575 Sci fuel pressure

Troubleshot this about a month ago. I recall at idle 34# if you remove the vac.line it will be 38#. IF YOU ARE RUNING THE BOAT UNDER LOAD, IT WILL READ 26-28# MY UNDERSTANDING IS THAT I'TS MAPPED FOR A FALLING FUEL PRESSURE. That was my concern at the time seeing the fuel pressure low under load. Mark @ Precision Marine gave me the info. on the falling fuel map.
 
Merc Service Manual says: Mechanical Pump 3-8 PSI and Electric Pump 34-38PSI. Didn't see anything diff @ WOT.
 
when I spoke to Bob at mercury racing he said 26-28 Psi ?????? I keep getting numbers all over the place, I would like to know what people are actually at (psi?) on there guages that have 575 Sci.
 
I just go a copy of the H.P. 575 Sci Specification manual and is says in the 3rd page "fuel rail pressure" idle 28 Psi and WOT 26 Psi and on page 6 under the Fuel System Specifications is says Fuel Pressure Regulator setting 30 Psi.
 
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