Possible issues:
Partially opened tank outlet valve or clogged tank outlet strainer.
Loose clamp on any hose on the pump INTAKE side
Pin hole in any hose pump inlet side. (very low probability)
**SUSPECT #1** Pump inlet strainer NOT properly closed, or cracked due to not being properly drained. (Easily replaced).
Loose screws on pump housing allowing it to suck air (And I might add spit out water)
The above list is in water flow order.
Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times