M Carb Dumb Question Time

OK. Dumb question time. Y'all helped me with adjusting the valves. I'm hoping you can help me again.

I've rebuilt 4bbl carbs before, and I ordered a carb rebuild kit from YT Mag's parts page. I don't foresee problems actually rebuilding the carb for my Farmall M. However, I do see issues with adjusting the carb and governor after reinstallation.

There's the idle adjust, the power adjust and the governor linkage. I assume I start with the idle. With a 4bbl, I adjust for highest vacuum. How do I properly set the idle on a Farmall M? Is there a port where I can tap off vacuum?

Then, I assume I adjust the governor, so that idle is the right RPM at the bottom notch on the throttle handle. Is that right? Or do I adjust the governor so that max RPM is at the highest notch on the throttle handle?

I assume I have to have a little back and forth to get both the idle and the governor set right.

Then, there is the power setting... I don't even know which screw is the power setting and which is the idle setting. And how do I set the power screw properly?

Yes, I do have an IT manual for the M, but this web site generally has practical ways to do things. You folk out there are [b:654c4848f0][u:654c4848f0]GREAT[/u:654c4848f0]![/b:654c4848f0] So, I rely on y'all more than the writings of one person.

You are making a mountain out of a molehill.
The low speed idle mixture screw is turned in until it lightly seats, and then you turn it exactly 1 1/2 turns out.
The high speed idle, or load screw, is turned in until it lightly seats, and then exactly 3 turns out.
The idle speed adjustment screw is turned in untill it just touches the throttle rod cam, and then maybe an additional 1/8 to 1/4 of a turn.

Kewl! So, which screw is which?

If you have rebuilt 4 BBL automotive carbs, you should be able to figure it out. I don't want to spoil all your fun.

Is that a up draft quadrajet?

Dan,
If all that you work on is the carburetor, the governor should not need to be changed or adjusted until after setting the carb.
Top screw - Idle stop. It keeps the butterfly from closing too far.
Middle screw that points toward the radiator - Idle mixture. Opening up this screw leans the mixture. Set for highest rpm without making black smoke (too rich).
Bottom screw - Load adjustment.

Set them in the order you just read them.
Put the throttle hand lever as you want it. There's no right or wrong, it is your preference. I had to set the operating range of the lever up on my '51H because of worn teeth on the plate.

Hee Hee! I like that! Reminds me about the early F4U Corsair fighter aircraft. They had an updraft carburetor and a 2800cid engine. If you primed the engine a little too much, you'd get a puddle of gasoline on the deck right beneath the engine. Then, if you had a little bit of backfire, you were in trouble. So, it was standard Navy practice to have someone standing by with a fire extinguisher when these babies were started. Later models had a downdraft carb, and the problem went away.

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[b:654c4848f0][u:654c4848f0]**THANK YOU**[/u:654c4848f0]![/b:654c4848f0]

AMEN! There is a lot of knowledge on this site and a lot of people willing to share it.