Related Photo Galleries
17a During dyno tuning, the idle/cruise A/F became too rich from jetting up to obtain that ideal WOT (wide-open-throttle), high-speed A/F of 13.0 to 13.1. We noticed the idle/cruise A/F changed from a baseline 13.3 to a pig-rich 11.6 during steady cruising on the dyno. An acceptable idle/cruise A/F on a carbureted high-performance motor is roughly 13.1 to 14.5:1. Not wanting to develop a flat spot in the transition of opening the throttle blades when going from the idle/cruise circuit to the high-speed circuit, we needed to be conservative with the size change of the idle/cruise air bleeds.