A QUICK QUESTION ABOUT MANIFOLD VACUUM

CFD244 said

No dial back timing light. I can lean out the mixture with the a/f screws to get into the 13's.

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Since its on the stand, there's only so much you can do. But don't worry about the AFR number. Its just a number, even assuming the exhaust is long enough and the idle conditions are good enough the WBO2 is getting interpretted correctly. A CO meter is better at idle, but again its not important.

For a given timing and throttle position, turn the idle mix screws in until the rpm starts to drop off (or vac drops off), then back out to the point it was before it dropped off. Then I'd make it another 1/16 or 1/8 richer. Now go take a reading and note it down just so you have a record to refer to.