Slant 6-- New Carburetor and loss of power

[Photon440]

I'm willing to bet ($2) that the accelerator pump is in fact not giving enough gas, then the motor catches up. Can you do any adjustments to make sure that the pump lever is getting the full stroke, and it starts right away with butterfly opening? Getting a good pump shot will help the cold starting troubles as well. Why not hook up the choke?