You just learned a lesson in fuel pump flow ratings, and how the rest of the system affects what’s actually available to the carb after all those fittings, the line, the regulator, etc.

Looks like you’re system pressure would have been just under 2psi at wot/full power.
Most carbs don’t work great like that.

Time for a bigger pump.
Get something that’s absolutely big enough.

Is what you have now mounted in the tank?