1980 F150 2wheel drive I6 4 speed. 1 bbl carburetor .
The numbers off the tab on the carburetor read: eote aea a9 k4
Just trying to figure out what I have so I can find where the adjustment screws are, and what jets I will need ,where I can find them and where they are in this carburetor. Plus I need this information in case I have to rebuild it. which just sounds like fun to me.

 

Provided the carburetor hasn't been changed over the years, you've got a Carter YFA non-feedback carburetor. Not to be confused with the feedback models of the 84 to 86 era, or the older non-emissions Carter YF carburetor.

Fuel mixture screw is on the passenger side of the carburetor, down near the base.

Idle speed screws are on the drivers side, attached to the throttle lever. The one that rests against the carburetor is the curb idle screw, and the one that rests on the fast idle cam is the fast idle screw that raises the RPM's until the choke is fully open.

If you have the right size jets in the carburetor, you should be able to turn the mixture screw all the way in and snug it down LIGHTLY and kill the motor by starving it for fuel.

A ballpark adjustment for the fuel mixture is to screw in the mixture screw while the motor is fully warmed up (190 degrees) until it starts to shudder and shake like it's having a hard time running. Then, count the turns and back it out and richen it up until it smooths out. Keep going, then when the motor starts to shake from going too rich, remember the number of turns it was from too lean and divide by 2 to get the intermediate point of adjustment, then set the screw for that point.

As an example, let's say you'll have the mixture screw 1 1/4 turns out from fully seated as a ballpark default setting. You screw it in 1/4 turn and it's at 1 turn out from fully seated. This is as lean as it will go without wanting to die. Then, you take the mixture screw and turn it 4 full turns out until it's too rich. This is 5 turns from fully seated. 4 / 2 = 2. So, you'll want to screw it back in 2 full turns for a total of 3 turns out from fully seated and this would be your initial adjustment. This would put it right in between too rich and too lean.

That's as an example, actual number of turns can vary. The best way to adjust fuel mixture is with a vacuum gauge.

There's only 1 jet if I remember right, and you can get the right rebuild kits from parts stores if you have the appropriate info off of the carburetor. You'll rebuild it and clean it out, put in the right jet, adjust the metering rod and float, and you'd be good to go.

 

I agree. You can dial it in really well with a vacuum gauge.

Dial it in to get the most vacuum, then turn it in toward lean aproximately 1/8-1/4 turn should get you very accurate results.

My 1981 with a feedback carb, you have to do this several times, as the feedback solenoid will fight with you. Just shut the engine off for 30 seconds, and do the adjustments again several times until you get the same results in two concecutive times of adjustment.

That will get you as close as you can get without an emission tailpipe sniffer.

 

Thanks guys my cousin came and rebuilt my carb, no one could find the screw until we got it out of the truck with all the vacuum hoses and grime. We hope to dial it in more later this week but she is already running better. Now we are looking at the throttle return spring is trashed . can I just get the spring ( haven't really looked) or do I need to get a whole new throttle cable?