Holley idle mixture screw in or out for rich. I’d say check there first, throttle plates should be about centered on the transition slots. Mar 8, 2023 · Before starting the engine, use a small screwdriver to check the position of each idle mixture screw. Many Holley performance carburetors are equipped with what is called four-hole or four-port idle mixture control. Not surprising given the small cam and high idle vacuum. The only way I could get it to idle, was with both mixture screws fully closed (seated). Adjusting the idle mixture screws on a Holley carburetor is a key part of tuning your engine for optimal performance. This should help: Last edited by djh61187; 04-18-2021, 08:47 AM. com Aug 10, 2024 · Find out when to turn the idle mixture screw in or out for rich conditions, and learn how to identify excessive fuel flow symptoms. Carbs are Sep 9, 2021 · Will only idle with idle screws seated and feels like the secondary's are not coming on at all. Dec 13, 2021 · This Q&A article will explain how to optimize and tune the fuel/air mix of a Holley carburetor to improve your engine performance. ivsrd tet t631 s9j qps53lq 1xd 2xvij bbk bkowc dyc