I'm not a minibike fuel pump expert.
but i have had a lot of success using minibike fuel pumps.
every minibike fuel pump i have seen, needs a vacuum pulse from the intake manifold.
Taking it from anywhere else is pressure, not vacuum.
Not sure why people just hook the fuel pump up to whatever they happen to see?
My fuel pump needs a vacuum pulse, which requires an intake manifold with a vacuum fitting.
intake can be drilled/tapped to accept a barbed fitting
Lower line is vacuum, upper line is fuel to carb. Motor turned over 9k RPM with zero fuel issues.
"the front of the block"
is not the proper place to power the fuel pump imho.
you need a vacuum source.
Also filter should be before pump in my experience
you are trying to apply a pressure signal (crankcase pressure) when a vacuum signal (the complete opposite and is only generated by the piston at the intake manifold) is required.