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Help understanding carburetor

S

Stephen Newell

Well-known Member
I have a 75 Jeep CJ5 which has a Carter YF carburetor on it. Recently I rebuilt the carburetor and it started pouring gas from under the bowl somewhere out on the motor. I decided I did something very wrong so I bought another rebuild kit and had the jeep towed to a garage and had a mechanic rebuild the carburetor. Now it's worse. It now only leaks gas out from under the bowl it blows gas out this tube on the top too. I've got another kit ordered and was wondering if anyone had an idea what we are doing wrong.
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Just guessing, either an incorrect float level setting, or the float isn't floating. Is the float made of brass? Or is it made of a composite material? Sometimes those composite floats become saturated with gasoline, and then they DON'T float.
 
I'm one of the LAST people who should be writing here (not an engine guy!), but there "should" be a gasket where your white line is, right? If the mating surfaces are not clean and smooth, that could allow gas to leak out.

It's getting more and more difficult to find professional mechanics that even know about working on carbs anymore. Most everything nowdays is EFI. :evil: However, ANY mechanic should know to ensure that mating surfaces are smooth and clean for gaskets - which is why I'm fairly certain that isn't the problem.
 
It's been a couple decades since I built one of those but my guess is you missed the ball and pin in the center.
 
I tried to rebuild a "simple" one barrel carb on a Ford Falcon years ago. Dropped a little ball out of the carb and it went I don't know where. Ended up with a new rebuilt carb. So beware of parts that fall out unknown to you. What was it doing before you tried to fix it? just my experience. not much help. gobble
 
I have a table with a raised lip around four sides to work on something like that. The jeep was running good before I started working on it. The only problem is when sitting for a long traffic light or stuck in traffic it started blowing quite a bit of white smoke. I thought it couldn't be good for the engine and especially fuel economy so I thought I would fix it. At the time gas was running 3.50 a gallon.
 
I don't know about now but when I worked on the carburetor I spent more than an hour and a couple cans of carb and choke cleaner cleaning everything. There shouldn't have been any debris. The gas passes through two fuel filters before it gets to the carb.

I have the hardest time though understanding the directions on the kit on how to set the angle of the float.
 
are you running an after market or electric fuel pump by chance??? if your fuel pressure is too high it can blow right thru the needle and seat in the float and flood the carb. holleys were bad for that. 4-6 psi and they were happy. put a gauge on it and see what your pressure is. you may need to run a regulator.
 
The trash idea was just something to check. Most repair kits have a small ruler like gauge. You measure from the top of the float. To the top of the fuel section of the carb. It can be different with each carb.
 
A lot of talk about missing ball, but that should be check ball for accelerator pump, so should not affect this.

I suspect you are blowing through needle and seat, either high pressure (unlikely that changed), leaky or binding float.
 
Somebody correct me if Im wrong, as its been probably 20 years since Ive dealt with one of those - Is the hose with the clamp the supply line? If so, shouldnt it be on the other port? Seems like the ones Ive worked on had the filter that screwed intothe other port, maybe a newer version??
 
What I'm using is a mechanical pump like the jeep was originally built with. I don't have the means of measuring the fuel pressure. I will have to see about getting a gauge.
 
here a link to one type. your system is not high pressure like an injection system, so a simple vaccuum-fuel pressure tester will work fine.
poke here
 
(quoted from post at 12:57:56 06/21/17) WHITE SMOKE = ANTIFREEZE being burned. -- Just saying.
Click to expand...

Was gonna post that as well. Black smoke = rich fuel/air mixture. So now you've gone and created a problem that wasn't there to start with and you still need to figure out how anti freeze is getting into the combustion chamber.
 
Hello Stephen Newell,

How did you test the float?, as you said it is not leaking. They do develop microsopic cracks and get filled with gas. Hold it in your hand and Shake it. It also should float in a bowl of gas. Side clearance in the bowl, and a free hinge pin is another spot to check. Lastly check the float drop and its height is also important. Rule of thumb for the height, is float level with the air horn upside down.

Guido.
 
