IH Carburetor Revisited

[Donny M]

Got fooling around this morning with a couple of IH carbs. Here's some things I found but haven't figured out yet.

Three completely different discharge tubes:


You can see that all three are quite different, but wait there's more, here's the ends:

The two on the left are the same dia. (.125") but one end is closed. The one on the right has a different dia. (.140").

And then there's the main jets:

These both have the same dia. orifice (.036") but the one on the left has a counter bore that is .250" deep.
The parts manual lists two different part numbers for the discharge tubes and four different part numbers for the main jet.
Makes one wonder.

Mr GW is doing some research in this matter, hope I didn't cloud the issue

[George Willer]

Mr GW is doing some research in this matter, hope I didn't cloud the issue

I've run into the same snag, Donny. If there's any sense to be made of the differences, I can't find it. It's fairly apparent that the differences aren't very important, but who really knows?

The important detail is that they seem to run well regardless of which nozzle they have.

[Bigdog]

I think it's highly possible that some parts / pieces were contracted out and were spec'ed to perform at specific parameters. Some changes could have been made by manufacturers and supplied under the same part number to IH as long as the specified parameters were still met.

[Buzzard Wing]

That is strange!

I thought I had pictures of everything but none of the details on the main jet. Will be interesting to see what is in the two carbs I have in the garage look like.

[allenlook]

I have two more in the barn that look different than those you showed, so that's at least 5 variations...

[Donny M]

I have two more in the barn that look different than those you showed, so that's at least 5 variations...

It would be interesting to see them.

[George Willer]

Donny,

The farther we go, the more complicated it becomes. You mentioned a notch and wondering if it were original... Here's proof that it is. It would be possible to create the notch in the field, but adding the metal to make the bridge would be unlikely. I have 2 bowls on the bench right now with the notch and 3 without.

A little while ago I thought I could solve the mysteries of these simple little carburetors. I'm not as confident now.

[Donny M]

Mr. GW,

That's exactly what I was speaking of last night on the chat. I figured it to be original and was wondering what the carb part number would be. With that info maybe we could possibly figure out where the different discharge tubes/main jets should end up.

By the way, I didn't fall asleep last night at the computer, I was putting a 1/4-28 heli-coil in a couple of carbs. Kind of funny, when I returned to the computer I just started typing as if someone was there. Seems as if everyone else turned out their lights
One other thing, when you put a 1/4-28 heli-coil in for the main jet, the idle tube must be shortened. This hasn't effected the performance of the carb so far today.

[Bad Boy]

On Jan 30 2006, there were different parts in the IH carburetor, what was the final out come and does this make any differents in performance from one carb to the other?
Bad Boy

[cowboy]

I knew I should have had my carb apart and waiting for Carl when he visited I have been putting off doing my carb agin. I will try to take it apart this week and post all the part # and style of carb. It is a '64 I think it is all original. And try to find the guy I got it from and see if his grandpa got it new. Looks like the only thing ever on it was the mower as cork is in all the other mounting points.

Billy