So uh... I might be a little brain damaged. After 3 days of being the guy in the truck turning the key I got out and let him do it, and the first thing I noticed is the choke is stuck in the wide open position. "Has it been like that the whole time? Yes."

So I fiddle with the choke, and it starts. It took a bit to get it running smooth but it was absolutely the choke not working right. I took it apart and figure out it was in backwards, so that was embarrassing.
No tach, but another buddy has a timing gun so we're going to be thorough and careful now going forward.
It runs smoothly now at idle and even in gear it idles pretty well, we're not 100% there yet but we're damned close. We took it for a quick rip around the back alley and it was glorious.

I'm not sure why I found this intimidating compared to motorbikes, probably just the size difference cause this is way easier to work on than a Triumph Tiger.

 

EXCELLENT! I'm happy you got it working. Now you can refine it to run better and better. Congrats!

 

Yeah I'm pretty jazzed! It's going to need some love and cleaning, it was full to the eyeballs with oil when we checked but we drained it and put fresh oil in.

Only issue now is when we stomp on it the vehicle stutters and almost dies. So going to need to do some digging around what setting I need to correct for that.

 

Good deal. When it stutters out, what is the fuel doing? Too much? Too little? Could be flooding. Good luck.

 

The first question should be is the motor up to temp? If not is the air filter snorkel hooked to heat from the exh manifold and it the flapper valve work as it should? Is this a v8 or 300 six? Both use exh gases to heat the bottom of the intake to help vaporize the gas mix.
The choke may need fine tuning.

If up to temp what is the timing set to? Is the mechanical & vacuum advance working as it should?
Then I would look into the carb accel pump shot and the idle mix settings.
That should keep you busy
Dave ----

 

It's the 300 6, the choke definitely needs some love. and I need to get it through my friends head that these mechanical chokes need fine adjustment, not all the way one way and the all the way the other.

The motor seems to do worse when it gets up to temp, we need to replace a couple of the vacuum hoses on the air cleaner as they're brittle and rigid.

Question, there is a vacuum line that comes off near the choke adjustment that was capped off when I received the vehicle, does that need to go anywhere specific? I've not found anything clear about it.


The mix settings are on my list to work on, any chance you know of a good document or youtube video on adjusting the settings? It smelled like it was running super rich last night.

We seem to be penduluming back and forth between it running beautifully and it stalling out randomly so we're definitely not there yet. Plus it's deadly icy so I nearly went under the truck last night just before we called it.

 

The threaded nipple near the choke housing needs to be capped if not in use. That goes to a metal tube that should connect to the exhaust manifold It's a long story and there is a good thread on Gary's site, and possibly here too. For your testing purposes, I would cap it for now. You can wor out how you want to run that later. It will make a small vacuum leak if open.

Ultimately that tube would feed heat to the choke housing to close the choke faster. See photo to see if it helps you identify any of the screws and parts. I'm kinda lost on the actual screws on the Carter.



Have you got the truck warm enough to know if you are off the choke high idle? I just can't imagine working in the temps you are and the truck warning at all. See if this link helps at all. I hope they allow a cross link to Gary's. https://www.garysgaragemahal.com/carter-yfa-1bbl.html. There is a choke page too that has a diagram and explanation of hte hot air tube.

 

The choke really doesn't work properly without that heat tube hooked to it. When it's cold and you adjust the choke enough for the engine to run properly, then the choke never opens like it should. So then you adjust the choke more open, and then it never shuts enough on a cold morning for the engine to start and run properly. The heat going to the choke makes these problems go away.

 

You are a little off on what you said.
It should not be capped and the amount of vacuum leak is nothing because when the metal tubes are hooked up as they should be it is pulling a vacuum of clean air from inside the air filter.

Also till you get the metal tubes in place like the factory had them you really cant get the choke to work 100% as it uses the heat from the tubes & the electric to OPEN the choke.

You already know the choke adjustment and in the picture above the curb idle speed & fast idle speed screws and on the other side there should be a screw down near the base and that does the idle air / fuel mixture.
Once the choke is off all the way and the (curb) idle speed set you can then adjust the mix screw for best idle speed.
You may need to lower the idle speed when doing this adjustment but most of the time not.
They say you can use a vacuum gauge to adjust the mixture and timing but I have never used a gauge for that.
Dave ----

 

Yes, you definitely need the heat tubes hooked up to be able to drive the truck and choke to work properly. But for testing and getting it going, I'm figuring they can open choke manually when it's warm if necessary. Got to get it to run where he can put it in drive and the truck not stall.

