YFA Carb w/o electric feedback

Hey all, I couldn't seem to get my YFA auto choke to work properly(300ci). Thinking it was the carb I got a reman and slapped it in. Same issue. The auto choke won't move the choke once the engine has warmed up. I do know I need to install a fan shroud, and I even made a heat shield to block cold air from cooling the hard line. I even moved the line closer to the exhaust manifold to get it to heat up more. Now the other thing is the vacuum lines. The EGR system is no longer in play. In fact almost all vacuum lines are not in play. (Got the truck like this). I have a line to the HEI style distributor, and the brake booster. I need help getting the carb running correctly. Anyone have advice on where to start?

How about a picture or pictures of what you do have to give the rest of us see what is there and not there.

On the choke, with the engine stone cold, did you loosen the three screws that hold the black cap in place then hit the throttle all the way to the floor, then take an 1/8 drill bit between the throat and the choke butterfly and turn the black cap until the drill bit will slide between them?

I did not use the drill bit, I only made sure the choke butterfly would close and adjusted the spring to be just touching the arm. As far as pictures, I'll hit that up tomorrow. I do know that this is a hodge podge of parts. I will eventually have my spare block purpose built without all of the stock vacuum/electrical system. Right now I'm just trying to get this set up working as best it can so I can drive it up to NY here in a few months.

To further explain, the AC system is gutted. No smog pump and the EGR valve is plugged (I just found that out). The wires for the electrical feedback are all melted so I assume this isn't the correct carb for this truck. The distributor wasn't getting the command to advance the timing so I installed an HEI style distributor. Again just trying to get this carb working as best it can until I save the money to build the engine the way I want.

Ok so we are dealing with a 300 six motor and from the sounds of it you have done away with the feed back system with the HEI dist, and non-feed back YFA carb so we can get this thing to run good for you.

It also sounds like the choke may not be opening for you when the motor heats up, am I right?
If so yes a picture or more would be nice but lets see if I cant help a little.

As said try and adjust the choke so a 1/8" drill bit will fit between the butterfly and carb body.
You do have the choke fresh air tube & hot air tube going to the carb?
The fresh air comes from a nipple near the top of the carb opening.
Copper tube with the rubber hose is the fresh air nipple.

It then goes down to the bottom of the exh. manifold then out the top.
Coat hanger is in the bottom & top where the tubes should be.


The hot air side comes out the top and should have an insulating sleve on it going to the carb choke housing.

If your steel tubes are rusted Dorman makes a kit to fix this less the copper tubing.

Now also know the choke also has an electric hook up from the ALT "S" lug. You can see this wire in the first picture of the fresh air tube hook up.
This supplies about 6 volts and you need BOTH the hot air & this electric for the choke to work right.
Dave ----

I should point out that I am running EFI exh. manifolds and they do not have a way to run a hot air choke setup so I took the copper tubing and wrapped it around a manifold for heat.

It works pretty good so far I just need to adjust the fast idle speed up just a bit.
Dave ----

Thanks Dave, thats why I was asking for pictures to see what he had and dident have. You covered it pretty well.

He is in good hands now with you on the case.

I had 90% typed up last night and got side tracked
Pictures do help a lot
Dave ----

Where does that one wire hook up? Also, I may have to go the same route as far as the heat tube. Now what about all the vacuum ports? Will the carb work properly if I just cap them off?🤷🏼‍♂️
I’ll hit the adjustment this weekend. I’m glad you guys know what the hell your doing.

Also, I don’t see any place to plug in a wire on this reman carb...please advise😂🤣

pugster wrote

Also, I don’t see any place to plug in a wire on this reman carb...please advise😂🤣

On the choke housing the black cap there is not a spade to plug a wire on to?
Got any pictures of this carb?

As for the vacuum ports only 1 maybe 2 are used.
1 should be ported, no vacuum at idle but has vacuum when you move the throttle, this goes to the dist. vacuum advance can.
The rest on the carb can be capped for the most part.

On the intake:
Hose going to power brake booster.
Hose for the PCV
Hose for HVAC controls
Hose to the factory air filter to temp switches on the lid or side of housing to work the flapper in the air filter snorkel

That is about all I can think of off the top of my head.
Again pictures work help on this also.
Dave ----

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The only thing I have to run off vacuum is brake booster and distributor.

Can you back out some and get a picture of the choke cap?

All of those un used vacume ports need to be capped off untill you get to the point that you may need to use one as the vacume leaks will make it run really bad.  

@pugster I have about the same situation. I ended up adding an electric choke kit from Mike's Carburetors.

Works great so far.

https://www.carburetor-parts.com/Electric-Choke-Conversion--CU1112_p_4421.html

I appreciate the link. I just used some copper tube and it still didn’t work. So I may just run rich until I can order this.

No spades on the choke housing. It’s completely run off heat. What size copper tubing is that?