Jet noise

[motorbreath]

hi im new here so hello . i have been reading some forums very good information . I was wondering if anyone could help . I have a doen DJ80 jet with a 350 chev in a 19.19ft fishing boat. i took it out for a run a couple of weeks ago it was making a werring noise so i decided to go out any way . The boat over heated didnt go either (3000rpm 8knt) . so got home pulled her apart changed the rubber cutlass bearing put it back together . back on the water started still the noise but the jet was pumping water running good no over heating. but when i slowed down the jet was slowing almost to stall the motor . when i started was hard to turn motor at first but started fine. would the thrust bearing be causing this? if anyone knows or ahs advice i would much like it ... cheers