What kind of carb is this?

[Anonymous]

http://photo.starblvd.net/hillbillyhell ... &ro=2&co=4

http://photo.starblvd.net/hillbillyhell ... &ro=3&co=0

We tried to start our 250 today but it seems there are some problem with the carb. It seems like some of the old EGR stuff might be messing it up. It has a manual choke on it now, but there's all kinds of wirdes and egr junk all over it. We plugged up the hole in the carb spacer that was hooked up to the exhaust manifold, capped off the heat pipe, and capped off the vacum lines. ON the carb it says remanufactured by Holley, and there were 4 numbers on it. "2567" "64-1105" "120010" and "1281"
Any help would be appreciated.[/url]

 

[Anonymous]

Hillbilly Hellcat I believe the carb is a Carter YFA. It is different than a Carter YF in that the throttle plate housing is really short making it good for low clearance applications. The rebuild kit for a Yf and a YFA is the same except for the gasket between the throttle plate housing or base and the venturi body. I have three of them one came from a 1976 Maverick and has no pollution control and doesnt have the extra bowl vent. The other two came from 4 cylinder Ranger pickups and have all the pollution control you have on yours. I plugged up the bowl vent and removed the forked rod from the throttle shaft that operates it. I took off the solenoid on the throttle linkage plugged up the vacuum lines put on a manual choke and plugged up the egr on the carb spacer and got rid of all the heat tubes to the choke etc. If you find the right vacuum line to the distributor it runs quite well. I have used the Autolite 1101 and the Carter RBS and I find the YFA makes the most low end torque and has quicker pickup than the other two. It flows about 193 cfm and if you can overcome all the pollution stuff it runs pretty smooth. Hope this helps--Larry

 

[Anonymous]

What is that line at the top of the carb used for? Should I run lines to that ports in the intake?

 

[Anonymous]

If your talking about the line with the red plug on it as far as I know that is just a hot air line that puts hot air into the venturi probably from a tube from the exhaust manifold. I just left mine plugged. The brass tube in the middle of the venturi is the original bowl vent that all Carters have it just stays open inside your air cleaner. Some of those lines at the base of the carb are venturi vacuum and some are manifold vacuum . you have to decide which one you want to advance your distributor and plug all the rest. The way I found out was I set my timing at say 10 degrees BTDC, then I hooked up the hose from one of the ports. If the timing stayed at 10 degrees and advanced( watch with a timing light) when I gave it some throttle it was venturi vacuum. If the timing advanced to say 20 or 25 degrees at idle by just attaching the hose to a port its manifold vacuum. I ran mine on both and found out it runs best and gets better gas mileage on manifold vacuum. It looks like you have a manual choke. There may be a piston inside the choke housing that works on vacuum. If this particular carb has a piston it will create a vacuum leak if its not sealed off. If there is a piston in there you can remove it and plug the hole with JB weld or some kind of heat resistant epoxy. I followed the casting on the carb from the back of the piston hole and plugged mine in the carb base where it sucks from the intake manifold, the hole is only about 1/16 at that point and is easy to plug. --Larry

 

[Anonymous]

The Carter YFA - Is it cable operated like the one I have? Do I have this piston? It seems like it has a vac leak and it stumbles and sputters when I rev it up, but I cannot find the leak with ether.

Thanx

 

[Anonymous]

Hillbilly- From the picture it looks like your carb has a manual choke conversion. The carb had an automatic choke to begin with and if it wasnt electric there should be a piston that the rod that moves the choke plate is attached to inside the choke housing. Another way to tell is if there is a round part on the side of the housing with a metal plug in it about the size of a dime. This little piston works on vacuum when you start the engine cold the automatic choke is full on at idle then the heat from your heat tube heats up the bi-metal spring and as your motor warms up the choke opens more and more until it is fully open but if your not idling and you accelerate with a closed choke the mixture is too rich and you will stall. As you accelerate the engine vacuum increases and pulls the piston which opens the choke plate to run leaner, let off the throttle and the vacuum decreases and the piston falls back closing the choke plate again. The automatic chokes are designed so that the cap is a very tight fit and they also have a gasket so no vacuum from this piston can suck air in. The manual choke housings( the plastic cap) are very sloppy, they also have the linkage rod passing through the center causing a leak. You can take off the plastic cap and if there is a piston you can unhook the linkage, pull out the piston and plug the dime size hole with JB weld or what ever or you can trace the piston hole (you have to remove the carb) to the base of the carb where you will see 2 or 3 little holes find the right one and plug it. I think all carter carbs YF, RBS etc. with heat rising type automatic chokes have this piston. Hope that is your problem--Larry

 

[Anonymous]

Hillbilly;
The port with the red cap on it is the 'supply air' port for the choke-warming air circuit. In its original form, this carb had an electric choke that connected to a 7-volt terminal on the alternator that supplied 7 volts of AC power when the engine ran. The electric choke's heater will not operate, though, until it reaches about 50 degrees. So, to get it warmed up on cold mornings, there was a tube from this red-capped port that went into the exhaust manifold where a little coil of tubing (3 turns) inside the manifold got heated up by the exhaust. The other side of this tubing came out into a 'heat riser' tube that connected into the choke housing. There is a small passage from the choke housing into the throat of the carb that pulls this heated air through the whole circuit.

The carb appears to be from the 1900 family of Holleys, maybe a 1940. It's not a 1946: it appears to be older than that.

 

[Anonymous]

Im sitting here with the identical carb as yours in my hand and it is a Carter, however after looking at the far side of your picture Im sure yours is a later model and instead of the piston vacuum advance on the choke plate you have the external vacuum which is a diaphragm that is housed in in about a 2 inch round and 1 inch thick probably gold colored housing located by your choke housing on the engine side of the carb. if this were hooked up it would have a thin wire that connects its lever to a lever on the choke plate shaft between the choke housing and the venturi. It acts in the same way as the piston opening the choke plate under throttle and closing it back at idle until the engine gets warm. You just have to plug off the source where the hose to this diafragm came from and if you want you can remove the diaphragm completely. that tube with the red cap could have something to do with the choke you dont need it any more but keep it plugged so your carb doesnt suck in dust. The big ugly tube that comes out of you choke housing is the heat tube from your exaust manifold, you can remove that and put a plastic plug in the hole to keep crud out of your choke housing but you dont have to plug it. Also if you dont want to use the solenoid throttle modulator that the throttle lever hits on you can remove that along with the plate that attaches to it and the thing will start looking like a carb. Im not sure but maybe its Doug Leach (is he Mustang Geezer?) that has a website that shows a carb setup with two Carter YFs, if you have a look at those carbs you will see they are very similar though not as sophisticated as your carb. I also had a vacuum leak when I put my carb on. I finally found that even though it looked like new one of those little rubber plugs was a bit loose on the pipe and was sucking in air. Hope you get the carb working--Larry