I have a 1980 F100, 6 cylinder single barrel Carter carburetor. I bought a YFA replacement and everything switched over except this one lever that's in the front. Is there a way to add this or is it even needed? I noticed the new one has an additional lever on the right side that the old one does not, I'm wondering if this replaces the one up front?




The opening is there but is plugged and no shaft coming out for the split lever.

The gold diaphragm is the extra item not on the original carburetor.

 

I believe that lever is for the float bowl vent.
That nipple to the right is the bowl vent.
Old carb when the throttle got to a certain spot it opened the vent to the carb or it closed it but that is what it is for.
The new carb bowl vent is vented a different way through a relay.
Just hook the bowl vent hose up like it was.

That other gold part you asked about looks to be a choke pull off.
Dont worry about it as it should not have any effect on how the carb works.

That new carb also looks like it could be a feed back carb because of the gold plate held on with 2 screws in the bottom left of the last picture.
A solenoid would bolt there to adjust the carbs fuel ratio settings. Again dont worry about it.
Dave ----

 

Thanks Dave, I checked after I got your reply and you can hear it opening in the bowl. With that cleared up and everything else is switched over time to install it. The only other variation I found was a thin tube coming off the exhaust and going to the carburetor. The original mount was on the drivers side, new carb has it on the passenger side, opposite of the choke pull off as you called it. Just as well, the tube was rusted off so I'll dig out the tube bender and make a new one.

 

I have seen some with the hot air on the right side like your new carb.
My carb, 81 F100, it is on the left side like your old carb.

Just note besides the hot air tube coming from the exh manifold to the choke there is another tube.
It goes from the top of the carb by the air filter flange (nipple) to the bottom of the exh manifold.
The tube is the fresh (filtered) air tube for the choke.

I have some picture of the tubes and hook up to my carb on my site if you need to see them.
Dave ----

 

Yes, if you could send me that would be helpful. I have a vacuum line that was plugged with a bolt and not sure where it goes. Here's what it looks like, it's the thick one in the middle, just below the rim.

 

Yes that is the one. Should go to the bottom side of exhaust manifold to a metal tube like up top.
I will post pictures when on my pc.
Dave ----

 

Here is the exh manifold showing where the metal tubes would be top & bottom.

Here is where the clean cool fresh air comes from for the hot air choke. This tube goes down to the bottom of the manifold.

It picks up heat and comes out the top and goes up to the choke. Here you can see it is on the same side as your old carb, has the white covering on it.

My choke also uses electric from the ALT "S" stud and between the hot air and electric it works pretty good.
FYI Dorman make a repair kit if you are missing the metal tubes and no way to hook them to the exh manifold.

You dont get the copper tubing in the kit. The metal half cup gets put on the exh manifold and the metal line goes in 1 end and the other up to the carb.
I dont know how well it works as I have never used the kit.

Now I do have to say my set up is a little different because I am running EFI exh manifolds and they dont have a "pass thru" for the hot air part.
As you see I used copper tubing and put a few wraps around 1 of the manifolds to pick up the heat. Everything else runs just like the factory had it.

Now once I got the truck on the road and the weather got cold I found the choke would not open. It did not get enough heat from the wrapped tubing.
I had to get header warp and cover the copper tubing where it wrapped around the manifold and it now works as it should.
Dave ----

 

Excellent info Dave, thank you so much. This will be a big help. Since I bought this truck it never liked cold starts and idling. I'm hoping the new carburetor and ALL the vacuum and heat tubing connected properly will run like a champ again!

 

It may need a little tweaking once all hooked up and running.
My choke needed tweaking. It worked good when warm / hot out but when the temp dropped into the 20's it would not open and stayed on fast idle.
That is when I added the header wrap to get more heat in the tube and a little cap adjusting and has been good since.
Dave ----

 

Well after a couple of difficult weeks dealing with covid I finally was able to get back to the F100. I installed the new carburetor and added the risers thanks to Dave's pics and guidance. Truck runs like a champ now! It actually idles smoothly and starts right up even after sitting for a few days. Funny thing, there was always a loud clatter during the first 15 minutes or so of driving it. That is completely gone now. I thought there was something loose under the dash rattling as I drove. Now I don't know what that was as it drives so smooth the rattle is gone.

 

Is that an ebay carb??

I've been contemplating getting one for my 1981.

There seem to be several different vendors offering the same carb.

Would you mind sharing a link to the one you bought please?

It sounds like you got a good running one!

Thanks
Randy

 

Covid kicked my butt and is still giving my wife a hard time and that was like 3 weeks ago.

Good to hear I was able to help and the truck is running good 👍
Dave ----

 

Here is the one I bought on ebay: https://www.ebay.com/itm/323438266583

 

Thanks, that ones sold out but there are others that look basically the same.

 

I also found several variations. I tried to pick the one that was the closest match to my carburetor.