It has to be something else than antifreeze. I'm not loosing coolant and it's been doing that for nineteen years. It's just more recent I'm caught in a traffic jamb which is usually when it does it. It's very possible I could be getting water in the gas. I've had a lot of problems with the plastic floats in the gas tank sending unit leaking so I never know how much gas I have. It has two gas tanks which I try to just use one in case I run out of gas.
 

Take the top off roll it over and apply vacuum to the fuel inlet does it hold a vacuum... Even better can you come up with away to apply 1/2 PSI to it and check for leaks around the seat and needle.

You could apply a gravity fuel supply to it and check for leaks... Its basic diagnostics you just have to get the machine between your ears operational...

One more thang make sure the float bowl is vented... If its not the fuel pressure will pressure the bowl and fuel will find its way out :shock:





Nutter tip

Google

Carter YF carburetor

Click on Images

Find a image you like and click on it, once it pulls it up double click on it, it will pull up the original link to it like this.



http://www.hansenwebdesign.com/truck/facts_carter.html

http://jeeptalk.net/index.php?showtopic=14950

https://www.youtube.com/watch?v=SD4zs7VOp7Y

And many more even you pix was there...

I cheat I have a redline evap tool it will nail a leaker in a heartbeat...
https://redlinedetection.com/
 
Lot to digest. Thanks for the links and info.

Where the body is leaking gas I suspect there is a leak around the throttle rod. I know it's not the reason for it discharging gas but I think it may have a vacuum leak there.
 
(quoted from post at 05:58:56 06/21/17) You need to stop buying parts and start troubleshooting!
Click to expand...

Hey, he is buying rebuild kits, not carburetors, fuel pump, fuel line, gas tank etc.
 
What I've been through the thought crossed my mind to buy a remanufactured carburetor. The three hundred bucks set me back though. Anyway I really need to learn how to I can repair and maintain this carburetor.

The parts really don't matter. If it's determined I replaced a good part the old parts go into a box and put on a shelf. Parts for that jeep are getting more and more scarce so some day I when I have a dreadful time trying to find a fuel pump or something I will have one on the shelf.
 

If you want to find a mechanic that knows carbs, look for one with grey hair.

I have grey hair; you have something wrong with the needle and seat sealing the float bowl to the correct level.

10 years ago my neighbor rode his Kawasaki 4 wheeler over to my house. Gas was dripping out of the carb.

We got the carb out, I carefully pulled the float bowl and found a flake of rust in the seat, showed him what was causing the issue and we put it back together.

OP, to bad they didn't put a Carter Thermo-quad 4 barrel carb on. When I was in tech school, I asked the instructor which was the hardest 4 barrel to pull down, reassemble, and make all the adjustments. TQ had 17 adjustments!!!

I was never intimidated by a carb after that. I could get Ford Variable Venturi carbs to work.
 
Actually the guy I took it to had gray hair. I had done the carb myself before in 1998 but didn't quite get it right. This last time when really bad is why I took it to a mechanic. I wish these adjustments were on the exterior so you didn't have to break it down every time.
 
They were always aggravating devils. They made them rat here in my home town. I use to go the the local salvage yard and get new ones they were guaranteed scrap but a guy there looked the other way :D

A nice upgrade is a Weber with electric choke. You can go to Reline web site and get the low down. Redline is great to work with. BTW those Webers are made rat here in Sanford, NC.
Best of all there is a little performance advantage to the Weber.

I have gray hair it would not make me mad If I never had to work on a carb again :) Not that gray hair has anything to do with it the money is in EFI... I work for the money others can have the glory...



http://www.morris4x4center.com/webe...Pp2H3TiSMCYV_jPMSxoC1v7w_wcB&gclsrc=aw.ds

http://www.redlineweber.com/carb-kits/
 
My experience with YF's is on Fords and they look a little different than your picture. However, I believe they all have the accelerator pump in the bottom of the float bowl. If the diaphragm is torn or otherwise does not seal fuel leaks directly to the inlet manifold. There is a procedure outlined in the kit instructions to follow when installing. I install one every few years in my wood hauler, when ever the engine goes dead rich.

