Holley idle mixture screws
That's a likely possibility and good way to describe it.
The longer explanation is the idle circuit feeds both the transfer slot and then the idle mix screws which control fuel to the idle port.
These carbs are designed to draw fuel from both the transfer slot and the idle port at slow idle.
When the throttle opens, already having fuel flowing from the transfer slot reduces the delay in increasing fuel to match the additional air.
If they are too far open at idle, then transfer slot happily supplies all the fuel the engine needs to idle.
So the first thing to check is the transfer slots visible under the throttle at idle are in the range of .020 - .040"
You can check with feeler gage or drill bits.
While you're at it, write down how many 1/4 turns in of the idle speed screw from just touching gets .020, 030, and .040. Then you'll always know how far open the throttles are.
That's a likely possibility and good way to describe it.
The longer explanation is the idle circuit feeds both the transfer slot and then the idle mix screws which control fuel to the idle port.
These carbs are designed to draw fuel from both the transfer slot and the idle port at slow idle.
When the throttle opens, already having fuel flowing from the transfer slot reduces the delay in increasing fuel to match the additional air.
If they are too far open at idle, then transfer slot happily supplies all the fuel the engine needs to idle.
So the first thing to check is the transfer slots visible under the throttle at idle are in the range of .020 - .040"
You can check with feeler gage or drill bits.
While you're at it, write down how many 1/4 turns in of the idle speed screw from just touching gets .020, 030, and .040. Then you'll always know how far open the throttles are.