Rebuilding carburetors at home

[493 Mike]

For corroded float bowls (aluminum and cast iron-used to do a lot of tractor carbs) plug the jets/orifices and bead blast the bowls.
Mike

 

[Photon440]

One carburetor I had on the Duster developed a blocked internal passage for the accelerator pump. The ethanol here is okay if you run the engine on a regular basis but fuel sitting inside awhile seems to lead to crud buildup.
How do you adequately clean a small passage? Nobody makes "pipe cleaners" that small.

Some of the tools used to clean paint guns will also work on carbs.
www.amazon.com/DESIN-Carburetor-Cleaner-Airbrush-Cleaning/dp/B09V2W31LR/ref=sr_1_1_sspa?keywords=carburetor+jet+cleaner&qid=1704564218&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&psc=1

 

[Gus chiggins]

One carburetor I had on the Duster developed a blocked internal passage for the accelerator pump. The ethanol here is okay if you run the engine on a regular basis but fuel sitting inside awhile seems to lead to crud buildup.
How do you adequately clean a small passage? Nobody makes "pipe cleaners" that small.

Mig welding tip cleaners, they come in small case with various sizes, or maybe a wire pulled from a wire brush

 

[Kern Dog]

I forgot to ask....
What about the solvent to soak carburetors in? Years ago, you'd buy one of those 5 gallon cans of that Berryman brand "Carb-Dip" or something like it. I had a can but once when I ran the weed eater, a small piece of gravel got smacked by the trimmer line and it punched a small hole near the bottom and it leaked out.

EDIT....Here it is.
Wow...the price really went up with this stuff!

 

[F4R/T]

Geez that’s crazy on the price!

 

[493 Mike]

I forgot to ask....
What about the solvent to soak carburetors in? Years ago, you'd buy one of those 5 gallon cans of that Berryman brand "Carb-Dip" or something like it. I had a can but once when I ran the weed eater, a small piece of gravel got smacked by the trimmer line and it punched a small hole near the bottom and it leaked out.

EDIT....Here it is.
Wow...the price really went up with this stuff!

View attachment 1651726

I bought a pail about 5 years ago ($125.00) and decided with the low volume of carb rebuilds I was doing now days, I had to add a chemical surcharge to my billing.
Mike

 

[WileE]

While using chemical cleaners and/or compressed air, ALWAYS wear eye protection.

 

[AR67GTX]

The Berryman stuff is not as potent as it used to be. It’s been neutered by EPA. That’s why I bought an ultrasonic cleaner.

 

[493 Mike]

The Berryman stuff is not as potent as it used to be. It’s been neutered by EPA. That’s why I bought an ultrasonic cleaner.

Oh ya, they took out the acid (probably replaced it with water). That's why it takes 24 instead of 1/2 hours to soak! I rinse them in my solvent tank and brush the pieces as I rinse.
Mike

 

[RemCharger]

The one bbl's are a little simpler to build

 

[Kern Dog]

I see that 96 ounce jugs are commonly available but how the heck is a carburetor main body going to fit in a container smaller than a 1 gallon can?
I know that I don't need a full 5 gallons but I don't see an in between option.

 

[sam dupont]

I see that 96 ounce jugs are commonly available but how the heck is a carburetor main body going to fit in a container smaller than a 1 gallon can?
I know that I don't need a full 5 gallons but I don't see an in between option.

something like this might be handy

LIFE LATCH® NEW GENERATION 2.5 GALLON PLASTIC PAIL WITH RED SCREW TOP LID – WHITE

This Life Latch® New Generation 2.5 gallon plastic container is a quick access bucket with screw on lid that is red, has a built-in plastic handle for convenient carrying, is UN rated, and is child resistant and senior friendly.

ebkcontainers.com

 

[Kern Dog]

The end of the description "Senior Friendly" is something we all may need at some point!
That is worth considering. Thank you, Sam.

 

[Photon440]

The Berryman stuff is not as potent as it used to be. It’s been neutered by EPA. That’s why I bought an ultrasonic cleaner.

From the Berryman website:

Since the inception of Professional Chem-Dip Carburetor and Parts Cleaner (current part #0905) in the 1950s, the primary ingredients have been cresylic acid, methylene chloride, and sodium dichromate. Cosolvents and additives have changed a little as government regulations and chemical shortages have both affected what additional components we’ve been able to use. However, it is fair to say that the current formula is still substantially similar, being comprised of aromatic and chlorinated hydrocarbons.

