That would be the first thought, which is why I included all the data I could think of. The AFR gauge on the dash doesn't agree with you ... nor is there any black smoke even on flooring it, or pig-rich smell to the exhaust at idle. If that much gas were leaking somewhere it'd be easy to find by nose and by eye.

I think it's just operating in an inefficient rpm range for much of my testing (3500 and below), plus working both those accelerator pumps a lot of the time