My '79 has the 1-barrel Carter YF carburator. I took it off the motor to mount a new automatic choke tstat and while I had it off I sprayed it down with carburator cleaner. When I put it back in and tried to start the motor, I had raw fuel pouring out of carburator. Thinking the float wasn't working, I got a rebuild kit and replaced the entire float and needle assembly. I also replaced the accelerator pump check ball and weight. I checked the float drop adjustment and it was right on the money.

I put the carburator back together and installed it on the motor and it behaved exactly the same way. As soon as you crank the engine and the fuel pump starts pumping, you get fuel running out of everywhere on the carb. Actuallly I'm thankful nothing caught fire.

Is this a known issue? Maybe something simple.

 

the fuel filter threads are probably stripped. try getting a new fuel filter, and ever so carefully put it in, tight, but not stupid tight.do not use Teflon tape, it will disintegrate, and get into your fuel system. use Teflon in the can

 

The fuel filter is in the fuel line before the carburator. Fuel is leaking out of the carburetor itself. I'm still thinking it has to be float related. I'm gonna take it all apart again. Thank goodness it's not that hard of a vehicle to work on.

 

Likely the needle/seat assembly. New ones are prone to not sealing real well at first. Try using a screwdriver handle to tap on the top of the carb, and see if that will stop it from flooding. I bet the original issue was the same basic thing, except it had some trash that got into the needle/seat, from jostling the carb around.

 

There is a lever arm on the side of the carb that attaches to a vent for the carb. I rebuilt mine recently and had the same problem. Make sure you replace the seal that is on the inside(rubber seat). I got lucky and the arm pivot just had to be tweaked a little bit.

 

Hiyas!
I recently rebuilt my 1980 Carter - it was flooding the engine with fuel and the plugs were blackened in mere miles.
Got a full kit, checked the float for - well - floating in a cup of fuel - it bobbed like a piece of styrofoam in the lake. Triple checked all my measurements and put it back on. Fired right up and after a few turns of the screwdriver, idled and drove like a champ. But STILL drinking fuel like a demon? Took it apart again and re-checked all components, re-floated the float, etc. - put it back on and STILL under 14 MPG's from a 300, manual 3-speed, 2.75 gears and 4 times oversized (diameter) tires (makes the gears more like 2.50 or even lower) - and sticking to around 55 MPH actual. (1700 RPM's, or 48 MPH on the speedo) Even had the choke unhooked. (full open) Exhaust butterfly seems to be opening correctly. Plugs look like new now.
Anyone have any idea of what I may have done/missed in this carb? I re-checked the metering rod, even backed the screw out an extra turn to drop it down a bit further on the 2nd time around. Filter is newer, fuel bowl was clean. No AC, No air-pump, tires @ 35 psi. Drove it like my Father would have.

OH! - After a few days, the carb and the fuel filter are dry as a bone - has to crank a bit to get gas to the carb - this is NOT normal - any ideas there? Thanks!

 

This can sometimes be a symptom of a dying fuel pump. The diaphragm that pumps the fuel can become porous and fuel will drain back through it over time.
A weak fuel pump may be causing some of your other issues too.

 

Just fired it up and let it run for a minute. Now watching the gas in the filter drain out towards the carb. Has to be going there, 'cause it's tilted down towards that end. Some way it can drain into the intake or something? like a siphon? (filter is lower than most of carb) I need this animal to do well FRIDAY. Or pay through the nose for 550 miles..

 

OK - just pulled the air breather and climbed on top of her. Looking down into the carb I can see fuel dripping from the main nozzle in the center of the venturi. I know THIS ain't to Hoyle..?

 

Annnnnd.. Just now pulled the carb off - again. Everything to spec, so lowered float height by 6/32" to see if that'll make any difference. Watching the filter and venturi now...

 

I rebuilt the carb and when the engine starts, fuel pours out of the fuel bowl vent, a stream as big as a pencil, which just drowns the engine. I checked everything. I bench-checked the float with compressed air, I readjusted the main jet needle to specs, but every time I would put it back together, it would do the same thing.

I gave up and bought a remanufactured carburetor from NAPA and installed it ($400). It does the same exact thing. As soon as the motor fires, a gigantic stream of fuel pours out of the fuel bowl vent that drowns the motor.

I'm completely confused now. There's not a whole lot going on there, it's a line from the fuel pump and the throttle cable. I get the feeling I'm missing something really obvious here, but I don't know what it could be. I have all the vacuum lines tied in below the carb at the intake manifold, so they haven't moved since before it was working.

 

Is your fuel pump stock? It sounds like your fuel PSI is through the roof.

 

Maybe, but it's the same fuel pump that's been on the truck since 1992, the mechanical one driven off the camshaft.

 

If you replaced the carb and it's doing the same thing, it doesn't sound like a carb issue, but a fuel issue. It sounds like so much fuel is pumping into the carb that it's blowing the needle and seat open, filling up the fuel bowls and dumping out the top.

I don't know how a mechanical one would go bad and increase in PSI, but that's all I can think of.

 

I believe it is simply a needle/seat issue. It sounds almost impossible for the issue to repeat with a reman carb, but it can. New needle/seat assemblies are prone to not sealing off well at first. It's like they have to "wear into" each other first.

Try using a screwdriver handle to tap on the carb just above the fuel inlet, and see if that will stop the fuel from pouring out the bowl vent.