/6 Idling Problems

Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download. Tune-up parts and technique suggestions in this thread. Rough idle can also be caused by improper valve adjustment. You may also want to do the Fuel line mod. The hole through the carburetor bore wall is found on some Holley 1920s, Carter BBSs and BBDs, Stromburg Ws and WWs, and other carb designs—not on others. It's not a vent, it influences the calibration of the vacuum-operated transitions (power valve, distributor vacuum advance). See this thread for details.