Part throttle/low rpm "bogg/surge"

Hi. I hope this will help.
You cannot shut the secondary butterflies prematurely. They require to be open to meter fuel through them. If you shut them too low or completely you will stop the fuel flow in the secondary circuit. this will put the secondary circuit to "sleep" so to speak. So if you you accelerate or put your foot down you will stumble till the secondaries wake up upon the cracking open of the butterflies. There will be a delay. Both Holley and Demond carbs have separate fuel bowls thus both requiring constant metering to circulated fuel through them. If you don't meter the secondary fuel and drive constantly light footed you will never open the secondaries. (for months on end unless you are a lead foot). This will clog up your secondary fuel circuit. There is a procedure to adjust the butterflies on the secondary to the correct opening. You cannot veer from this adjustment. (small tolerances permitted). If your idle is too high adjust the primary butterflies only. If your idle is still too high, and the primary butterflies are COMPLETELY shut, you might have a leak somewhere or the secondary butterflies are adjusted too open. Pull the carb off and check the adjustments, and then check the timing and make sure its on the ported vacuum not the full vacuum connection on the carb.

Regards
Billy D...