Yes, you need to replace fuel pressure regulator..Im thinking that is your issue..
Ayuh,.... Unplug each sensor, 'n see which one shuts off the buzzer,.....
Before spending any money be sure and check the gearbox and driveshaft. Can you pull the prop and is there good gearoil in the gearbox. The impeller certainly
On the trailer and in gear it is actually still in nuetral.-----the prop does not have to do any work !---------Check compression and spark fo all cylinders.
Skooter, I replaced the low pressure fuel pump and measured fuel pressure. I got the actual Honda pressure tester. I get 80+ PSI no matter what I do