Manifold Vacuum Experiment

RustyRatRod said
LOL What would be the effects of just removing the check valve? I've seen people talk about it. Easy to see why it's there. To keep fuel from running back down so there will still be fuel right at the nozzle. That's why I've not removed it.

The check valve (weight) helps to prevent the air flow through the carb from pulling fuel from the accelerator pump nozzels due to venturi action.