I recently replaced my Carter YFA (non feedback) carb with another rebuilt one because the first one's mixture screw broke off in the throttle body and couldn't adjust the mixture as needed. I have installed a manual choke on this replacement using the Doorman HELP kit. I have some questions about setting up the replacement which I have installed and have running.

Can I use the fast idle cam with a manual choke? How do I set it up? The fast idle screw with the manual choke installed doesn't seem to engage the cam very tightly like it does with the hot air/elctric unit.

Even with the idle mixture screw turned all the way in the vacuum barely drops below 20 and the truck still runs. Whats up with this? Wrong jet size? The carb is supposed to be for an 81. It's an Autoline c6246.

Thanks guys

 

The fast idle cam, choke pull-off and all that stuff should not be affected by the manual conversion. All the conversion does is change out the black piece so the lever is actuated manually. I have found out you need to install the manual choke kit exactly like the instructions. The kit I had used a somewhat complex actuating system on the choke lever, a bracket with a brass dog that fit on the cable. This setup let you "persuade" the choke to on, but it gave it some play when you moved the the cable to let the choke move freely a certain amount. It's hard to explain, but it worked well when it was installed correctly.

On your idle screw, the most common problem that causes the screw to have no affect is the idle speed. If it's too high, you screw will not have much if any affect on the idle quality.

 

You should be able to use the fast idle. It has been a bit since I have done this swap but all you are doing IIRC is removing the old black cover and install the new guts & cover. Run the cable and hook it up to the new shaft and it should work.
Without looking at it in person, maybe post a few pictures, to say what is going on.

Ok first what is the idle speed set to? If the idle RPMis too high then the mixture screw will not do any thing as it will be on the high speed part of the carbs system.



Jet(s) only meter the high speed side of the carb as I said above.


If the idle speed is set to the factory setting and the mix screw does not do anything I would start looking for vacuum leak(s).
Hope that helps
Dave ----

 

I see this kit they sell now doesn't have what I am talking about.

https://www.amazon.com/Dorman-HELP-5.../dp/B000CO7CK0

 

I had to move some incorrectly connected vacuum hoses and then the idle mixture screw started working like it should. I didn't have the ported vacuum switch connected and the vacuum advance for the distributor was in the wrong port. Now I get 20 in of vacuum at idle.