I'm having problems with the carb on my 300 I6. I've got a 65 F-100, don't know if the carb is original but it is a motorcraft. The truck won't hold at idle. If I pull the choke 1/2 to 3/4 back, it'll hold, though not real well. Good enough to drive though. I pulled the carb, cleaned it up, and tried to retune it, but it changed nothing. I assume I have an air leak though I don't know where. I'm just wondering what some of the problem areas are with the single barrel motorcrafts, and where I can go to get a rebuild kit. Any help would be appreciated

-Ben

 

some problems I saw are cracked vacuum lines, and a loose carb. try tightening down the carb. It should run with the choke almost closed.

 

Besides making a fuel wasting gas pig out of a fine piece of machinery, here are a few problems I encountered with my 1bbl carb. Most of the time the choke would not work, float would hang up quite often, mounting nuts would come loose, the screws on the carburetor would come loose, throttle would stick open sometimes, ice up in really cold weather, it was all around a tempermental carb. These problems were minor to me, my main problem with the 1bbl carb was it wasted a lot of fuel and was very restrictive...the engine didn't produce anywhere near the power it was capable of making. My fix was to delete the EGR valve and mounting block, install a block off plate to close the EGR port on the intake, install a Cliffords Holley 2bbl adapter plate, and bolt on a brand new Holley 350 cfm 2bbl carb. It made a huge difference in power and mileage, gas mileage almost doubled; acceleration was greatly increased. I went from only being able to squawk the tires, to being able to set it sideways on dry pavement! I think your problem is the float is hung up. Try tapping on the fuel bowl with a small hammer, it worked for me. My advice is to get a 2bbl holley, it's expensive to set up but it's worth it in the end.

 

As mentioned by Pkupman82, the carb has a tendency to work itself lose. I battled mine for a while and then got fed up and used locktight on all the carb screws and mounting bolts. Knock on wood, I haven't had any problems with it since then (about four months). You should be able to get a rebuild kit from any parts store. I got mine from Carquest, they had it on the shelf. Just remember to write down every number on the carb and take it with you to the parts store. The carb itself is easy to rebuild. Just take your time and save the beer drinking until your done!!!

 

I agree...but would choose the Holley 390 CFM carb instead of a 350 CFM carb. Might as well get what you paid for with that l6.

 

What would be the difference in the gas milage be between the 350 CFM 2bbl and the 390 CFm 4bbl?

 

Depending on the jets you use the 350 may do a little better but, if you jet it correctly the 390 would probably be a better bet for your money. + you get more wot power with the 390 than the 350.

 

1-2 mpg better with the 390cfm 4bbl (and even a 390 is to small, 450-500 works alot better)

 

Would if you were to jet up or drill out the jet on the 1BBL? Would that give you some cheap/quick power? I'm askin this in general, cuz I got that 1BBL on mine and am just about finished rebuilding w/ steel timing gears, bored 60 over, comp cam, moly rings, .015" off the block, .006" off the head, converted to duraspark from TFI, converted to adjustable rockers, but I ain't got the money for the 4 barrel stup right now, I'm not even gonna bother w/ the 2 barrel. So i'm lookin for slightly more power for the time being, the headers and intake can be put on in the truck later.