MTFCA Forum

My 23 TT is missing the carb adjustment rod. I've seen various setups, some with linkage and others just with a rod with a two pronged end. What do I need and where does it come through the firewall and what is on the other end of it?

The carb adjustment rod for cars goes through the slot that’s on the firewall. If the TT metal firewalls are like the cars it would be the same location. It’s about a 1” or so long. Others that have a TT would know for sure.

You will need the one with the forked end. There is a slot next to the bell crank for the choke that it goes in except you are missing the bell crank too! You have to reach over/under the dash to adjust it. There is an art to installing them, pretty easy once you figure it out. Unless someone else post some pictures I will try and get some of the workings later today.
Re John's comment, same as car on the TT.

To keep it stock '23, you first need to rivet the bell-crank on the firewall so you can fit the short choke rod with knob into the dash from the bell crank.
A wire you make from welding rod goes from the bell crank to the carb choke butterfly lever.

Then you need the long adj. rod, fork end to the carb adj needle valve top, then the loop-end extends into the slot of the firewall, and extends a short way up under the dash. That is if you have a body with dashboard to fit to the firewall.

The adj. forks are made reproduction but are too big at the loop end, so you have to reshape to twist it vertical and then vertical down as you slip it into the narrow slot in the firewall. See differences here:
One on the far right is too large loop reproduction.

I'm not exactly sure what a bell crank is?

So the curved loop of the adjustment rod goes through the firewall and that is what you turn? I really don't have a dash, just the firewall. I've seen pictures of round knobs on the dash but not the curved loop.

The only choke I have is the rod that goes though the radiator that I pull to prime the motor, is there supposed to be something else?

Bell crank is the bracket with two arm on it. The arms pivot up and down.

See bellcranks on left side of firewall.


The wire to the radiator is one half of the choke system. The other haft lets you sit in the seat behind the wheel and choke the engine when using the starter motor. Add that half with a wire to the bell crank, from the lower part of the NH carb choke lever, it has two holes for that reason, that lever for the carb is also a bellcrank in action to move the butterfly.

With no dash panel, no worries, just place the rods thru the firewall and use the knob and carb adj. rods that poke up. You may like to shorten each so that they don't protrude so high in the air.

Here is a close up of a TT with no dash panel, but running with choke rod in driver's reach and carb adj. rod in driver's reach.

Photo is blown up so detail isn't there but you can see the owner used the bell crank, added pull wires, and used the choke knob rod and carb adj. rod just extending thru the firewall.


Arrow trying to point out the slot to fit the yoke or loop end of the carb adj. rod. The bell crank has its choke rod going thru the firewall the other firewall slot. That rod is short with an alum knob on the other end. The rod is held with a cotter pin to the bellcrank, as the rod has an L end there.

Photo shows the two parts you will need, other than the bell crank and some wire, coat hanger wire can do, but weakens quick when you bend the ends.


Choke rod with alum knob, it is very long to reach the dashboard, but easy to shorten, by cutting off. The repro is easy to work with, the alum knob is held on with tiny cotter pin, remove it, saw off the rod to length you need, then reinstall the knob!

The long looking loop with fork end is the carb adj. rod, you will use it the stock length. It extends just above the firewall.

Here is the loop end of the carb adj. rod extending under the dash. You can see it sticking out of the firewall in the slot. Note the rod beside it, that is the choke rod, it is going to the top of the dash, but you would just terminate it to be just above the loop of the carb adj. rod. That way you have clearance with your fingers and thumb to turn the loop. Yes, you turn the loop clockwise to lean, and couterclockwise to rich the carb. You will pull on the choke rod to choke the carb. Be sure your NH carb has a good return spring at the choke lever, that is very important for the action to work.

Here is my 23 TT. Not sure its 100% correct.

So I won't need a bell crank as I don't have a dash?
https://www.modeltford.com/item/4583.aspx

I'll need this choke rod?
https://www.modeltford.com/item/4588G.aspx

And this carb adjustment rod?
https://www.modeltford.com/item/4129A.aspx

Yes and Yes.

Yes, you need all the parts you posted.

And yes, you do need that bell crank, you have a metal firewall, that is where the bell crank rivets. You must have it to work the choke rod.

The bell crank isn't fastened to a dash panel, it goes on your metal firewall on the engine side.

The bell crank turns pulling into lifting for the choke. You could shorten or make your own like the one Dallas shows. The connection between the BC and carburetor, the lower hole on the choke lever is used for pulling from the inside, the upper for wire thru the radiator for hand cranking. I think it would be too steep of an angle to try and use without the bell crank.

