63 flooding

[MeAndTK]

I’m a newbie, having owned my 63 only a year.
It began flooding recently. It wasn’t gradual, but just began happening one day
I wondered about the gas I’d bought, so I added some B12 to the gas. It had no effect.
Where should I begin?

Thx

Jason

[Glen]

Hi,
It sounds like dirt may have gotten in the needle and seat in the carburetor, and is holding the needle open, so it is leaking gas out.
I would take the carb apart, and the float out, and clean the needle and down inside the seat.
Be careful and don't scratch the end of the needle, or down in the seat.

A 1963 Cub originally came with an IH carburetor, I don't know if your Cub still has it, the Zenith carb was used later on Cubs, and some have been changed to those. I would identify which brand you have first.
Below are pics, the 1st pic shows an IH style carb.

Here is some info for cleaning and repairing the IH carburetor, if you need it.
You might not need all the info, but it's important to set the float level right.

Before taking the carb apart, clean the outside of it, to keep dirt out of the carb.
When taking it apart, pull the 2 halves of the carb straight apart several inches, there is a small idle tube that screws into the top half of the carb, and sticks down into the bottom half of the carb, it can break if you twist it, or don't pull the 2 halves straight apart.

Use carb cleaner, or solvent to clean inside the carb.
All the passages need to be open and clean.
Blow them out with compressed air, and be sure they are open. Use your safety goggles when using the air.
Remove the main jet, the 6 sided brass colored part low on the side of the carb, and run a small wire in the hole in the end of it, to be sure it is open, and then wash the jet.
Tighten it gently, it can break. It should have a fiber washer under the head, to seal it, sometimes if the washer is old, it won't seal if you reuse it.

The needle and seat could have dirt in it, making it not seal. Remove the float and the needle and check for dirt, clean the needle and seat.
Check the float, it should look in good condition, not collapsed or corroded.
Shake it gently while it is off, it has to be dry inside, no gas inside it.
If it is good, it can be used again.
Assemble the needle and float again.

The tab on the float arm has to face up.
Sometimes the float is upside down.
Put it in the right way, if it is upside down.

It is important that the float level and float drop be set exactly.
People on here have said that their carb wouldn't work right until they set the float level exactly.

Below is a page from the Cub and LoBoy service manual showing setting the float height.
The IH carburetor is in the upper pics on the page, the Zenith carb in the lower pics.
To set the float level, turn the top half of the carb upside down, like the pic of the Zenith carb, in the lower right of the page.
Don't use the float level specs shown for the Zenith carb, for an IH carb, they are different.
The gasket between the halves has to be off, when measuring the float level of the IH carb.

http://www.farmallcub.info/manuals/gss- ... 002-09.jpg

Bob McCarty converted the measurements to use a dial caliper, it is easier.
The float level is 1.4"
The float drop is 1.6"

Bend the float arm between the float and where the needle touches it, to change the float height.

Turn the top half right side up to set the float drop.
Bend the tab in or out to change the float drop.

The needle and seat could be wornout from years of use, and don't seal, then the carb can drip on the ground when the Cub is sitting.
I have seen them that were wornout, they dripped, and then it quit dripping after putting in new ones.
The IH carb has a small screen where the gas line attaches to the carb, be sure it is clean.
Tighten everything on the carb gently, the IH carb is soft metal, and threads can strip.
The carb top can warp if the screws are tightened too much.
You could check the gasket surface of the top when it is off using a straight edge.
TM Tractor, at the bottom of the page, has new carb parts.

Below are pages from the Cub parts manual showing the IH carb.
The main jet is number 28 in the pic.

http://www.farmallcub.info/manuals/cub_ ... 012-12.jpg

http://www.farmallcub.info/manuals/cub_ ... 012-13.jpg

Cubs have a manual choke, you have to use the right amount of choke when the engine is cold, until it warms up, so it runs good.

The 1st pic below is an IH style carb, it is a replacement carb, I think, but looks like the IH carb.
The 2nd pic is an IH carb float from TM Tractor, showing the tab for the float drop.
The 3rd pic shows cleaning the main jet.

[Glen]

The gas strainer under the gas tank needs cleaning if it is dirty inside it.
The strainer is supposed to have a fine screen above the bowl gasket, to keep dirt out of the carb.

Below is a page from the 1955 Cub operator's manual, showing cleaning the gas strainer.

http://farmallcub.com/rudi_cub/www.clea ... e%2032.jpg

It is easier to get to the strainer if you move the Touch Control arms to the rear, or down position before shutting off the gas.
If the gasket is old, it sometimes won't seal if you try to reuse it.

TM Tractor at the bottom of the page has a new gasket and screen, if you need them.
Below are the listings.

http://www.tmtractor.com/new/fl/426fp.htm

http://www.tmtractor.com/new/fl/235fp.htm

[MeAndTK]

Thanks
I’ll be a few days until getting around to it.
It is IH carb.

I’m thinking I got dirty gas. My mowers aren’t running as smoothly as they should be either.

[NJ Farmer]

The float might be sunk (hole in it). After you take it apart shake the float….if you hear fluid in it it’s sunk or shot….need a new float.
Also check the needle and seat for possible debris under it.

NJ farmer

[MeAndTK]

Before I went tearing into it, I decided to spray it with carb cleaner and see what happened. It was very dirty. I let it dry, added fresh fuel and Berryman’s B12, and it runs much better. My mowers were running ragged, too. I think I got bad gas and some trash got into the carb.
I worked it in my garden for about 30 minutes with no problem.

Thanks for the advice. I’ll keep it on hand, because I’ll probably need it in the future.