choke question for carb guys

[Mach1460]

The ol 69 is starting hard, or should I say has started hard since I bought it. Im a little in the fog when it comes to carbs but I have a good general idea... Anyway right now it takes about 15-20 pumps to get it to start kicking over... now the plate that is directly on top of the carb is that the choke? Because mine is not connected to any thing (see attatched pic) It stays wide open all of the time. When I pull the choke lever in the cab the idle speed rises and it lowers when I push it back in. So is my choke actually working correctly? I thought that the plate in the top of the carb should be closed on a cold start....

Also does anyone know what kind/model of carb this is? It has no label or anything....

 

[Yardape]

That looks like an autolite. See the bracket closest to you in the first pic, thats suppost to hook to the choke, that rod that is sticking up beside it should have a bend in it or something to go through that bracket. Looks like someone built that carb with misc pieces. That looks like the wrong rod for that choke butterfly.

 

[Mach1460]

So that "choke butterfly" is supposed to be closed when its cold/initinal start?

 

[Yardape]

Not totally I don't think. Its been so damn long ssince I have had a carbed engine. I think It is open just a little bit, like a couple millimeters. But it works along side the choke cam that the rod hooks to at the bottom

 

[Seabronc]

The choke being open is why you have to pump so much gas into it to get it started. The engine needs to be a little rich when cold, closing the choke plate does the same thing by limiting the amount of air into the carb. As it warms the choke should be opened untill it is fully open. I'll bet it runs just fine when the engine is up to temp. Yardtape is correct about the linkage, it is not hooked up. You have a manual choke and it should control the opening of the plate from inside the truck. When closed the choke plate should just barely be open about a 1/16 of an inch between the plate and the side of the carb.

Good luck,

>-

 

[Mach1460]

Ill try to get it fixed for now it seems like my linkage is missing a piece that ties the rod to the choke plate so i dont know if ill be able to make shift something that willl work

I have been thinking of upgrading to a 4 barrel any way, any good recomendations on a manifold with good low end tq? How about the holley truck avenger carbs??

 

[Yardape]

Holley Truck Avenger is your best bet I'd say. Take a look at the Edelbrock Performer RPM. Many people use them and are quite happy. There are so many choices, It really doesnt matter what you use, they are all pretty good.

 

[Mark T]

Ill try to get it fixed for now it seems like my linkage is missing a piece that ties the rod to the choke plate so i dont know if ill be able to make shift something that willl work

I have been thinking of upgrading to a 4 barrel any way, any good recomendations on a manifold with good low end tq? How about the holley truck avenger carbs??

My Carb was the first thing I tackled when I got my 73 Bronco, i.e., I tore off the automatic choke and hooked in a manual. After struggling with the cable and linkage binding I figured out that keeping the old Automatic choke mechanism in place worked alot easier (I have a picture). I assume that my 2-barrel is a FOMOCO, with around 500cfm. It seems to be working flawlessly, so my suggestion would be to find a newer version 2barrel (like my own) and install it on your stock intake. Since your Bronco is a 69, and it would be easier to hook it up to manuel choke, you could use an old automatic choke setup and convert it just like mine. I toiled with the whole 4 barrel intake and carb myself until my Brother told me that the exhaust was more of a priority, and my carb was almost 4 barrel cfm anyway. Unless someone knows something else my Carb does not lack in the Gas department, just a suggestion....... BTW my Bronco had not ran in about 5 years when I got it and it starts with "no" pumps

 

[Seabronc]

I toiled with the whole 4 barrel intake and carb myself until my Brother told me that the exhaust was more of a priority, and my carb was almost 4 barrel cfm anyway.

BTW my Bronco had not ran in about 5 years when I got it and it starts with "no" pumps

Basically your brother was right. As long as the 2BBL carb can supply the maximum demand that the engine displacement can put on it at any given RPM, it will work just fine. Having a 900 CFM carb on an engine that is only capable of drawing 550 CFM doesn't help at all. There are things to be said about the advantages of a 4BBL but that whole other subject.

Sounds like you got a great carb there.

>-

 

[Mach1460]

im pondering the 470cfm Holley truck avenger, i have heard so many good things about it, plus according to the math of things 470 cfm should be about perfect for a 351W. its still up in the air I may keep the 2100 for a while anyway if I can find that piece that attatches the choke plate to the choke arm....

 

[Yardape]

The 4bbl will actually be better on gas too, as long as you can keep your foot out of the secondaries.

I would actually go with the 600 or 650 whatever the actual number is. If you can keep your foot out of it, it will still be good on gas. Without the secondaries your driving around with like a 300cfm carb if you think about it. Your 2bbl has 500cfm all the time.

I have always ran a holley 650 double pumper on my cars (I am a Maverick Lover aside from wheelin) Right now I have a '74 Comet with a 302 and the 650 was perfect. I ran low on cash a while back and sold the carb. I bought an adapter to put the old 2bbl back onto the Performer RPM intake. It has way more power off the line but top end suffers severly, and its way worse on gas. If a 302 can handle the 650 with no problems then your 351 will love it too.

 

[Mach1460]

Thanks for the insight. Was your 302 modified? The 470 and the 670 are the same price so I think that I will take your advice and go with the 670 and an performer intake. That will most likely be springtime though..

 

[Yardape]

The only mods are, Performer RPM intake and a Comp 268 cam