timing/carb questions ¿
Thread Starter
Racer
Joined: May 2001
Posts: 418
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timing/carb questions ¿
After I shut the engine off, it keeps running on. I'm guessing too much advance. Yes or no ¿ Suggestions ¿ My timing is set at 14 degrees BTC.
Next question. 850 Holley DP (new) This carb is running real rich. It has an electric choke. When I start the engine, the black smoke pours out and it idles at 1500 rpm. It slowly picks up to about 2500 rpms and the black smoke gets a little cleaner. I loosened off the 3 screws on the choke and rotated to the right. It idles a little cleaner but at 25 - 2600 rpm.
How do I get the revs down ¿ Suggestions ¿
Thanks in advance!
Next question. 850 Holley DP (new) This carb is running real rich. It has an electric choke. When I start the engine, the black smoke pours out and it idles at 1500 rpm. It slowly picks up to about 2500 rpms and the black smoke gets a little cleaner. I loosened off the 3 screws on the choke and rotated to the right. It idles a little cleaner but at 25 - 2600 rpm.
How do I get the revs down ¿ Suggestions ¿
Thanks in advance!
Race Director
Joined: Feb 2000
Posts: 12,431
Likes: 1
From: CT
Re: timing/carb questions ¿ (2nspire)
did you have any backfires out the carb? this used to happen to my carb. i just had to change the powervalves and keep playing with the idle screws till it went away. i am still not sure what it was.
Instructor
Joined: Jul 2001
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From: Bklyn,Ny U.S.A
Re: timing/carb questions ¿ (2nspire)
I am not familiar with the holley 850 but recently bought a holley street avenger.Should be the similiar.The fast idle screw on that is located behind the choke it is in a tight spot.If u stand in front of the choke it is at around 8 o clock towards the rear of the motor.Do u have a msd ignition box?
Thread Starter
Racer
Joined: May 2001
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Re: timing/carb questions ¿ (79 vette)
I'll check out that screw. Thanks. No, I don't have an MSD. I had the 6al but took it back. Am looking at a Crane, I think. Not sure yet but I'm sure I'll have some kind in the near future.
Tech Contributor
Joined: Aug 1999
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From: At my Bar drinking and wrenching in Lafayette Colorado
Re: timing/carb questions ¿ (2nspire)
2n -
Run-on after engine shutdown is most commonly caused by excessive idle speed. GM issued a service bullitin on this back in about '75. Set your idle speed down as far as you can stand it. If this does't work, use an idle-up solenoid to set the idle speed when the ignition is on to the proper rpm. Then, set the idle speed screw on the carb at the lowest rpm that the engine will stay running at. When you shut the engine off, the idle-up solenoid will de-energize, the idle will drop down to the idle speed screw, and the engine will not run on.
Run-on after engine shutdown is most commonly caused by excessive idle speed. GM issued a service bullitin on this back in about '75. Set your idle speed down as far as you can stand it. If this does't work, use an idle-up solenoid to set the idle speed when the ignition is on to the proper rpm. Then, set the idle speed screw on the carb at the lowest rpm that the engine will stay running at. When you shut the engine off, the idle-up solenoid will de-energize, the idle will drop down to the idle speed screw, and the engine will not run on.
Thread Starter
Racer
Joined: May 2001
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Re: timing/carb questions ¿ (lars)
79 vette Thanks. I did go out and check for the screw. It is there and I'll try it tomorrow.
Lars Thanks. I had the idle set to 800 as per the book. It barely run there. Then I put it to 1000. I'm still not used to the lumpy idle and with me having starter turning over problems, I didn't want to accidentaly stall it. I changed starters tonight when I was looking for the high idle screw. I'll have to check this out tomorrow.
Lars Thanks. I had the idle set to 800 as per the book. It barely run there. Then I put it to 1000. I'm still not used to the lumpy idle and with me having starter turning over problems, I didn't want to accidentaly stall it. I changed starters tonight when I was looking for the high idle screw. I'll have to check this out tomorrow.