My brother had a rebuilt that never worked. He asked me to take a look at it - he had actually plugged the accelerator pump channel to stop it from leaking. That may have been one problem but the real problem was the float. It seems there are several floats for those (at least on the Fords) carburetors but no one seems to know how to determine the correct one. I bought several from NAPA to find one that did not interfere at the top with the bowl cover. As has been posted; turn the carburetor upside down and test for the needle valve sealing off.

Also, make sure the fuel bowl is vented, check for a gasket covering the hole, improper hose routing, etc. If the fuel bowl is not vented properly fuel comes out the top, regardless of the needle valve sealing.
 
To add to what Ken has. I too have my experience on Ford YF. Just put a new pump diaphragm in my 68. Old one was pin holed. New one from NAPA was so thin it would not seal in the casting. Took edge of old diaphragm and cut off edge to use as a gasket, sealed right up. Dug around in my old kit stuff found a gasket in an old jiffy kit that was made to use on that pump. HTH Tom
 
Update: I bought a vacuum/pressure tester and the fuel pump tested to just over 4 psi. Then I checked the vacuum pressure to the distributor and it tested 0. There is no vacuum pressure at all. The external leakage of gas is coming from where the throttle rod comes through the body below the bowl.
 
Well, the first thing I'll tell you is that you're going to find every mating surface on that piece of junk warped. But that is not going to cause your flooding problems. Any surface you can, flat-sand it; I have a flat stone that I stick some 150-grit emery cloth to for this. A glass table-top works too. The ones you can't, that have non-removeable protrusions, touch up as best you can with a hand file. Then post some close-ups of the needle/seat/float assembly as you put it together; do one step, post the pics, we'll check your work as you go. Several of us here have had extensive experience with carbs, Guido, El Hombre (the only other guy I know that claims to make Ford VV carbs work), myself, others--Somebody's bound to spot the problem(s). It'd be much quicker if we were in the same room, but...
 
Oh yes. You shouldn't have any vacuum to the distributor at idle, the vac advance doesn't kick in until the throttle is opened at least a bit. Constant vacuum to the distributor was Chevy's contribution to the automotive industry, and the bane of emissions inspectors.
 
Ok, I've got the carb off the jeep now and opened it up. I don't know if it was the right thing to do or not but the mechanic just used gasket sealant on one side of everything. According to the instructions with the kit the float appears to have been set right however I can't find any specifications as to where the float should be set. The manual I have just says use a gauge.

The metering rod will seat all the way down only if you depress the diaphragm. Otherwise the set screw will stop it. It has a range of motion of 1/8".
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First, don't take anything else to that "mechanic". No sealer should ever be used in a carb.

I can't really tell from the pic, is that a spring-loaded needle? Is that held horizontal? My point is that there is something wrong with the geometry of the float and needle, the float lever should contact the needle very close to 90 degrees. That looks about 70. Try holding the carb top so that it's just off vertical, with just enough gravity to make the float touch the needle, and not compress the spring (if there is one) inside the needle. Remove the seat, make sure there is a gasket below it, and the body is not cracked right there. Obviously make sure there is nothing in the hole, make sure there is a rubber tip on the needle, if there is supposed to be a tiny spring in the needle make sure it's there.

The metering rod isn't supposed to seat unless that diaphram is depressed. There is manifold vacuum under that diaphram, when you have good vacuum the carb leans out the mix, put your foot in it you lose vacuum and the carb fattens it up for max HP. Simultaneously the gasoline on top of the diaphram is pumped up through the accelerator pump nozzle to compensate for the fact that you just added a boatload of air pressure to the manifold and some of the gasoline just puddled in the bottom of the manifold.

Again I can't tell, is this one with the plastic pipe from the diaphram housing to the body for the accelerator pump?

Hold a ruler up next to those two ears on the main body where the top screws on. Bet they're not close to flat.
 
Yes it is a spring loaded needle and it is held horizontal. The camera didn't focus right when I took the picture. Inverted the top of the float is very close to horizontal with the top of the carb. It measures 11/32" next to the needle and 3/8" at the outer edge.

With this carburetor there is no plastic on it at all except for the choke cover.
 
