Dual Quad 428 CJ

[Khobra]

Originally Posted by patrickt

OK, you know, "eye burning" in the garage is a sign of too lean a mixture, not too rich. In a lean idle condition you do not get a complete burn and raw gas heads out the exhaust. That's why your eyes burn. Just thought I'd pass that along....

Thanks Patrick,

By advancing the time there is more time to burn the fuel. Hence, a cleaner, sweeter smell. Assuming that the condition was rich, would you not agree?
Much has been written and posted about throttle plates exposing too much transfer port thereby causing a rich idle. The solution has always been to close the throttle plates a bit to limit fuel flow from the transfer ports at idle.
By advancing the timing I was able to close the throttle plates at bit and achieving my desired idle speed of approx 950 RPM in neutral and also giving the fuel more time to burn.

[DanEC]

Originally Posted by Khobra

Thanks Patrick,

By advancing the time there is more time to burn the fuel. Hence, a cleaner, sweeter smell. Assuming that the condition was rich, would you not agree?
Much has been written and posted about throttle plates exposing too much transfer port thereby causing a rich idle. The solution has always been to close the throttle plates a bit to limit fuel flow from the transfer ports at idle.
By advancing the timing I was able to close the throttle plates at bit and achieving my desired idle speed of approx 950 RPM in neutral and also giving the fuel more time to burn.

That sounds like a reasonable, thought-out approach to me. I've probably never had a car with a carburetor that idled lean so I wouldn't know if burning eyes is a sign of that or not. If it worked, it worked.

[patrickt]

Sounds good to me. After 40 years of adjusting carbs every which way you could think of, two years ago I tried a method recommended by an 80 year old ex-Ford mechanic and had used this method on my exact carb and my exact cam back in the early/mid 60's. The method sounds so goofy that I won't even bother to recite it here, but it absolutely worked better than my vacuum gauge or the "just guessing" method by backing the screws out the same amount.