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Old 07-02-2019, 07:11 AM
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Default Another Center Carb Choke Question

What would cause the choke to go from 'fast idle' when started, to drop past 2 positions on the cam, and to go directly to the 'normal idle' lowest position after a small bleep of the accelerator within 10-15 seconds after starting?
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Old 07-03-2019, 09:21 AM
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Anyone have a suggestion regarding this issue?
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Old 07-03-2019, 10:33 AM
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Mine will drop from fast idle to normal idle with any touch of the accelerator. I assumed that was normal operation.
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Old 07-03-2019, 12:27 PM
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The fast idle should drop from full choke to midway between when you first tap the throttle. After a few minutes, tapping again will drop to normal idle. This is controlled by the setting of the choke dial on the center carb. Turn the dial counterclockwise (richer) about 1/8" on the OD and you'll notice a difference.

But, if you tap the pedal as it is now and the engine doesn't stop, I'd leave it as is.
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Old 07-03-2019, 02:15 PM
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Dick: Thank You for responding.

I have the choke set on the center index point, if I turn it counterclockwise, it would go to the 'lean' side of center per the black dial. What am I missing ?
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Old 07-06-2019, 07:28 PM
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Does anyone else have an idea about this issue?
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Old 07-06-2019, 11:16 PM
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I thought you were talking about a Tripower center carb. Is this a Carter AFB?
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Old 07-07-2019, 07:31 AM
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Dick : It's a 1965 Pontiac tri-power center carb.
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Old 07-07-2019, 10:07 AM
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If your choke cover is marked "Rich" in the clockwise direction, it's the wrong choke cover. Some Quadrajets used a similar appearing cover which is the opposite of the Rochester 2 bbl.

You can make yours work by removing the cover and prying off the thermostatic coil, putting it on backwards from what it is now.

In any case, CCW on a Rochester 2 bbl. is richer!
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Old 07-08-2019, 08:28 AM
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Great Tip, Dick B.

Tom V.
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Old 07-11-2019, 07:32 PM
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Default center carb choke

Dick: Thank You for the info. regarding my incorrect choke cover.What a relief!

Can you tell me how many 'winds' there should be on a 1965 rochester correct choke spring ?

Mine has 9. I have seen replacements for mine that only have 5. How many is correct ? Seems like 9 would create too much force.
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Old 07-12-2019, 11:20 PM
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The center carbs I've taken apart that appear "original" have the 9 turn choke coils. Too much pressure is not the issue. These are thermostatic coils that rotate with heat. I believe any 5 turn or 9 turn coil can be made to work properly.
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Old 07-13-2019, 08:12 AM
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Dick : Thank You for your responses in this thread. You have been a great help to me in regard to the choke issues I have had. Everything seems to be working now as it should. Thanks !
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