my carb on my 77 f150 300 4sp is in bad need of a rebuilt its a carter carb made for motorcraft should i just rebuild it or is there a better carb out there ? im looking to get the best mpg possible i drive this old girl every day i was geting 17 mpg now its only 12. thanks

 

Are you sure it's the carb causing the poor mpg?

Also, is it OE, 1V, 2V, 4V?

If it is the one barrel, I know Pony Carburetors is selling brand new 'Atomizers', one barrel carbs. Not rebuilds, but brand new carbs. Google Pony Carburetors.

 

well your right im not totaly sure if its the carb the engine seems to be in good timing and it keeps spuding like its loading up on fuel, i can smell it the choke ant working. the plugs are fairly new and i took one out and its good and yes its a 1bl carb. im going to check into pony carbs thanks

 

at least a 1000 CFM worth of holley double pumper is neccissary to get fuel in the 300. Get you 40 mpg, and a 0-60 of 7 seconds.

 

your saying if i use a 1000 cfm holley doudle pumper ill get 40mpg on a 300 inline six ?????

 

At least two of them are realy neccisary.

Its a joke. The Carter YFA or autolite 1100 were the original carbs for the 300 engines. They seem to work well for a while then need a good rebuild kit. Ive had all sorts of probloms over the years. They last about two years and then start acting up.
Probloms I've had-Rough idle, lean mix, rich mix, stumble, no idle, etc, etc. They always seem to make the 300 run just not well.

It just went through a phase where it would not idle for a squat. pulled off the fuel filter and sprayed a bunch of carb cleaner into a new filter, screwed it in then hosed the inside down with carb cleaner. Now it works. But the dang thing is always lean at temps below +40F so it stumbles.

They are a very reliable carb but aint no performance piece.

On a full reevaluation of my previous statement a trio of 850 DP's would be the trick.

 

lol i was hoping that was a joke thanks i might try out that autolite1100 that pony carbs has it sounds good

 

The autolite 1100 went on 240s in truck usage and 300s in stationary usage. I have never seen it on a 300 powerd truck. Though I imagine it will work. Make sure they know that it is for a 300 as the autolite carb also wnet on 144, 170, 200, 240, and 250 CID engines. The CFM should all be the same its how the mixture is set that varies.

I would honestly just tank the carb you have and rebuild it yourself. The cost of the carb kit is about $18 and the carb dip-"tank" about $25. A reman carb is going to cost over $200.

The YFA is a very, very simple carb to rebuild and setup. I can do one in about an hour and half.

 

yea that would be the way to go just rebuild it. the autolite 1100 from pony carbs is $400. theres a junk yard near by that has a carter carb ill rebuild that one and still be able to drive the truck thanks for your input

 

Excuse the lateness- just got back on the forum. Find a Motorcraft 2150 and an offenhauser 2-barrel intake or make a 2-barrel into 1-barrel adapter. The 2150 is cheap, parts are available and it's very adjustable. This 2-barrel can be found @ junkyards- but it's getting harder. If this peaks your interest, PM me and I'll give you some things to look for- otherwise...good luck.

 

Why not get a 2100 instead of the 2150. Same carb without all the smog junk on it?

 

ok im considering using a 2 barrel offenhauser intake and a 2100 or a 2150 could this carb be found on and old 302 ford in a yard ?? would this carb make my 300 run and perform better then the carter ? since its a 2 barrel would it hurt my mpg any ?

 

The 2100 is a good carb for 50's-60's technology. The 2150 is the same base but with an added air bleed function. There's a trick for this air bleed for some extra mileage-but I'm not posting it. Whichever carb you use, the trick is finding the correct venturi size. I'm currently using a 1.21 on a 300, but I really feel a 1.08 (which I'm using on a 4.3L Chebby) would be a better bet. Search the web for venturi size CFM equivalents. REMEMBER that if your engine is not for racing that you only have 75-80% volumetric efficiency and find the carb that closely matches it. The venturi number is on the driver side- looking at the carb as if it was mounted. They're getting scarce-Good Luck

 

I don't understand why anyone would put a 2-barrel carburetor on a 4-barrel intake. 4-barrels can actually achieve better mileage than a 2-barrel because the primaries on a 4-barrel are typically smaller than the throttle bores of a 2-barrel. If you keep your foot out of it, you drive on the primaries most of the time and can use less fuel. A 4-barrel is clearly superior, and if you have a 4-barrel intake and you use a 2-barrel adapter, you're taking a step backwards.

I run a 500 CFM Edelbrock on an Offenhauser intake. If you're looking for mileage, the cheapest and easiest route is just to rebuild the Carter you've got on there now. A 4-barrel intake is going to run at least $150 used, and nothing you put on it is going to beat the 17 mpg you got with the 1-barrel.

Also, for reference - the 2150 is not a smog version of the 2100. The 2150 is very similar to the 2100, except the choke pull-off is mounted behind the throttle body instead of on the air horn. There are also a few added functions such as a high-speed pullover system and a idle-speed temperature compensation mechanism in later models. You typically see a throttle-actuated bowl vent valve on 2150's, whereas the bowl vents to the atmosphere on a 2100.

 

That sounds like smog equipment to me. The 2100 is a great carb though.