Cub carb help please

6

69ranger

Well-known member
Hello everyone,

Its been a while since I posted. I am still playing with and using cubs, but just not as much as I would like.
My mowing tractor is a 52 cub, that is in good condition other than it has a warped carburetor top.
I would pay someone to straighten it if possible, as I don't have the fixture. I would be happy to pay them, and and ship it to them, and send a return ship label for return.
Thanks to Bob at the Dewey cub-fest a few years ago for fixing the warped top of another carb, and working his magic. This one has been running perfectly ever since.

The original carb, has been problem for a while, but I was getting by with it, if I used a cork gasket it would seal up until the ethanol fuel would destroy the gasket.
Usually I would get a year or so, but it finally got to the point that it will not seal up.

I tried a couple of china made carbs, and with a bit of adjustment they worked for a while. After a year or so of use, both began to give troubles.
They either wont flow fuel, because of a sticking needle, or they go lean, because of low fuel in the bowl. Even though I figured out what was happening, I am not sure of a path way to fix.
The trouble is with the needle. Its spring loaded, instead of being solid and I think the rubber gets sticky from the ethanol fuel, swelling the tip, and now needle sticks and at best only allows only limited fuel flow.
The tractor will run at idle with the choke partially closed, but nothing else.
I thought maybe I could just change the needle and seat as well as the float out, but it appears the china carb has a different thread on the seat.
The I-H seat will thread in a bit but gets tight before it bottoms out, and I am afraid to force it.
So has anyone installed I-H parts in one of these china carbs?
Sorry for the long post, but I wanted to furnish as much detail as possible, and I probably left something out.

I feel pretty helpless, and I do have decent mechanical skills, and a fair understanding of cub carbs, but I just can't get things to go my way.
Thank you all in advance for your help.
Brad
 
69ranger said:
Hello everyone,

Its been a while since I posted. I am still playing with and using cubs, but just not as much as I would like.
My mowing tractor is a 52 cub, that is in good condition other than it has a warped carburetor top.
I would pay someone to straighten it if possible, as I don't have the fixture. I would be happy to pay them, and and ship it to them, and send a return ship label for return.
Thanks to Bob at the Dewey cub-fest a few years ago for fixing the warped top of another carb, and working his magic. This one has been running perfectly ever since.

The original carb, has been problem for a while, but I was getting by with it, if I used a cork gasket it would seal up until the ethanol fuel would destroy the gasket.
Usually I would get a year or so, but it finally got to the point that it will not seal up.

I tried a couple of china made carbs, and with a bit of adjustment they worked for a while. After a year or so of use, both began to give troubles.
They either wont flow fuel, because of a sticking needle, or they go lean, because of low fuel in the bowl. Even though I figured out what was happening, I am not sure of a path way to fix.
The trouble is with the needle. Its spring loaded, instead of being solid and I think the rubber gets sticky from the ethanol fuel, swelling the tip, and now needle sticks and at best only allows only limited fuel flow.
The tractor will run at idle with the choke partially closed, but nothing else.
I thought maybe I could just change the needle and seat as well as the float out, but it appears the china carb has a different thread on the seat.
The I-H seat will thread in a bit but gets tight before it bottoms out, and I am afraid to force it.
So has anyone installed I-H parts in one of these china carbs?
Sorry for the long post, but I wanted to furnish as much detail as possible, and I probably left something out.

I feel pretty helpless, and I do have decent mechanical skills, and a fair understanding of cub carbs, but I just can't get things to go my way.
Thank you all in advance for your help.
Brad
Click to expand...
If it is an IH carb you can take the brass hex. main jet out of the side of the carb and blow it out. Other than dirt in carb bowl most every carb [cub] problem is dirt in the gas tank plugging the bowl. We used to take the cub tanks off every few years and clean them but now I drain and dry them and tape a small tube to a vacuum .
 
moodnacreek said:
.........but now I drain and dry them and tape a small tube to a vacuum .
Click to expand...
If you are vacuuming a fuel tank, you're asking for trouble unless you purge and/inert the container. Flammable vapors going through a vacuum can create an explosion. After 24 years in a chemical plant dealing with solvents made a believer out of me. JMHO Stan
 
69ranger said:
Hello everyone,

Its been a while since I posted. I am still playing with and using cubs, but just not as much as I would like.
My mowing tractor is a 52 cub, that is in good condition other than it has a warped carburetor top.
I would pay someone to straighten it if possible, as I don't have the fixture. I would be happy to pay them, and and ship it to them, and send a return ship label for return.
Thanks to Bob at the Dewey cub-fest a few years ago for fixing the warped top of another carb, and working his magic. This one has been running perfectly ever since.