As for capping or not, I've seen so many people say it should be capped if not used. But doesn't seem like it's very much vac leak with it uncapped.

I have been using a vacuum gauge lately. It was $15, so I'm getting my money out of it! LOL. It helps fine tune. But can also be done by ear. Haven't mioved to timing with vac gauge yet.

 

On the carb idle mix setting I am old school, done be ear.
Same for the idle speed and if I have to mess with timing and dont have tools out, tach & timing light, they are be ear also.

Lately I have been using the timing light & tack (in truck) as I am working on the timing curve to stop the pinging.
I do know my idle speed it a little to high but I have to remove the air filter to do this and that is work to get it off.

But what ever works for the person doing the tuning work then go for it.
Dave ----

 

That would potentially explain some issues we had where it would run really well but then either be stuck open or closed. I'll do some reading on those other posts now.

That picture is a big help and I'll root around for that thread but it's odd, the screws on my carb and the screws on that picture aren't all in the same place at all. As you can see in this picture, it looks like the curb idle at least is on the opposite side.


I'm uncertain as to where the line for the choke needs to end up as you can see in the picture below it just kind of stops, it was capped but we removed that and should put it back for now. Would it go in that hole on the manifold that has the square bolt in it? I'm at a bit of a loss as to where a metal line would go otherwise.

 

On the back side of the exh manifold between the intake runners you should see what might be left of the heat tube.
There should be 1 on the bottom side also.

There is a tube that runs inside the exh manifold that gets hot with the gases flowing by it.


See that nipple up top where the air filter sits? A short hose goes from there to a metal line that goes into the bottom of the exh. manifold.
Then a metal line comes out the top of the exh manifold and goes to the choke housing. This line should get hot and should have a insulating sleve on it to keep it hot.

Doorman makes a kit to repair the lines as they rust away most likely like yours did. This is the kit less the copper tubing.

Now if the tube going through the exh manifold is in good shape and the Doorman kits tubing is not long enough get some copper tubing that will run from carb to manifold (cold side) and manifold to carb (hot side) and use the other fittings to make it work.

Now why I have the copper tubing?
I am running EFI exh. manifolds 3 into 1 x2 that flow into a Y pipe.
The EFI dose not have a choke or any way to hook up a hot air line to the choke on my trucks carb, so I had to come up with something.

My fix was to use the copper tubing and wrap it around 1 of the manifolds a few times to get heated.
Cold side of carb like yours would be

The wraps around the manifold

The hot side with the insulting sleve hooked to choke

Now when it got pretty cold here, think it was below 40*f the choke would not open all the way so I leaned out the choke adjustment a little andit helped some but it still stayed on fast idle.
I believed the hot side was not getting hot enough. My fix was to use header wrap around the copper loops to help heat the line and so far its been working.

If the line through the exh manifold is bad maybe you can do the copper tube wrap around the manifold?
The other thing some have talked about is the electric part of the choke. This is not a 12 volt choke on this carb but a 6 to 7 volt cap.
It gets its power from the ALT stater post, it puts out the 6-7 volts and where the factory gets its power from.
So if the copper trick cant be used maybe get a full 12 volt cap to replace the 6/7 volt one and run 12 volt when running to it.
Dave ----

 

HOLD THE BOAT BATMAN!
You are north of the boarder in Canada right?
I dont see a EGR valve between the carb and intake.
Also why I see the "Hi Output" heater.

I wounder if that is why the carb screws are in different places?
They all should work the same other than is different places.

The choke stuff I posted above should be the same.
Dave ----

 

Ooh, that makes sense. I have a bunch of copper tubing so that would work fine and probably be a lot easier than trying to rig something back into the manifold. I'm going to have to climb in and look around now to get a better handle one it.

There is no electricity at all on this choke so I would have to buy something aftermarket if I wanted to go that way, I feel like wrapping some copper tubing around the manifold the way you have would make more sense though.