72 Olds daily driver best MPG carb?

[Seff]

Gotcha. I received my book a rebuild kit yesterday, put the carb together today, will see how it runs tomorrow. I found the APT screw, but not where it should be adjustable from the outside. 1977 Olds carb.

[Seff]

To follow up: I drilled and tapped a hole for the APT adjustment, and did the initial refurb with all new parts. Currently having the following problems:

It takes a long time for the choke coil to heat up and get off the fast idle steps.
When it finally comes off the fast idle cam, the idle surges, fast for one second, slow for the next, and so on.
The car barely has any power.

Due to the rough idling, I've yet to adjust the APT, so it's just bottomed out, since I wasn't the one that took it out. Would that cause these problems (or some of them)?

[Cliff Ruggles]

I'm just a bit confused.  Part number 17057253 has a removable plug over the APT adjustment, no drilling should have been required to remove it.

The choke is fully adjustable.  It should be set with the engine dead cold, till where it just closes the choke flap when the throttle is depressed.

Set the choke pull-off to unload the choke to the correct angle at initial start-up.

Set the APT screw to 3.5 turns up from seated for initial testing.....Cliff

[Seff]

The air horn had no plug and no other provisions for the later style APT. There's a brass cap over the area of the '75 type APT, could the air horn have been moved to the '77 body? The other '77 carb I had had a plug, but at least the hole was there. The only other difference between the two air horns is that the choke pulloff vacuum attached to the air horn WITH the plug, while it attached to the main body on the one without the plug (but that I've drilled).

So not the good old 'hold choke plate open until pressure is felt, then set to index'?

Gotcha.

Again, gotcha. Hopefully I can do tip-in from there.

[Cliff Ruggles]

Yes, someone installed a different airhorn.  Hopefully it was from an Old's carburetor, or it may not work quite right.....Cliff

[Seff]

Yeah, I hope so too. I'll take a picture of it. Certainly an M4M-type, and the air tube and so forth is identical to the other one. The reason I don't use the one with the plug is that it's rather beaten up.

[Seff]