make sure there is water
get video cam ready. turn on pump
video the pump in action and video the outflow from hull.
then post all for us to critique.
catalina 27 may have stern mounted outflow thruhull fitting.
that would pass under cockpit
to transom and there will be a lovely plastic looking or bronze ring where it exits.
please video the pump in action so we can properly critique the issues and your videography. you know that will happen.
if you wish privacy , send pm.
there are a few things that could be the issue. each one has different water