carb adjust & timing, what order - The 1947 - Present Chevrolet & GMC Truck Message Board Network

dukcaln · 10-11-2011, 12:28 PM

Ok, finally got access to a vacuum gauge and will be adjusting the carb and timing again since I fixed my header leak and vacuum leaks! So my questions are the following:

1) What order first, timing or carb?

2) Using the vacuum gauge where do I want to see the vacuum at, highest possible right? Once I reach that making adjustments on the screws do you have to back off and turns before setting it?

3) Were are most of you setting your idle at and is the idle setting the last thing?

4) If I missed anything on the vacuum gauge process, a step or how to please advise.

Hoping to start doing this in a couple hours. Thanks all

webfoot · 10-11-2011, 12:36 PM

1. Adjust the timing first.
2. correct. 1.5 turns out is good for starters, test and adjust via vacuum readings from there.
3. Depends on your camshaft specs. yes.

57larry · 10-11-2011, 01:08 PM

Quote:

Originally Posted by webfoot

1. Adjust the timing first.
2. correct. 1.5 turns out is good for starters, test and adjust via vacuum readings from there.
3. Depends on your camshaft specs. yes.

X's 2

longbed67 · 10-11-2011, 01:17 PM

x 3

fastwillie 696969 · 10-11-2011, 01:28 PM

x4

dukcaln · 10-11-2011, 01:40 PM

thanks all so my only not so sure is this...once we are adjusting the screws on the carb to get the highest vacuum and reach it, we back the screws in 1.5 turns and leave it? What is the average vacuum for a high we can expect?

webfoot · 10-11-2011, 01:45 PM

No, for starters turn the screws all the way in (not too tight!) and then back out 1.5 turns. That usually gets you close, then leave wherever you get max vacuum reading. Vacuum will depend on your cam which you have not provided specs for.

dukcaln · 10-11-2011, 06:20 PM

all went fairly well except I had some issues with the needles.... will post in another thread

10-11-2011, 12:28 PM	#1
dukcaln Registered User Join Date: Jul 2011 Location: vacaville ca Posts: 1,304	carb adjust & timing, what order Ok, finally got access to a vacuum gauge and will be adjusting the carb and timing again since I fixed my header leak and vacuum leaks! So my questions are the following: 1) What order first, timing or carb? 2) Using the vacuum gauge where do I want to see the vacuum at, highest possible right? Once I reach that making adjustments on the screws do you have to back off and turns before setting it? 3) Were are most of you setting your idle at and is the idle setting the last thing? 4) If I missed anything on the vacuum gauge process, a step or how to please advise. Hoping to start doing this in a couple hours. Thanks all __________________ 04 CHEVY LLY LS DURAMAX 4WD. MODS TO FOLLOW, EFI LIVE, BUILT TRANS, LBZ MP, LIFT PUMP *SOLD* 1972 chevy c10

10-11-2011, 12:36 PM	#2
webfoot Registered User Join Date: Nov 2007 Location: Hermiston, OR Posts: 947	Re: carb adjust & timing, what order 1. Adjust the timing first. 2. correct. 1.5 turns out is good for starters, test and adjust via vacuum readings from there. 3. Depends on your camshaft specs. yes. __________________ *Running in place gets you nowhere fast.* -me 1968 GTO 4-spd covnvertible 1970 K-20 4-speed, factory AC.

10-11-2011, 01:17 PM	#4
longbed67 Registered User Join Date: Jun 2011 Location: Monroe, WI Posts: 1,415	Re: carb adjust & timing, what order x 3 __________________ *Adam* My 1967 C10 - Turbo 250 Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=485843 (608) 214-8706

10-11-2011, 01:28 PM	#5
fastwillie 696969 ~Rest In Peace~ Join Date: May 2005 Location: CALIFORNIA NOR CAL Posts: 9,707	Re: carb adjust & timing, what order x4 __________________ is it fast ? it has a lighting bolt donut? B___H please, I can remove 90% of your so called "beauty" with a kleenex

10-11-2011, 01:40 PM	#6
dukcaln Registered User Join Date: Jul 2011 Location: vacaville ca Posts: 1,304	Re: carb adjust & timing, what order thanks all so my only not so sure is this...once we are adjusting the screws on the carb to get the highest vacuum and reach it, we back the screws in 1.5 turns and leave it? What is the average vacuum for a high we can expect? __________________ 04 CHEVY LLY LS DURAMAX 4WD. MODS TO FOLLOW, EFI LIVE, BUILT TRANS, LBZ MP, LIFT PUMP *SOLD* 1972 chevy c10

10-11-2011, 01:45 PM	#7
webfoot Registered User Join Date: Nov 2007 Location: Hermiston, OR Posts: 947	Re: carb adjust & timing, what order No, for starters turn the screws all the way in (not too tight!) and then back out 1.5 turns. That usually gets you close, then leave wherever you get max vacuum reading. Vacuum will depend on your cam which you have not provided specs for. __________________ *Running in place gets you nowhere fast.* -me 1968 GTO 4-spd covnvertible 1970 K-20 4-speed, factory AC.

10-11-2011, 06:20 PM	#8
dukcaln Registered User Join Date: Jul 2011 Location: vacaville ca Posts: 1,304	Re: carb adjust & timing, what order all went fairly well except I had some issues with the needles.... will post in another thread __________________ 04 CHEVY LLY LS DURAMAX 4WD. MODS TO FOLLOW, EFI LIVE, BUILT TRANS, LBZ MP, LIFT PUMP *SOLD* 1972 chevy c10



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