The original carb, has been problem for a while, but I was getting by with it, if I used a cork gasket it would seal up until the ethanol fuel would destroy the gasket.
Usually I would get a year or so, but it finally got to the point that it will not seal up.

I tried a couple of china made carbs, and with a bit of adjustment they worked for a while. After a year or so of use, both began to give troubles.
They either wont flow fuel, because of a sticking needle, or they go lean, because of low fuel in the bowl. Even though I figured out what was happening, I am not sure of a path way to fix.
The trouble is with the needle. Its spring loaded, instead of being solid and I think the rubber gets sticky from the ethanol fuel, swelling the tip, and now needle sticks and at best only allows only limited fuel flow.
The tractor will run at idle with the choke partially closed, but nothing else.
I thought maybe I could just change the needle and seat as well as the float out, but it appears the china carb has a different thread on the seat.
The I-H seat will thread in a bit but gets tight before it bottoms out, and I am afraid to force it.
So has anyone installed I-H parts in one of these china carbs?
Sorry for the long post, but I wanted to furnish as much detail as possible, and I probably left something out.

I feel pretty helpless, and I do have decent mechanical skills, and a fair understanding of cub carbs, but I just can't get things to go my way.
Thank you all in advance for your help.
Brad
Click to expand...
There's several posts in the HOW TO FORUM/FUEL on how to make the tool to straighten the IH carb top, including detailed info and pictures on how to make the jig. Here's a link to one by Rudi: https://farmallcub.com/community/threads/how-to-make-an-updraft-carb-straightening-jig.24466/ I've not done this myself but watched Bob McCarty and Don McCombs many times at a Cubfest. Good luck, Stan
 
staninlowerAL said:
If you are vacuuming a fuel tank, you're asking for trouble unless you purge and/inert the container. Flammable vapors going through a vacuum can create an explosion. After 24 years in a chemical plant dealing with solvents made a believer out of me. JMHO Stan
Click to expand...
That s good advise but in my post I said I dry the tank after draining.
 
moodnacreek said:
That s good advise but in my post I said I dry the tank after draining.
Click to expand...
That's a good step but just to be clear, the only way to determine if there's dangerous conditions is to test the LEL. It may look/feel/seem dry but still have unsafe conditions. In industry settings we used a meter to test and measure the atmosphere in the container. Another way to do it is to introduce a non flammable atmosphere with a non-flammable gas (carbon monoxide) like exhaust from a running engine. That will create an condition inside the container without oxygen and be much safer.
 
Thank you all for your help.
Hopefully I didn't create confusion, as that was not my intent. My tank is clean as a whistle, and thankfully has never been rusty.
I did have it off to change the belts, a year or so ago, and I flushed it out at that time, as well as changed the sediment bowl gasket and screen.

The trouble began with the original carb being warped and not holding a gasket tight enough to seal properly.
As a stop gap measure I bought a China carb, and after adjust the float installed it. Big mistake by the way, as they seem to take a few liberties with the original design. Different threads on the inlet, and seat, and their rubber needle swells over time and restricts flow, causing a lean condition.

I appreciate the link to the straightening jig print. I did not realize these could be made out of 1/4 inch material, and I have that laying around.
So I will attempt to make one of these and perhaps straighten it to the point that it seals up.
This would be the hope, as I think the original is a better go, as parts are available.

Thank you all again,
Brad
 
staninlowerAL said:
That's a good step but just to be clear, the only way to determine if there's dangerous conditions is to test the LEL. It may look/feel/seem dry but still have unsafe conditions. In industry settings we used a meter to test and measure the atmosphere in the container. Another way to do it is to introduce a non flammable atmosphere with a non-flammable gas (carbon monoxide) like exhaust from a running engine. That will create an condition inside the container without oxygen and be much safer.
Click to expand...
Guess I better not post anything about welding gas tanks or wheels.
 
Friend of my son Aron
Welding Accident

He wasn't welding near the fuel tank, but there were enough fumes coming out of the tank that the welding sparks ignited the fumes back into the tank.

Don't mess around with fuel tanks!
 
Thank you to Bob for the call yesterday, and the offer to help. I truly appreciate you Bob, as well as all the rest of you fine folks on this forum.
After Bob and I talked I decided to send him my original carb for straightening and for his magic touch.
I am so pleased to be able to save the original carb off of this tractor.
Thanks again everyone!
Brad
 
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