 

[Kern Dog]

I did get a couple cans of this today.

I might get a third and one of those plastic buckets listed above.

 

[ckessel]

As others have said, obviously clean, clean, clean.

One of the problems with Holleys are that that they warp. Then you can rebuild them all you want and they don't work worth s**t.

Once you get the main body separated check it for straightness. I'll almost bet that the body, behind the metering blocks, is warped (this is because people tighten the heck out of the fuel bowl screws). If it is warped, file or sand it until it's flat. Check also where the body connects to the throttle plate, although this area is much less problematic.

Here are a couple of pictures to explain what I mean.

This is near the beginning of filing. Note the dark areas that have not been touched, and conversely, the edges that are high and therefore have been filed.
View attachment 1585868

Here is another carb near completion. You can still see low spots.
View attachment 1585867

Bottom line is be sure the body is flat! If it is not, then you may end up with internal leaks that will make the carb impossible to tune!

I learned about main bodies being warped back in the 70's. For sure they cause poor running and no matter what you try, just can't get them to run right due to internal leaks. When I first flattened them out, I used a single cut file. Later on I had an aluminum block made that would just fit on the bottom after you removed the throttle plate. I would put 80 grit wet or dry paper on, lube with water and slowly sand away, making sure to not rock it. When it was close, I would swap to 180 or so grit. Same on the metering block surfaces. When I was doing Holley's for side money, after cleaning in dip, I would sand the bodies. There is also a passage on the throttle plate that you could enlarge with a certain size bit, drill down a certain depth, put a small Phillips screwdriver in the passage, whack it a couple of times to score it and use one of the ball bearings supplied in the kit and put it in the hole before assembling. This was a no buck power valve block off for protecting the pv when you get a sneeze back or cough through the carb which will blow the valve diaphragm.

 

[Kern Dog]

I am 1 for 2 with carburetors lately.
The one from this car:

Is the basic Holley #1850, the 600 cfm 4 barrel vacuum secondary. It ran great but had a leak around the accelerator pump. I replaced the diaphragm and it seems fine again. Great idle, smooth operation too.
The second carburetor is still giving me trouble. It is the same model, just a few years newer.

At first, I was dealing with the carburetor running but flooding over. I first considered that the fuel pump I had was putting out too much pressure. I had a thread about it here:

Can a stock fuel pump put out TOO much pressure?

I had this Holley and a rebuilt ThermoQuad that both flooded over when idling. I tried the carburetor from the black Dart and suddenly, it ran much better. I pulled this Holley and adjusted the floats, replaced a few gaskets and the power valve then reinstalled it.
It didn't flood over but didn't want to idle. I had to crank the throttle open 1/3 the way to keep it running so.....I pulled it apart and soaked everything for just over a day. I ran carb cleaner and compressed air through it and screwed it back together.
Now it will run but still not great. It smokes a little black and idles rougher. I had to screw the curb idle screw in to get it to idle on it's own.
There was nothing obviously dirty or damaged inside. I don't know what could be wrong with it. I do have some spare metering blocks, jets, other parts to swap in but I don't know what else to do with it.

 

[493 Mike]

What if you rigged up a gravity feed to the carb, no pump at all. That would rule out the pressure issue.
Mike

 

[HawkRod]

...I don't know what else to do with it.

See my post #18 in this thread.

 

[Kern Dog]

As others have said, obviously clean, clean, clean.

One of the problems with Holleys are that that they warp. Then you can rebuild them all you want and they don't work worth s**t.

Once you get the main body separated check it for straightness. I'll almost bet that the body, behind the metering blocks, is warped (this is because people tighten the heck out of the fuel bowl screws). If it is warped, file or sand it until it's flat. Check also where the body connects to the throttle plate, although this area is much less problematic.

Here are a couple of pictures to explain what I mean.

This is near the beginning of filing. Note the dark areas that have not been touched, and conversely, the edges that are high and therefore have been filed.
View attachment 1585868

Here is another carb near completion. You can still see low spots.
View attachment 1585867

Bottom line is be sure the body is flat! If it is not, then you may end up with internal leaks that will make the carb impossible to tune!

Excellent point. Thank you.
There are no vacuum leaks, no fuel leaks but it runs rough and a bit rich too.