Carburetor Health Check...

Hey Gang,

I was peeking down in the carb today as it was running and I noticed that one of the primary jets (venturi?) appears to have fuel dribbling out, while the other one appears to have nothing coming out.

I’m hoping that the side that appears to have nothing coming out is actually flowing atomized fuel, which I couldn’t see.
I’m pretty sure that the dribbling fuel is not optimum, and probably indicates some gunk in a port.

I’m guessing a tear down and thorough cleaning would be in order?

Took a quick video…

Carb has also been a little “sticky” lately, hanging up intermittantly, keeping the idle up at about 1250rpm or so. A quick blip of the pedal and it drops back down to 750. So today I gave it a good spray with carb cleaner just before this video ~ haven’t tested it to see if it is still sticking.

Emulsion tube air jet is probably partially blocked. The air jet is that little tiny brass piece on either side of the venturi at the front.

I would say, thorough cleaning is definitely in order. Even a chemical soak for a day? Then a good rebuild. Could be a few different things.

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Thanks Fellahs!

I learned what an emulsion tube air jet is today, and where they are located! :slight_smile:

I remember squirting cleaner through them when I rebuilt the carb (2 years ago now), but I had no idea if they could be removed, or how to do it.

So, do those actually come out? I went through my carb pics ~ do you have to tap them out from underneath?

Hmm… looking at this pic, it looks like there is some damage on the nozzle / venturi on that side. Looks like it might have a chip missing from the end inside it, compared to the other side.

From what I have learned the intake manifold (original Ford) had certain uneven runner issues. They (Ford) would “modify” the original carbs to run better/even out these runners.
I have seen quite a few original carbs w/ the exact “differences”. This is to keep one cyl from running lean or rich as the case may be.

Hi Bill! Hope all is well with you! Thanks for chiming in.

The part I was talking about is the nozzle(?) inside the upper left venturi. It looks like it may be chipped, and I wonder if that could be causing fuel to collect on the rough edges and then drip down.
Either way, it doesn’t look right, but I don’t know if it is something that should be fixed immediately or if it is “normal”.

I bet that’s where the screwdriver was jammed in to hold the choke plate open during servicing :buck: Ahhh…the days of my youth.

FWIW, I don’t take the jets out I just spray them clean with carb cleaner and compressed air.

This weekend I fired it up and gave it some good blasts of carb cleaner through the emulsion tubes. It was definitely sucking air through the outside pair, as it would bog slightly as I covered them with the little carb cleaner tube and gave them a squirt. Seems that only the outside tubes were actually drawing air - is that normal? The inner emulsion tubes opennings are much smaller, and showed no signs of drawing air.

Either way, it didn’t seem to resolve my dripping fuel issue (drat!), so I’ll give it a few more tries with some “softening time” in there. If that doesn’t do the trick then it’ll have to come off for a thorough cleaning :-/

Get yer rebuild kit and a 6-pack and git’er done.

All those little passages+dirty Oregon gas+deteriorated gaskets= :sick: