possible fuel issue?

[ndutton]

Disconnect the black wire from the distributor to the coil "-" terminal when you need ignition system power and no engine run.

[Don Moyer]

Condensation

MN John, this is a bit of a long shot, but if you have pronounced condensation on the outside of the carburetor, it's likely that condensation is also forming on the inside of the carburetor. Some years ago we received a report that one of our engines was running rough and small amounts of water were getting into the oil and turning it milky. The customer mentioned in passing during one of our conversations that he saw lots of condensation on the outside of the carburetor. Long story made short, the engine happened to be a Stevedore with the restrictor ring inside the flange of the manifold which apparently acted as a venturi; creating high velocity, lowing pressure and temp, until warm being drawn in through the air intake cooled and condensed enough to cause it to "rain" in the induction stream. The restrictor ring was removed and the problem went away. Don

[MN John]

condensation

OK I will take a closer look at the possibility. I do have the scavenge tube spacer, so maybe some type of restriction and it also makes this passage longer allowing it to get colder than normal? I will think on it, maybe it could be insulated? IMO the condensation is pretty severe, beads up heavily like a glass of ice water and can get bad enough to start running down, I do not have milky oil. Thank you for your response, made my day to hear from "the man" himself

[Don Moyer]

Condensation

To be clear, we've only ever seen one case of condensation in over 25 years severe enough for visible moisture to make it through the combustion process (presumably through one or more cylinders that were misfiring from the moisture) and into the oil pan, and that one case was due to the Stevedore restriction in the manifold. If you remove the carburetor and feel for the restriction in the flange of the manifold (which is the only difference between a regular Atomic 4and a Stevedore model) and you find no restriction, then we're paving new ground. Don

[Dave Neptune]

Is the condensation there after running for an hour or when all warmed up?

Check for the restrictor that Don mentioned.

I assume you are using "regular" grade gas, not AV gas.

Dave Neptune

[MN John]

Yes, I understand that it is unlikely that this is my issue. I will get motor running and try to get some pics of condensation, then remove carb, and check for restrictor and take some more pics. I only have internet on my phone, so I will do the best I can getting back with more info/pics

[MN John]

Condensation does go away eventually when running, I will keep a closer watch for what is happening when I have symptom. Don't know what AV gas is. I go to a large chain station near marinas that has gasoline labeled 91 no ethanol added
I will get back with my findings and pics

[roadnsky]

John-
I'm with Neil that your coil is most likely toast. We need to eliminate it as an issue.

The 91 octane fuel is ok. Even better with no ethanol.
Next time you can go with a lower octane rating though.
What us old-timers call "Regular"...

[JOHN COOKSON]

Not Much; But Here It Is

There is a kind of loud sound coming from carb when running, like if u were blowing into a straw and very quickly covered and uncovered the end. I thought this was the sound of debris in a jet, but I now think it is the scavenge tube picking up a bit of fuel in throat? !

Betcha this noise and the condensation are related. Can't prove it. It's temping to say air leak but it doesn't feel right to say that.
Best I can offer for now is this: You mentioned the scavenge tube. Is it tight at both ends and not letting a bit of air in? One thing I do know for sure my scavenge tube doesn't make any noise.

TRUE GRIT

[MN John]

quick update

Couldn't get condensation and no symptoms. Engine compartment 85degrees, 41% humidity, much higher earlier today. Temp at carb nearly room temp at 81, intake at connection 56, just above near center manifold bolt 110's.
Now I will take carb off and check for restriction.

John C, I did break scavenge tube at one time and put new end on, could have done it wrong. I used quite a bit of permatex aviation gasket on all connections, maybe bad? Also have two gasket connections instead of one because of spacer so maybe a leak in one of those? Possibly able to suck condensation from outside if it is leaking? I will tighten up scavenge fittings.
Roadnsky, I totally agree with coil situation, just need to order and wait for it to arrive. I use the 91 because it is the only gas I can find labeled no ethanol and I think I remember reading in a old A-4 manual to use 91 or 92 and its 2.65/ gal down here by the lake and its about 3.50 in the city
I am going to remove carb now and check for restriction and take more pics

[MN John]

no restriction?

Doesn't look like any restriction? Was "wet" on gasket between intake and spacer, see pic. Smelt like gas but a little thicker almost like oil? Spacer to carb was good, until I ripped it( that's why I have spares right?) Little puddle of gas/ oil? In throat of carb. Lot of aviation gasket everywhere( swear it wasnt all me)Well that's where I'm at, back at it tomorrow. Time to do some reading

[JOHN COOKSON]

. I used quite a bit of permatex aviation gasket on all connections, maybe bad
pics

My philosophy is it is a good idea to use a light coating of goop on connections to augment or otherwise help a seal. Depending on the goop to make the seal means something is wrong and introduces a possible failure point.
I thought permatex aviation was for metal to metal seals not so much for paper gaskets. There has to be something that is better for paper gaskets - I just don't know what it is.
What some do is put the goop on one side of the gasket so it stays stuck and the whatever comes off cleanly from the uncoated side and the gasket can be reused.

TRUE GRIT

[roadnsky]

John-
Do you know WHY you're using that "spacer" between the carb and manifold?

Also, if it's the Indigo spacer for the PVC valve, then there are TWO fittings (holes) in it.
I can't tell in your pics if your's has two.
Can you look?
If there is, what is plugging that 2nd hole?

I'm wondering if that spacer is your issue and if it's even needed?

[MN John]

carb gaskets

Cleaning up and tightening scavenge tube and putting new gaskets on carb. Yes I do the goop on one side so it can be disassembled. I will use less aviation gasket and keep it a little cleaner.
I have a set of "black" gaskets and "green" gaskets. Any preference or either will do?

[MN John]

spacer

Roadnsky, from what I believe the late model carb on early block requires this for locating scavenge tube from bottom of carb. I do have the spacer with two holes but I am using one with only one hole. Pic should show scavenge tube from bottom of carb throat to spacer. I have it disconnected in pic