hey guys I have a 750 holley double pumper on my car and if i let the idle screw out to much to make the car idle lower it makes this loud whistling noise, now i thought it was the rod that the throttler linkage goes on that goes through the carb and it had a vacume leak but i sprayed starting fluid on it and nothing happened, so i just turned the idle up higher till it went away then put it back down with the secoundary idle screw, its all fine now i am just curious what that was..

 

Air bleeders.

 

what is that? u where a little to general lol

 

Being Holley is made in Kentucky, it's probably whistling Dixie!!

 

Both the idle and main fuel circuits have a small amount of air bled into the fuel flow to help break up the liquid as it is mixed into the air flow. These bleeds, located at the top of the air horn just above the venturi, will whistle under certain conditions. As long as the engine is running well, the whistle doesn't hurt anything for it .

Stock q-jets whistle as well. The stock air cleaners deaden the sound. Open element air cleaners often allow the noise to be heard.