Try to hold the carb top so that the float hangs down and just touches the needle, without compressing the spring, and the needle tip just touches the seat. Get a pic of that. That is the position at which the adjustment of the float level should be made. In the absence of specifications, with the top of the float parallel to the carb surface below it, the carb should make the car run. Take a new piece of fuel line, connect to the inlet and blow into it while tilting the carb top; you should be able to feel it shut the airflow off. BTW the carb kit should come with specs. Also, a very tiny piece of whatever is enough to cause that needle-seat valve to leak. One hair will do it. Did you look for a gasket under the seat? That is, between the seat and the carb top?
 
On this model the needle is inverted in the top. When the float raises toward the top the needle is suppose to cut off the gas. This is why I showed it inverted so the needle should have been closed. In any case I found what was done wrong. The spring for the needle seat was used on the weight-check ball. It doesn't explain why the carb was doing the same thing when I did it though.

This is still very confusing. The instructions with the rebuild kit tell you to measure this and measure that but they don't give any specifications as to what the measurements should be. I think I could do this by the instructions if they were complete.

Good to know about not using gasket sealant. When I bought the jeep who ever worked on it used gasket sealant on both sides of the gasket so I've been doing it myself. This is why I've been buying rebuild kit every time I go into it.
 
(quoted from post at 13:01:33 06/24/17) Yes it is a spring loaded needle and it is held horizontal. The camera didn't focus right when I took the picture. Inverted the top of the float is very close to horizontal with the top of the carb. It measures 11/32" next to the needle and 3/8" at the outer edge.

Stephen,

A float mis-adjustment will cause the fuel mixture to be either a little rich or lean. However, it is unlikely to cause the flooding problem you described. Yes, the float top is and should be horizontal with the top of the carburetor. However, the metal tab should contact the needle valve at a right angle. When the float compresses the needle spring as indicated in your picture it suggests the float has absorbed gasoline and is heavy. Heavy floats don't float so well and can cause flooding. Several weeks back I was trouble shooting a rich condition with a carburetor. The float looked the same as your picture after the level was set. That float weighed 12 grams and was fuel soaked. The replacement float weighed 8 grams and corrected the rich condition.

The float can be tested by placing in a jar of fresh gasoline. The float should float like a fishing bobber without a sinker on the line. Place a lid on the jar and wait 2 -3 weeks, then note any change in how much of the float is above the gasoline surface. Any change indicates a faulty float. The 12 gram float I spoke of above, had sunk to the bottom of the jar after 3 weeks. If you don't have 2 - 3 weeks simply replace the float. Plastic floats are known to go bad.

Have you tested the needle and seat to verify it seals? A simple test is to blow into the fuel inlet. In your picture with the float face up, install a fitting into the fuel inlet, then with your mouth blow into it. The needle should be sealed against the seat, no air should flow. Continue to blow and turn the carburetor so the float falls away from the needle. Air should flow as soon as the float moves away form the needle. Continue to blow and turn the carburetor so the float is up again. No air should flow once the float contacts and pushes on the needle. Repeat this test with the carburetor fully assembled to verify the float is not hanging up on anything. My brother's YF failed this test due to an interference with the carburetor body.

Report back if you still have problems.
Click to expand...
 
Yeah, an overweight float is one thing I was getting at. I'm also thinking that the "mechanic" that was last in it set the float level with the spring compressed, overweight float or no. That accounts for the weird geometry between the float and needle. With that kind of angle of attack, it's quite possible the float is pushing the needle sideways enough for it to stick. And if the gasket under the seat is supposed to be a thick one, and is missing, it could account for all of it. This is what makes long-distance diagnosis difficult. Stephen, do you have a scale to measure the float weight? Again, all these specs should be in the carb kit, usually on a separate sheet from the actual instructions. And please, post the pics I asked for.
 
You say you don't think the float is responsible for the carb pouring gas all over the engine. What would be your guess as to the cause?

Rather than testing the float right now I may see if I can find a replacement.

I never knew to test a needle valve like that so that wasn't done. I will give it a try tomorrow.
 
Tomorrow I will weigh the float. It's light as a feather, I don't think it's saturated with gas.

