel will find its way into the sump, some of it will be spit out the exhaust as partially burned hydrocarbons. All this adds up to poor fuel economy, and crappy drivability not to mention accelerated engine wear if not controlled.

The way to combat fuel suspension and icing problems is to heat up the intake manifold as quickly as possible. The factory did this by directing hot exhaust gasses to the underside of intake manifold below carburetor, and having an exhaust manifold arm adjacent to each intake arm. Additionally a system to direct warmed air to air cleaner during cold starts has been fitted since mid-sixties to lessen drivability issues. This design works very well in cool climates.


When headers are fitted, the carb & intake manifold can’t be quickly heated by exhaust flow as there is no mirage of the two to conduct heat transfer, only engine compartment air to transfer heat to intake. In a warm climate this is not much of a problem, but in Maine or other cool locations it is a big problem where we only have a few months a year with temperatures above 70 degrees.

After market manufactures at first made no provisions to heat the /6 intake manifold as headers and aftermarket intakes were probably thought as a race item only, but at some point they began providing a hydronicly heated intake by cutting it into the heater loop. Hot coolant works preventing icing, and provides faster warm up, but not as well or fast as the factory manifold heat method.

Hope this helps.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

It took awhile to post cause I had lots of reading to do. Reading that needed to be comprehended ! I read a number of threads & posts including wjajr's "Do we agree" post located within this thread. As well as the ones linked below, till I can finally say I understand what "Fuel Dropping Out Of Suspension" means. Thanks for the heads-up guys.
Wjajr's ice prone Clifford Intake @ Fuel/Heat Distribution Problem
http://slantsix.org/forum/viewtopic.php ... ot&start=0
Got a skip coming from the back three
http://www.slantsix.org/forum/viewtopic ... sc&start=0
Aggressive Ted Schultz’s 74 Dodge Dart Swinger
https://skydrive.live.com/?cid=32f1e50d ... A03C%21112
Intake Manifold Heat
http://www.rasoenterprises.com//index.p ... &Itemid=49

Anyhow we finally got to changing the Oil & installing the Fel-Pro Rubber Valve Cover Gasket, NGK's & Tube Seals about 2 weeks ago http://sdrv.ms/1bKKct2 & although I'd be the first to shout hurray! because the strong Carbon smell is gone & the NGK's made a huge difference with regards to Power & Idle. My Son's 74 Dart is still exhibiting a "Ruff Idle at Warm-Up" & (although lessened considerably) a sorta Stutter or Hesitation at acceleration(both while warm or cold, from a dead stop & while coasting). When I pulled the Valve Cover I got that same strong smell of Carbon & since we replaced the gasket it's gone so I'm good with that. However the following linked photos http://sdrv.ms/1dePxWd show my Son's (H1 1945/40 ?) is leaking fuel all over his intake(Boil-Over) which would account for raw gas fumes in the cabin. But I don't know much about carburetors at all, except that this model's most likely a complete P.O.S. & I'm gonna have to learn how to fix it. So if anyone would help us out with a sorta virtual inspection & diagnosis. We'd sure appreciate it,because my Sentras down rite now & with temperatures hitting 25* here in N.Cal my Sons old Dart is acting as our daily driver.

I'm gonna post the symptoms as accurately as I can, in hopes that it'll help someone diagnose the problem/s.
Anyway this morning @ 7:15AM, the temperature was 27*. I gave the gas pedal 1 tromp to engage choke mechanism & let off. Then I cranked it. Straight away(within 2 seconds) Vaarrrroooooom!!! it started rite up(as always), but as usual within 15 seconds it started running very ruff. So I depressed the gas pedal(just a lil) & it seemed to help(a lil). It was very cold outside(coldest winter we've had in N.Cal in almost 20 years). So anyway I tried to keep it at a manually induced "Fast Idle" for like 1 minute, but my boy was gunna be late for school, so I dropped it in drive & off we went. However 3 blocks down the road there's a stop sign, so I let up off the gas pedal & it held an idle(a lil ruff still). But as soon as I went to give it some gas(so as to turn onto the main blvd) it died. Oh it started rite back up within a second(as it always does), but it'll die again when I accelerate from the next stop sign, & it'll continue to do that until it's warmed-up(fortunately for us that's not too long). But it ain't rite & I can't have him driving it like that. He's only 17 & inexperienced on how to feather or baby a carb. I can just see him stuck at a green light trying to get it to start(folks'll start honkin & he'll panic). I'm not sure which Carb this is, but it does have a divorced choke & I think it's a 1945, yet it has of the Pump Rod Operating Lever of a 1940. Any help is greatly appreciated.
My Sons 74/6(H1) 225/904

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@ WJAJR.
I apologize for failing to answer the questions asked in your previous post(no disrespect intended). I guess I missed or forgot about em due to my feeling overwhelmed & frustrated. I'll get out there & check the various points you're referring to & post the results ASAP(rite after Christmas).
PS: Thank all of you for your help.

The engine only stinks until it's warmed up & as for the Choke Pull-Off, I applied vacuum & waited to see if the diaphragm held suction(it did), but the Choke butterfly doesn't appear to be fully opening once warm(or at-least that's how it looks to me). The engine does have an EGR, but it's not attached to any vacuum hoses & as for checking the "idle mixture screw adjustment & the carburetor bowl for "high fuel level"(I'll have to read-up on those, because I don't know those procedures).
PS: I don't think the linkage part of Pull-Off is working correctly, because when vacuum is applied I don't see the butterfly move at all ?