TWO-BARREL CARB ???
 

My 1972 F-250 HI-BOY V-8 has a 2-barrel carburetor.

On this carb is a Ford re-man decal.

On the front face of the carb is what appears to be a diaphragm lever-operated pump.

The area around this gadget constantly drips fuel --- drip-drip-drip.

Also, it is nigh impossible to keep the engine running until it is thoroughly warm.

I bypassed the old mechanical lift-pump with a Holley "RED" to help keep fuel available at the carb.

Still, I have to "prime" the carb with a squirt of gas or no amount of cranking will start it.

Give it a squirt and it immediately starts, runs a second, then dies --- regardless of what I may do to try to prevent it dying.

Crank all you want, it won't start again until I give it another squirt of gas, which will allow it to immediately start again---run a second- then die.

I repeat this process probably thirty times before it will run without dying.

All the while, the pump-thingie on the carb is drip-drip-drip; it appears to possibly be coming from the gasket, but it is hard to tell.


I would just like to be able to move this truck around on mowing day and use it occassionally to haul stuff around the place, without it being a complete act of congress.


The automatic choke does snap closed when the throttle is depressed; I don't know if it ever opens.

I have searched, but cannot find a pictorial rebuild procedure for the carb, or any useful info at all about the carb.

Can someone point me in the right direction please ??

Thanks.

the drippy thing is your accelerator pump. your daphram has a crack in it.

very common part, very easy to replace. go to the parts store & tell em you need an accelerator pump for your truck. It works like a squirt gun & actually sprays 2 little steams of fuel into your carb throat every time you depress the gas peddle.

there is another square cap on the bottom front side of the carb without an arm or any linkage going to it. Inside there is your power valve which is vacuum operated. Under heavy engine load with open throttle there is enough vacuum supplied to the dry side of the power valve to draw the valve open. The wet side or fuel side of the valve is up inside your float bowl submerged in fuel. when it is drawn open by heavy load wide open throttle it helps supply your venturies with aditional fuel beyond what your metering jest supply during cruise loads.

if your accelerator pump is cracked then this power valve diaphram may be cracked as well. It may apear wet around the base of the carb and the truck could either run rich as hell at idle & actually flood out (with a bad PV diaphram crack) or it might have a fluctuating idle that droans along up & down in rpm while the truck just sits there running. It's not hard to change but you do have to unbolt the barb to access it.


that whole cranking thing, hard to say but it sounds like your fuel bowl is draining. (power valve diaphram crack will drain your fuel bowl while your truck is parked.) It may be draining back some from the fuel line to the fuel pump though. I'd check the lines to the pump really well to make sure everything is tight & not leaking. if the diaphram in the fuel pump were cracked then fuel would spray out the weep hole while the engine is running/cranking.

if your fuel pump is wet with gas at all on the outside then you have an issue there.

Many thanks.

Do I just remove the four screws and this gizmo falls in my hand ??

Are springs, tiny BBs, and other stuff gonna come shooting out of there to be forever lost ??





The entire fuel-line, from tank to Holley RED to filter to carb is all brand-new.

There is also a check-valve just ahead of the filter to prevent drain-back.

There is a spring in there, kind of a big one, hard to lose. And there will probably be a little rod about 1/4 dia by about 9/16 in length. Just looks like a little metal dowel or peg. Sometimes this is all one piece & attached to the acc pump diaphram itself but I think most times with these there is a loose one that acts as a push rod between the acc pump lever & the daphram itself.

But that's about it, pretty straight forward & easy.

It sounds to me like your float bowl is draining/drying out though while the truck is sitting parked. It takes a lot of cranking to pump enough fuel to fill the float bowl to the level where your acc pump has some fuel to squirt. If you have fuel in the float bowl (normal) you can pump the peddle a couple times & by doing so you are giving the engine a drink before you even hit the key, then she pops over & the crank is spinning at idle speed, probably at high idle choke speed which really pumps the fuel.

I guess I'd strongly consider replacing the power valve also is what I'm getting at.
It's really the only thing that can drain your float bowl in a relatively short time.

(and that gas is draining down into your oil pan)

Thanks for the help.

Yep, good luck.

You could probably find a You-Tube video about rebuilding Ford 2100 and 2150 carbs. Or check some of the Mustang sites and magazines for aticles with photos. There are alot of them out there, or go to a used book store and look for the old Petersen's Auto Repair book series on carbs and Ford trucks. I have both that I bought in the 70's and 80's.

Good point, I also forgot to mention what might be the obvious anyways. If you are going to do accelerator pump and power valve you might as well just buy a kit.

I recently priced a power valve alone at a parts store and found the valve costed around $19

And they didn't have it in stock, so I asked about a kit, the kit was about $16 and it had the valve in it. Not to mention needle, seat, accelerator pump, check ball, full gasket set etc.

no brainer.

Carb kits
 

I just had to re build a sgl barrel carb for my wifes 67 F100. We found that NAPA had the best price on the kit and it only took 1 day to get it. The nice part is that it was only $20.00.

Also if you search a carb rebuild kit online you will see the part the other guys are speaking of. It kind of sticks out since it is the only part with a rod on it.