I have the instruction sheet that came with this last kit. It's the only paperwork that came with the kit and there is no specifications in it. I think I have the paperwork from the last two kits. I will see if there is any specifications there.

This illustration is one of the ones left blank. It says measure the clearance between lower edge of choke valve and air horn well but there is nothing anywhere with the dimension.
a163890.jpg
 
I'm used to seeing a whole sheet of specs along with a general instruction sheet. The exact specs usually differ between carb numbers, so you might look for that too. IIRC Carter stamps them into the body, rather than Ford's bad habit of a removeable tag, so it should still be there. If you can't find any with your old kits, maybe some friendly local auto parts store would let you copy one of theirs? But as I say, minor adjustments are not causing the carb to flood like that. If the float is very light, I suspect it's bent so far out of whack that it can't close the needle valve properly, or there is crud in the needle/seat. All these things need to be right. Your instructions should also tell you that you should hold the carb top vertical while measuring/adjusting the float level, and horizontal with the float hanging down to set the float drop.
 
The float I weighted it and let it sit in a bowl of gas for an hour and either way it weighed 8 grams. The seat for the float needle is clean. It was the new one that came with the kit. I found the old one in the box and the old kit did have a specification sheet with it.
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This is the main thing I'm talking about.
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If you can't achieve this, SOMETHING IS WRONG. Wrong needle, seat, float, missing gasket under seat, SOMETHING, and it needs to be fixed before you ruin your motor.
 
(quoted from post at 19:29:00 06/24/17) You say you don't think the float is responsible for the carb pouring gas all over the engine. What would be your guess as to the cause?

Rather than testing the float right now I may see if I can find a replacement.

I never knew to test a needle valve like that so that wasn't done. I will give it a try tomorrow.
Click to expand...

Stephen,

- I did not state, I don't think the float is responsible for the flooding. But rather stated a mis-adjusted float should not cause flooding. That is to say, test the needle valve for sealing and do not worry about the adjustment at this time.

- I did not mean to imply your float should weigh 8 grams. The 8 grams was a comparison between a new float and the existing float that was confirmed to have absorbed fuel. BTW -
the 8 gram was the weigh of a float assembly with two floats. Your float assembly only has the one float.

- I did not mean to imply your float is good if it floats for one hour. I specifically stated a test period of 2 - 3 weeks. The faulty floats will absorb fuel slowly over time - not like a sponge submerged in water.

- Yes, replacing the float is a good idea considering the problem you described.

- To your question, what do I suspect the problem is? 1) A needle valve/seat assembly which is not sealing. Testing by blowing into the inlet with your mouth will test for this and also verify the float is not hanging up inside the carburetor. 2) A faulty float or incorrect P/N float. Replacing the float should address this. 3) A faulty or leakage around the accelerator pump diaphragm. 4) The fuel bowl is not venting to atmosphere. Note, all of the above have been posted by one or more posters one or more times.

- As a suggestion. For me it helps to print things out and look at them. Puts everything together more than scrolling through the computer screen.

Finally, I see in your latest pictures the float lever has a button which makes contact with needle valve. The contact of the button appears to be proper therefore, that is not a concern for me at this time. Good Luck

Ken
 

Kevin,

Looking closely at his picture - I think there is a button on the float lever - never seen that before. The button and needle contact looks good to me.....do you agree....?

It would be interesting to see what a replacement float looks like.

Ken
 
One thing that went wrong this time is the mechanic put the spring for the float needle in with the weight ball check. There was just the needle and the rod the spring goes on. It doesn't explain though how I rebuilt the carb and it's doing the same thing.

I did the test blowing in the gas intake with the top inverted and the float needle closed. I blew into it as hard as I could and no air passed the needle.

I guess at this point I will take a stab at adjusting the metering rod and put it back together and see what happens.
 
Looks like someone used Teflon tape on the gas fitting.
I have no idea why some people do this but I would check for contamination of tape within the carburetor.
 
(quoted from post at 15:21:48 06/25/17) Looks like someone used Teflon tape on the gas fitting.
I have no idea why some people do this but I would check for contamination of tape within the carburetor.
Click to expand...
Good point. A very few mechanics that know what they're doing actually do this, in order to lubricate the threads, and that's OK as long as care is taken that none gets inside the fuel system.
 
