You have 2 pumps. One near the water separator (low pressure) and one inside the cool fuel box (high pressure). Pressure testing is done at the schader valve up top and should be 38-42 psi.

Low pressure pump is under the alternator on this 6.2 .It would be odd if the 350 MPI doesn't have one

Sn 0m068018. No low psi pump. Service manual 24. 30psi on the rail per merc. Pump will only do 10 now. Relacing pump. Will report back.

Pump and regulator replaced. Regulator was the primary issue. Almost all fuel was returning to the fuel water sep.. I believe this caused the fuel pump to start making noise and eventually lost the ability to keep up with engine demand.

30psi on the rail now, and boat is back running at max performance.

Good to hear. Thanks for letting us know the outcome.

mercury has s/s filter kit to go infront of these pumps, seems to be add-on. make sure you have that to catch trash from getting to pump. the cool fuel pump mounts to copper tube, should come with thermal conductive paste, the bat wing carries heat from pump to copper tube, that pump was designed to be in fuel tank, will overheat if not done.

Ah ha that's what the thermo grease is for. Thanks. I knew there was a reason.