Farmall Cub

Are idle tubes available?
I have three carburators soaking, one came off a cub that has ran, one came off a cub that runs very good and the other I am not sure where it came from.
When taking them apart, I had my little brother to observe, because of the idle tube fragility [ thanks cub club posters ].
My brothers first question " where is that tube that is so precious". His second question " how did it run for a few minutes.

So my question are they absolutely required?

Thanks:
Cottonpicker

Idle tubes are available. Last one I bought was about $30. They have a 4-48 thread if you snapped one off.

The IH engineers included the idle tube in the carburetor design for a reason. Will it run with the majority of it missing? Maybe. Will it run properly with the orifice portion of the idle tube missing? Not likely. Will it run best with an intact idle tube. Most definitely. If yours is missing, I'd carefully remove what is remaining and replace it. You can get one from CaseIH for about $30. Or you can get one from McDonald Carb & Ignition for $8. http://www.mcdonaldcarb.com

I checked out the link but they did not have the idle tube listed under IH carb parts. If you search for "cub idle tube" you will find it for $14.95- still a great deal.

Steiner also has them for $14.95.