(quoted from post at 10:31:27 06/25/17)
Kevin,

Looking closely at his picture - I think there is a button on the float lever - never seen that before. The button and needle contact looks good to me.....do you agree....?

It would be interesting to see what a replacement float looks like.

Ken
Click to expand...
no, I don't agree. The only "button" I see there is the spring extension, and it still needs to hit the float lever near 90 degrees, as indicated in the pic I modded. A sideways push can still hang the needle up. I DO agree that a new float would be interesting. Just this weekend I have become a member of the school of thought that the float should ALWAYS be replaced. I recently rebuilt my Marvell-Schebler on my Case 611B, found the float looked good and had no gas in either side, put it back in--and it started flooding on me, found gas in both sides. It spent almost 60 years floating in gasoline and never took on a drop until I cleaned it up! I would have liked to have done some digging this morning, nobody to blame but me.
 
I think what you guys are referring to a button on the float is just a metal clip to keep the float from going too far down.

Before trying to adjust the metering rod I went ahead and broke everything down to make sure it was clean and the diaphragm was alright. This is when I found more parts that shouldn't have been there. Underneath the grommet where the metering rod goes in there was a weight-check ball and ball-pump check. I also noticed there is a lot of clearance between the metering rod and the grommet where it goes in. I can't find info as to whether this is correct or not.
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(quoted from post at 16:21:19 06/25/17)
(quoted from post at 10:31:27 06/25/17)
Kevin,

Looking closely at his picture - I think there is a button on the float lever - never seen that before. The button and needle contact looks good to me.....do you agree....?

It would be interesting to see what a replacement float looks like.

Ken
Click to expand...
no, I don't agree. The only "button" I see there is the spring extension, and it still needs to hit the float lever near 90 degrees, as indicated in the pic I modded. A sideways push can still hang the needle up. I DO agree that a new float would be interesting. Just this weekend I have become a member of the school of thought that the float should ALWAYS be replaced. I recently rebuilt my Marvell-Schebler on my Case 611B, found the float looked good and had no gas in either side, put it back in--and it started flooding on me, found gas in both sides. It spent almost 60 years floating in gasoline and never took on a drop until I cleaned it up! I would have liked to have done some digging this morning, nobody to blame but me.
Click to expand...

I looked at the picture again. I agree with you it is the brass spring extension and the contact should be near 90 degrees.

Did you note the clearance between the float arm and the pin. Looks like the pin is undersize...?
 
Yeah, I just chalked that up to wear. I don't think that's the original, but I don't think it's very new either. Just new enough to be made cheap, like all foam floats. Had one of those in a Nissan pickup one time, took on gas, we were in the middle of nowhere, 3-week special order. Put it in the oven at 150 degrees, stunk up the entire house, let it cool down and coated it with 5-minute epoxy. Reinstalled it next day, it was still working a year later even though I told the owner to replace it as soon as possible.
 
I have a float scale and a chart if I could find it. It became useless because I always installed a new float anyways :)... When I order carb parts I order a kit, float and a filter.

The seat has to be TIGHT a screw driver taint gonna do it make a tool that fits both slots insert it in the slots and use a adjustable wrench to nail it tight... I have used flat stock are even ground down a file to fit the slots perfect,,, slipped a adjustable wrench around the flats and nail it tight...

I would not get all worried up about a float that's set deeper in the bowl I doubt you will ever know it...

On most carbs the float needs to be high enoufh so the accelerator pump has a supply yours is in the bottom of the carb :wink: Unless you have the throttle to the floor all the time I doubt it will run out of fuel because of a low float...
 
If I'm understanding your question right the difference between when the float arm makes first contact with the pin and it being fully closed is 1/32". The outside edge of the float travels 1/2". I think the pin is the same size that any that has ever been put on the jeep.
 
I was looking at the jets online for the metering rod. They are available in a lot of different sizes for that carburetor. How do I find out if the parts I have are correct for mine? As best as I can measure the jet diameter is .10 in diameter and the metering rod is .072 in diameter.
 
