It’s pretty hard to get on the mains at idle. Recently I was asked to help a “guy” tune an engine because the carb wouldn’t respond. After about 10 minutes of messing with it I realized it was a Holley 570 4 barrel on about a 450hp stroker. What tipped me off was how any crack of the throttle brought the booster on line. Then I noticed how tiny the Venturi was. But even on that thing it didn’t idle on the mains.
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