VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 Carb issues 28 brass bowl carb

Hi
Was going to go into a long chat about the carb not working right on the car I recently picked up but it appears the carb is missing the pump portion of the carb.
So does anybody have a rebuilt brass bowl Carter RAKX-O for sale ?
Thanks in advance

The 28 Carb does not have a pump??????

Haha ok the instructions showed a pump on the side and mine seems to have a plugged hole on the side so I thought it was missing something.
Mine seems to want to keep overfilling the bowl
I checked the float it’s not taking on fuel
If I leave the bowl off and run the float up and down with my fingers it seems to work fine
But once the bowl goes on it will overfill again
I tried repositioning the bowl carefully to make sure it was not catching the side of the float or something but same thing.
I set the height of the float a little lower but still no luck.
What I’m I missing ?
Thanks

Look on the side of your carb and make sure you have the correct carb for the 1928.

There is the posibility that your float has sunk. Place it in a pan of warm water and see if you get any bubbles. Also, just shake it and see if you hear fuel sloshing around.

Floats can be repaired or new ones are available.

You may also consider having your carb rebuilt.

Check the vent for the fuel bowl on the top side of the body just above where the brass bowl seats. If that vent is plugged the carburetor will overflow fuel.

Hi thanks guys yea I shook the float before it seems fine.
I will check the vent that could be a possibility I will check that out tomorrow

Side of the carb check ......for the 1928 .......will it have the year cast on the side ? It has the RAKX-O , but I will check for other casting marks.

Thanks guys

If it has raised "RAKX-0" on the casting the body at least is for a '28 Chevy. That does not insure that all the other parts are correct. Many things could have happened in the 90+ years since it was made.

Do you still have the gravity feed fuel supply, or has someone added an electric fuel pump?

No way will the RAKX-0 carb take more than about 1 pound pressure, and the inline dial type pressure regulators only have value if you have a rabbit issue in your garden, and a strong arm.

Jon.

Hi thanks
I am just putting the all stock fuel system back in
Right now I’m just using a small jug it holds about a 1/2 gallon of fuel and is gravity feeding, I wonder if when it’s full it has to much pressure ? Would make sense with it working a bit yesterday, then overfilling the bowl could have been happening when I was topping up the small tank , maybe it holds just enough fuel to apply to much pressure gravity wise.
I am not familiar with the amount the original tank holds but with the float and everything in the original tank , this one probably holds more.
Thanks again

The distance between the top of the fuel level in the tank and float level in the carburetor determines the pressure. That generally does not change much until the tank runs out of fuel and only what is in the small diameter line counts.

Ok well I have the tank currently hanging high on the firewall so the fuel level in it is a lot higher the top of fuel level in the bowl

Looking at a Stewart tank, I would guesstamate less then a Qt of fuel in it (maybe more in the pint range). The Stewart instructions say that the bottom of the tank should be in the ball park of not less then 3 inches above the top of the fuel bowl. The fuel bowl could be over filling because the shut off valve is not sealing. Could be dirt or bad needle and seat.

Mine leaked through the fiber washer between the carbutettor body and the removable seat that the needle goes into.
That caused the bowl to overflow. To find it I submerged the carb in water with the float intact and blew air through the fuel line.

Hi
Thanks I will have a look in at those areas to, didn’t get time yesterday, but the next day or two I will check it out again.
Thanks

Hi There,
these carbs are needle seats are designed for vacuum tank operation, if electric fuel pump is used the needle valve can't handle the extra pressure and will not seat

That is why you install a regulator set for 1 to 1-1/2 pounds.

A pressure regulator don't work either. Just can't set it that low. Go with the vacuum tank as designed. If it don't work, get it restored so it does work.

You might take a look at the fuel valve.

There are several possible types that may have been used in the last 90 + years, but the valve itself will be:

(1) metal
(2) metal with a synthetic tip
(3) plastic

If metal, inspect for a groove where the needle contacts the seat. If a groove is present, the needle AND seat should be replaced. A TEMPORARY fix is to chuck the needle in a lathe with a taper attachment and grinding attachment, and remove the groove. This will shorten the overall length of the needle, and require adjustment of the float. Adjust the float by changing the thickness of the gasket underneath the seat.