Sorry, Stephen, I just now saw the pics of the metering rod. Yes, it should fit very loose in the jet. That check ball and the accompanying brass weight go in the hole in the main body between the float chamber and the air horn, check ball first. That's the pressure side of the accelerator pump, it's the valve that prevents the diaphram from sucking air back into the chamber. You should be alright putting the same jet back into the carb, fooling with jet sizes is tricky even for experts. Let's worry about getting your float right, and of course putting all the parts in their correct places. The last guy inside this carb had the Ayatolla saying Mass and the Pope bowing to the holy land 4 times a day.
 
(quoted from post at 19:01:13 06/25/17) If I'm understanding your question right the difference between when the float arm makes first contact with the pin and it being fully closed is 1/32". The outside edge of the float travels 1/2".
Click to expand...
And the weight of the float itself will compress the spring and "fully close" it, correct? What I'm saying is that the float level, measured away from the needle&seat, needs to be set just at contact, not "fully closed", that should keep that float lever just about horizontal like it should be.
 
No, when mounted on the carburetor the float hangs down letting the needle open completely. It's when the bowl fills the float raises up and closes the needle valve. It's sort of the way a toilet tank works.
 
That jet for the metering rod, I don't think I've ever had it out so I don't know who was responsible for the extra parts.

It's a shame about my mechanic. The guy seem to be a life saver for several months. I've been having to work on cars all my life because I can't find a competent mechanic. I've had one shop destroy a motor, another one that set fire to a truck working on the fuel system when it had a stuck valve. I just really don't have the time anymore. There was nearly a year between the time I screwed up the carburetor and had it taken to a mechanic and it's still not fixed.
 
(quoted from post at 19:57:58 06/25/17) No, when mounted on the carburetor the float hangs down letting the needle open completely. It's when the bowl fills the float raises up and closes the needle valve. It's sort of the way a toilet tank works.
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Guess I didn't make myself clear. I mean when the top is off and inverted, as in your pic, the weight of the float will compress the spring inside the needle. Yes, I am well aware of how the float valve works.
 
You were probably clear, I'm just confused. With the top inverted the weight of the float completely cuts off the orifice. I tried to blow air into the intake and I couldn't get any air past the needle. Like I said earlier the mechanic left the spring out of the needle but it's back now.

I wonder if the additional parts under the metering rod could have caused the flooding? Right now this is the only lead I have. I know when I rebuilt the carb I had a spring in the needle so it shouldn't have had a flooding issue from that.
 
I thought I had success. I got the carb put back on the jeep and it started right away and continued to run. Then about 15 seconds later it died and when it did is spewed gas out the bowl vent and also below the bowl at the throttle rod just like it had been doing. The only thing I can think to do is adjust the float to where it is more lean.
 
I'm beginning to make some progress. I adjusted the float like this and the jeep will run and not pour gas out externally. When the float was set near level with the top I think gas in the bowl was coming up to about 1/4" of the top.

It still runs pretty rough though. I need to work on the fuel mixture screw and the idle and fast idle settings. I think if I get these worked out it will be good.
a164090.jpg
 

I know you did the air test to verify the needle valve closed when you had the top off of the carburetor?

With the carburetor fully assembled did you turn the carburetor upside down to verify the needle valve seals off. Sometimes the float hangs up inside the carburetor body preventing it from pushing on the needle. It works fine with only the top and does not work with the carburetor assembled. That was indeed the problem on my brother's YF carburetor.
 
I did the air test and the needle sealed it. I think the gas level just came too close to the top of the carburetor the way it was set making it easy to overflow. Apparently the fuel pump supplies a lot of gas. It didn't take but a split second to fill the carburetor bowl.

I did not blow air into the carb fully assembled. You are correct there isn't very much clearance around the float once inserted in the bowl and I fear it's so close the new float I ordered won't fit at all. Maybe when it comes in I will install the new float and do an air test with it fully assembled. On the other hand if I do manage to get the rest of the bugs worked out before the float comes I probably will leave it alone.

Another question. There is a external tube next to the intake for the bowl. There is a fine screen inside the carb above the bowl to this tube. What is the purpose of this tube? I have had it capped off all these years.
 
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