[chr2002ca]

I had the same trouble with 3 new Holley carbs. Two 750 Vac Sec models and one 770 Aluminum Street Avenger model. All 3 had a bog and WOT on a new engine. I had to bump up the squirter size 2 or 3 sizes, change the accelerator pump cam, install a larger CC accelerator pump, and change the vac sec spring. I also bumped up the primary jets one size. After that, the bog disappeared for the most part, but then it ran rich only on idle. I had to do some other tinkering to get the idle to not run rich(was fouling out my plugs), but those are unrelated to the bog issue discussed here. In summary, it took a lot of work to get the carb running right. I could not have done it without installing a FAST dual A/F metering system. I wish you good luck with yours.