Tuning

First adjust your timing, then do the carb. I like to do timing first because timing is a set number that isn't affected by anything else (for the most part). It is possiable that your best mixture setting will different at 6 degrees BTDC, then at 10 degrees BTDC.

-Shaun

I do it with the vacuum advance off, but you should not have any vacuum on idle (if you do, then something is wrong). The vacuum should come off idle (1200 RPM or so I think). Disconnect the hose and plug it up (a golf tee works well) and plug up the vacuum port on the carb, then set your timing. What I do for the mixture screws is turn them clockwise until the bottom out, then back them out 2 full turns (720 degrees). Once you have done that, start the engine and start turning one of the mixture screws clockwise until the engine starts to get a rough idle, then back it off until it smoothes out, then do the same for the other one. I like to give it a little extra 25 to 20 degree turn after that, just to richen the mixture up a little. This works well, but the best way to tune your carb is by exhaust gas readings. I used the smog machine at work to tune my carb by measuring CO2, O2, ect. I know Summit has a little device that lets weather you're too lean or rich, but I donno how well it works.

my66coupe said:

With a edelbrock carb, Do you set the timing with the vacumm advance hooked up? Ive been setting the timing with the vacumm advance off and when i put it on, it throws my idle off. Help!

Mike

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Does the port that your vacuum advance is plug into have vacuum at idle?

-Shaun

my66coupe said:

Well I was using the full time vacumm advance port. Switched over to the correct port and all is good. I will get my mixture dialed in tommorow. Thanks

Mike

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Good to hear.

-Shaun