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Old 11-21-2010, 02:09 PM
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Location: NE Oklahoma, OK
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Quote:
Originally Posted by cdnus View Post
I'm certainly no expert, but I think that is a vacuum secondary carb (correct me if I'm wrong) It sounds like you are getting the effect you describe when they are opening. Perhaps some spring adjustment is required to make the transition smoother. To me 12.5 is rich for W/O on a 2500? lb. car.

JMO

Craig
wide open isway too rich unless you have a supercharger, in which case it's just rich. I also think your cruising a/f ratio is too rich. 14 or even 14.5 is better. with the throttle barely cracked open and the rpm low you are not really making much HP & can run a lean(er) mixture without worry.

Now a 14.5 a/f mixture at 3500 rpm under a load like a long incline would be too lean in my experience.

I would reduce your main primary jet until the mixture is 14.0 to 14.5 at the 2000 rpm cruising scenario. After you have that where you want it, then reduce the size of the secondary jets until you have a wide open a/f ratio of 13.5

only make one change at a time.


Z.
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