Re: '56 Rochester 4GC

Posted by Steve On 2012/11/6 13:55:32

Hi JP, at the risk of being repetitious, the two idle adjustment screws are only used to further adjust the carb for a smoother idle, at idle. As the speed of the car increases from idle to intermediate speeds and on to high speeds, the idle circuit is no longer in use and you are into the intermediate and power circuits of the carb. Usually the carb idle circuit is out of use around 25 mph. I hope this helps.