Clear side view. It's the "L" shaped metal on the firewall which, through pivoting, changes a 45 degree pull at the dash, to a vertical pull in the engine compartment as well as slightly increasing the choke lever lifting movement relative to the "pull" movement

Someone will have a very rusty firewall which they will sell you the bell crank off of...just ask in the want ads...

When you get your dash and firewall set up there will be times to adjust the carb setting. A thing to remember is to leave the carb nut just loose enough to screw in the carb needle valve to bottom out securely. Not to tight though!!
When you start backing off the needle valve with the adjustment to 1 1/4 to 1 1/2 turns out THEN tighten the needle valve nut to hold it in position.
You can get incorrect settings when trying to adjust the needle valve when the nut is to tight. You will think it’s bottomed out when it’s really not. A half a turn can make a difference in getting the correct adjustment.

May be a silly question but if you have a non starter car or truck for that year do you still have the bell crank? Knowing Henry, I would expect only starter equipped cars to have the bell crank as it serves no purpose if you don't have a starter.

Russ T Fender wrote: ↑

Sun Mar 29, 2020 4:49 pm

May be a silly question but if you have a non starter car or truck for that year do you still have the bell crank? Knowing Henry, I would expect only starter equipped cars to have the bell crank as it serves no purpose if you don't have a starter.

Humm? I don't have a starter.

Steve Jelf has or had a '24 non-starter TT. Hopefully he'll chime in soon with some answers re: bell crank etc.

Humm? I don't have a starter

From the photo of the alternator on the block assumed your engine has one or a place for the Ford starter. In the case of starter TT's later to '24, the firewall would have the bell crank to allow choke from the driver seat. Later TT's were sold without starter but with only block off- plates, so starter could be added, with a battery bracket on the firewall and foot switch, all found in the T parts available . The earlier TT may have not had that bell crank as they had non-starter blocks for a longer time to use them up.

Once the new style combination carb/choke assembly with swivel type carb adjustment, was standard, late 1925, then the #4583 bell crank would not have been riveted to the firewall. The bell crank is listed in the Parts Book among the carb attachments, as it depends on its use with what year carb too.

Ok that makes it simple, just install the adjustment rod. Someday if you add a starter you will want to install the other parts.

Wow, a lot of great info.

Thanks much to all, I'll order the rod for now.......

Just a simple warning here. Unlike modern cars the T carburetor is an "updraft" setup. Meaning that the air and gas mixture has to be SUCKED Hard into the intake to get things started. This means you generally have to choke it to start it and sometimes even when it is warm. Make sure to verify that the butterfly choke valve is fully closed when the choke wire or rod is pulled to operate the choke. Partially closed won't work very well at all and will make the engine appear to be a very hard starting motor. You can't simply look into the intake of the carb since the firewall blocks your view and the hot air carburetor sheet metal stove blocks the view too. You need a mirror to verify that the carb is "completely" closing when you pull on whatever you end up with that is supposed the choke the motor. The most common mistake is when the T choke setup is the typical 1923 version with bellcrank. If the lower pull rod from carb to bellcrank is too long then the upper arm of the bell crank will "STOP" pulling the choke when the upper bell crank arm hits the firewall. To the driver inside pulling up on the choke rod it feels like the carb has the choke fully closed yet the carb isn't choked fully and the engine ain't going to start. You can't see what is going on in the engine compartment if you are pulling on the choke rod while in the drivers seat. Been there. Upper bell crank arm must NOT hit the firewall when the choke is pulled!!. Usually the T will fire up when you are spinning the starter and then drop the choke rod while it is still being spun over. None of my T's will actually start while the choke is closed but it must be closed for an instant and then "dropped" while starter is still spinning and away it goes.

John


Very good advise for sure. Those wires and rods for the bell crank and the choke butterfly and the throttle butterfly all need to be carefully tuned to proper length as you posted. Take care to always check when assembling the carb to the manifold.

A friend with a nice '27 touring came over, he wanted to know why it didn't have much guts when running with the tour crowd. Thought he needed a new carb or maybe a fast accessory carb.

Well, when looking over his T, I pulled the throttle lever at the carb and noticed it didn't reach full stop. Re-bent the throttle rod from the carb to the steering post. He then took it out and came back with a smile.

Seems the throttle butterfly could only go a little open, that was keeping the carb from running wide out, even though the lever under the wheel was down. Easy fix, but simple to miss that the butterfly's on the carb aren't closely fully or opening fully