Holley Double Pumper Question(s)

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It might be on the fast idle cam?

You don't need that bracket as long as your throttle cable is connected to the hole under the big hole, which provides the correct ratio.
 
remytherat said:
It might be on the fast idle cam?

You don't need that bracket as long as your throttle cable is connected to the hole under the big hole, which provides the correct ratio.
Click to expand...
Thanks your advice got me looking at the choke. It was the choke and it was full on causing this. I feel pretty stupid. Oh well, live and learn. Thank you for the input!
 
340inabbody said:
I saw that as well. Apparently there are several carbs of this type. The 777-7 is not a four corner set up however the 777-C is….
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Good guess but not correct.

-7 is the revision
C is the dichromate finish
The number underneath is the date code.
For example, from the 2018 catalog.
1715005848502.png


So either the current revision changed meter blocks etc, or the photo is wrong because the marketing staff is clueless.
My bet is the latter :(

The website info says its an dichromated aluminum body carb with straight boosters. I'm not aware of dichromate finish for aluminum casting as those are usually anodized. Second, the website photo shows downleg boosters. Third there is no mention of four corner idle even though the website photo shows it.
 
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Find yourself a used copy of Holley Carburetors and Manifolds by Bill Fisher and Mike Urich, any edition.
You're buying for a good intro into how carbs work and the diagrams, not the marketing content.
Alternatively for less, the smaller Holley Carburetor Handbook, Models 4150 & 4160, Selection, Tuning & Repair
By Mike Urich
 
Mattax said:
Good guess but not correct.

-7 is the revision
C is the dichromate finish
The number underneath is the date code.
For example, from the 2018 catalog.
View attachment 1716246254

So either the current revision changed meter blocks etc, or the photo is wrong because the marketing staff is clueless.
My bet is the latter :(

The website info says its an dichromated aluminum body carb with straight boosters. I'm not aware of dichromate finish for aluminum casting as those are usually anodized. Second, the website photo shows downleg boosters. Third there is no mention of four corner idle even though the website photo shows it.
Click to expand...
Fair enough it was an assumption on my part and I was wrong.
When probing the hole with a needle it was blocked off. So I think it’s not a marketing issue. I believe this unit is not a 4 corner unit.
Mattax said:
Find yourself a used copy of Holley Carburetors and Manifolds by Bill Fisher and Mike Urich, any edition.
You're buying for a good intro into how carbs work and the diagrams, not the marketing content.
Alternatively for less, the smaller Holley Carburetor Handbook, Models 4150 & 4160, Selection, Tuning & Repair
By Mike Urich
Click to expand...
Thanks
 
It’s right there in the text of the picture Mattax posted. “Two corner idle”
D7768099-5257-4810-9E13-A44DE8C194DC.png
 
340inabbody said:
When probing the hole with a needle it was blocked off. So I think it’s not a marketing issue. I believe this unit is not a 4 corner unit.
Click to expand...
You are correct, it is not a four corner idle carb. Always good to check in case a previous owner swapped blocks and drilled the body to convert it.
But the images on Holley's website show a four corner idle carb - that's Holley's mistake. Their circa 2018 catalog had it correctly described and pictured.

On the top of the metering block are additional numbers. On the older Holleys, often the carb list number will be stamped (eg 4777) other wise it will be the block number. Just another clue when figuring out what you have.
 
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