Boy this problem just keeps poking its head up and it's getting frustrating. It's a Motorcraft 2100 on a 360 and after sitting with the engine cold sometimes it'll just totally flood out and pour gas on the intake. It's so weird because I thought I had it solved by replacing the foam float with a brass one and tried two brand new needle and seats too, and for quite a while it was fixed and didn't happen, but then today it all came back again.

Anything you guys can think of? Is there a little trick with the 2100 for this? The truck runs great once running assuming the carb isn't pouring gas out of it, it's just the initial started when cold

 

What kind of fuel pump? Mechanical or electric? I'd want to measure the pressure. New manufacture pumps are notorious for high pressure. If the pump is OK then take a look at the float height/fuel height.

From reading the different forums and posts going back a few years it also looks like the dry "bench" setting float height often gets confused with the fuel height setting. The float height is just a ballpark, and can be way off in use.

The only one that matters ultimately is the actual fuel height. When the truck is good and warmed up, let it idle for a couple minutes on level ground, and shut the motor off. Pull the air horn and gasket (4 screws) and take a peek at the fuel level.

(Generally - check manual) It should be 29/32" from the level, top machined part of the fuel bowl, down to the surface of the fuel. As it happens, a US $.25 piece is close enough to 29/32" and handy to use for measurement.

 

I've been bitten a coupla times by that return spring that is supposed to keep light pressure on the float. Is yours correctly positioned?

 

I'm not quite sure to be perfectly honest, what are you meaning by the return spring and what would the correct position be? Sorry if that's an ignorant question, I'm still a learner

 

it's a mechanical fuel pump, and actually now that you mention it when I pulled the top of the carb off to flick the float, which is what I got in the habit of doing before ever even trying to start the truck in the past, I noticed that the fuel was higher than a US quarter. Not sure by how much, but just from eyeball memory it was higher than that. I did exactly what you said not to, I just went with dry float height

 

Yup it's one or the other, One being a to high fuel lever.

And Second your fuel pump has to much pressure.

Working on these autolite carb are piece of cake for some of us...

This takes a little skill plus you don't want to have a fire, but many of us guys can removed to top air horn while it's running to check the float level.

But you need a few rags at the base of carb around it to the catch any spilled gas to have control of any spillage fast to keep it off gas off the intake tho..

Do you have the fuel pump filter or any crap getting into the carb??
If time for a gas filter .
Orich

 

The return spring isn't always installed, it's kind of a damper deal to prevent excessive float bounce on rough terrain. You can see it in this pic, stolen shamelessly from somewhere on the web.

I did as Orich mentions and also (carefully!) checked fuel level at idle. In my particular case the the bench setting of the float meant the fuel level in the bowl was real high.

In order to adjust the float to maintain the correct fuel level, it now has hardly any swing. I had sort of envisioned it would work like a toilet bowl. Not so. The pump is constantly supplying fuel steady - and this is at idle - Just get the fuel level right, don't worry about the float level. It's not super critical to get down to the level of the gnat's ***, but it is important enough, also affects jetting and transition circuits etc. A higher column of liquid in a column exerts greater pressure, etc, stuff every schoolboy knows.

 

Well now that's interesting, is that spring something that's supposed to be standard? Mine sure doesn't have that.

 

So how would I go about determining if the fuel pressure is too great, process of elimination once I make sure the fuel bowl has the one US quarter height to it? And if that's the case, which I'm not sure it is yet since I had only done the dry height, not the wet height, what's the next step...a different fuel pump and hopefully it doesn't create too high a pressure? Is there a certain brand/model that is better for keeping the fuel pressure lower? As it would have it, the fuel pump was replaced right before I got the truck. I picked the truck up at an auction and the son of the estate owner had thrown it on there, probably because the truck wouldn't run. Turned out the stuff in the gas tank was less like gas and more like muddy river water. I did three good cleanings before I started getting clean looking gas coming out. I will throw another in line fuel filter on there just to make sure that's not what's giving me hell

 

The anti-bounce or damper spring was standard? Maybe. But not often included today. They are available from a couple sources. 2100 is very popular with offroaders as it is about as close to fuel injection as a carburetor comes. This is important when rock crawling and 4 wheeling at extreme angles. Anyway I wouldn't worry about it in terms of intermittent flooding on startup.

Pressure should be tested with, you guessed it, a pressure tester. Nearly every (all?) mechanic's vacuum gauge made also tests (mechanical) fuel pump pressure. You need one of those anyway. So. First just make sure the fuel level is correct. There's also a clip that secures the needle to the float tang, so that it rises and falls along with float. Sometimes this is missing as well. You can make one out of a bread tie. If the float goes too high can envision the bowl filling too fast (or too high) and soon maybe flooding that way. Just guessing mind you at 400 miles, let us know what you find.

Great carburetors, but sometimes people do some wacky things to them before they arrive in more careful hands.

 

I would check to make sure the gasket on your seat is in good condition, because even if your float is working properly, a bad gasket can allow fuel through while it sits overnight, causing the bowl to flood.



I am basically a learner on all this stuff too. I have learned a couple things off this forum that may help you out.

Pictures, take a bunch. You want pictures to be able to go back to every step you have done, and "see" that it is correct while you come on here and discuss your issues. You want to compare your pics with the ones that are posted here.

Never assume that the previous owner of your truck had it right. I had "fixed" my 4x4 hubs but reinstalled them as I had taken them off. I had taken lots of disassembly pics and put it back the same way. I was able to sit in a comfy chair and compare the pics that I took to the web pics and figure out where I went wrong.

Keep in mind that the guys on here are not making the same mistakes that you and I will make, because they know it. They are assuming everything is correct so far, and the problem is forward. I had run into a problem when I went to do my brakes. The previous owner had swapped the hardware from left to right, and I had put them back on the same way using pictures, so the adjusters were not working at all. I came on here and read posts, asked questions but still had a major problem. These guys were trouble shooting forward, assuming that everything was correct to that point.

 

I had this issue when I rebuilt my carb. The problem was I did not connect the float to the needle valve and connect everything to the carb body properly. There's a small spring/clamp that holds it all in place. Without it the float/needle valve don't do anything.

 

There is no spring in the exploded view of the Autolite 2-V in my 1967 manual.
I have never seen one.

 

Sorry, it's a clip. It's the little silver thing dead center at the bottom of this picture. It holds the float in place and allows it to pivot the needle valve up and down. Without that clip holding the float in place, the float just pops up as high as it can, the needle valve does nothing, and gas continues to flow forever.

Motorcraft 2100 Carburetor Repair Kit K4008

here's a pic of the clip itself.

http://www.carburetion.com/Products/...x?Part=CUD3879

 

So is that clip that slides over the float tang supposed to be tight against the tang like using a pair of pliers once it's in the proper position on the tang, or loose? Mine is loose so it can slip back and forth on the tang.....wich makes me wonder if perhaps when the float rises it doesn't properly apply enough downward pressure to the needle and make it seat all the way because the force gets transmitted sideways instead of downward to plug the hole. Does that sound plausible?