If metal with a synthetic tip, inspect for damage (cuts, etc.) to the tip. If damaged, replace the valve AND seat.

If plastic, probably better to just replace it. Plastic needles were an early experiment by Carter to solve the issues caused by metal valves. The experiment did not work, and Carter only offered the plastic valves for a couple of years.

One general comment: NEVER (and I detest the use of the word never) bend the tab of the float to adjust it. Changing the thickness of the gasket under the seat is the way to adjust the float, especially on the 1928. The 1928 float is one-year only. You don't even want to think about trying to replace it if bending the 90 year old brass tab resulting in breakage. As far as new floats are concerned, I am unaware of any US-produced reproductions, and the solder used on those from a far-away land is NOT compatible with modern gasoline (they often fail in as little as 3 months). So best to treat the original with TLC.

Jon.

Thanks so much for the reply
Just got back onto work on the old girl
Installed a rebuilt Vac tank on it, looped the line kind of done under the carb and up to it .
Tank seems to be working fuel to the carb, but again to much fuel, took apart re cleaned , tested things well apart, float is not taking on fuel .
Can’t blow through it now , upside down and unseat the needle , could before noticed the seat was not sealing installed old seat and it sealed, new seat had a little protrusion pass the threads old seat not made that way, thought maybe it was bottoming out before the gasket could seal.
Seems I can get it working for a bit then same issue, or motor will run for a bit and then die.
Seems like not enough fuel at times and overflowing the bowl the next minute.
About three of us picking away at this with several,years of experience but not with this set up and we are struggling one is a pretty seasoned model t guy........maybe the ford guys the problem!! Haha just kidding
Any help appreciated And maybe a carb for sale. Suppose to have this thing ready for some of the daughters wedding pictures here in August, currently not looking to good
Thanks
.

I suggest you not only blow out and squirt carburetor cleaner but also use some abrasion where you can. A twisted paper towel wetted with carburetor cleaner rotated in the seat and rubbed against the sides of the needle will clean most of them. Best I found is Berryman's B-12. WalMart brand okay. Some of the others are worthless. I have rebuilt over 200 '28 Chevy carburetors. Good thorough cleaning is critical. Also need to be sure the fuel bowl vent is clear. If not gas will overflow.

Great. Thanks I appreciate it, I will try that Friday then thank you
I’ve tuned 2500 hp engine, can’t make a 1 barrel updraft work haha
Thanks I will keep you posted I did check the vent I will dble check that to

Hi
Back at it the breather hole seemed fine from the outside but not the inside plugged for sure, but seems like it is plugged with a copper plug ? Is that normal
I thought I should be able to poke a pins or something through ?
And I am now giving it a another more aggressive cleaning.
Thanks for your help

The bowl vent must be open. If not the needle/seat will not work properly and the bowl will be overfilled with gasoline. I have proven that way too many times.

I ended up drilling it out so it is breathing now
Ended up with the vac line to the vac tank sucking fuel in to the manifold , so I figured it had to be a float issue in the vac tank, so I pulled it apart and compared it to another old one I have , and it appears it is missing a small arm that extends forward and pushes the needles closed when the float goes up.
Anyway put the other one on and ssssooooo happy to say it is now sounding and running very good even drove around the yard.
That sooooo much people and thanks Chipper. Cleaning and cleaning the carb and for whatever reason having to drill out the breather hole, and it now sounds super., might make wedding pictures yet, still fixing lots of other things and cleaning up the bodywork .
But finally a good runner so awesome !!!!!!!

Glad to be able to help.

In the thousands of miles I and other VCCA members drove on tours most everything that can happen has. After a while you learn what can go wrong and how to fix them. There is nothing better than driving on a VCCA tour.

Also having rebuilt nearly 1000 early Chevrolet carburetors and nearly 100 vacuum tanks helps to understand those units as well.