I picked up a new factory refurbished 2300 from the Holley store on Ebay. Right out of the box it shot fuel through the vent. I called tech support and they said sent it back. Naturally at my expense. They checked it out and sent it back to me. I installed it today and low and behold it’s shooting fuel through the vent again. I swapped out the needle and seat from a new Holley rebuild kit and still the same issue. I am using a mechanical fuel pump with two filters before the carb so I don’t think the fuel pressure would be an issue. Any ideas on what it could be? I’m hesitant to send it back unless they pay shipping or offer a full refund.