1964 AFB 4V troubleshooting ideas?

[Fummins]

Hey Guys, noticed some light colored smoke white/blue coming out of my exhaust the other day after romping on the car, not hard but into the secondaries. Pulled a few plugs and they looked great, medium brown with no deposits or obviousnissues. Looking for some baseline settings to start on the carb with. Car is a '64 440 with 383/4spd and what I believe to be original/stock AFB, im sure its been rebuilt before, but not on my watch. Thanks

 

[rscurtis]

That's not a carburetor problem, IMO. Perhaps you were burning some carbon that was in the exhaust or the manifold heat passage.

 

[Fummins]

Hmmmm, i dont know about that....the smoke was constant this morning while car was idling while choked. It cleaned up at idle after warming up, but I could replicate it by revving the throttle quick and hard. I checked the mixture screws at the front base of the carb and one was damn near closed. I experimented with different setting and settled with each screw set at 3/4 turn out. It still smokes a bit under hard acceleration, im thinking a leaky shaft in the carb

 

[miller]

Leaky throttle shaft could lean the mixture some, even if set right.

Got a tach? You could get your mixture within reason, using a tach, simply adjust one mixture screw for high RPM, at idle. Needs to be at idle speed, or it will be off. Should find a short high RPM range...go for the high side. That helps the start.
Then match the other mixture screw setting to the one you adjusted.

That smoke could be from ring blowby, or just the mixture being off.

 

[dvw]

That smoke isn't from the carb unless you still have the choke connected and it isn't opening. I've run AFB's as rich as 10-1 fuel/air with no smoke. The old DC manuals have jetting options that may help. I've found most AFB/Eddy carbs to be very close in jetting out of the box. My blown 340 runs stock jetting with AFB's.
Doug

 

[Fummins]

I dont have a tach...hope its not rings. Would a compression check/bleed down test eliminate the ring theory? The choke is connected and appears to be working...although it looks like it may not be opening all the way...i could disconnect the choke to eliminate that as well, just disconnect the choke rod? I assume disconnect at the carb instead of the manifold (stock) right? Thanks

 

[Fummins]

Bad PCV valve?

 

[62 Dart Convertible]

Why would a worn throttle shaft cause smoke? Anyway, I was told by a guy who has rebuilt 100's of AFBs that he has never seen one that needed rebushing.

PCV valve? Does it rattle when shook? If so, it's OK. If not, replace it, cheap.

Disconnect choke rod and use wire to hold choke flap fully open.

Leakdown/compression test will tell you something of engine condition.

Sounds like oil to me.. I'd suspect valve stem seals as (if I read correctly) it smokes after you got on it (and when vacuum is high).
Need to pull rocker covers and look for broken umbrella seals on valve stems..

Either that or it's rings...

Also, I heard once about somebody that had a similar issue that turned out to be brake fluid sucked in to the intake from a brake booster with a leaky master cylinder...