Water Pressure on 2002 150 Saltwater?

[NOLA26]

I just installed a water pressure gauge on my 2002 Mercury 150 Saltwater motor. When running at about 4500-5000 RPM, the pressure is reading around 10 PSI. I'm not sure what the pressure gauge should read. I installed the gauge because of the low tell tale stream at start up and idle. The tell tale flows fine at higher RPMs. So, does anyone know what the water pressure should be on this motor? Also, if anyone knows what RPMs the motor should be at idle that would also be helpful to me.

Thanks for any help yall can give me.

 

[QBhoy]

I’m trying to remember, but without the boat near me just now...I think my Mercruiser runs at about 7kpa at idle and about 30 kpa at 2200 rpm cruising. And I’m sure about 40 odd kpa or more further up the rpm. 40kpa is about 6psi I’m sure. Maybe wrong but I’ll check at the weekend. 10 psi to me sounds plenty. You’re not far off a bar of pressure there (14.7 psi)...which is a fair bit considering it’s an open circuit and little resistance to flow.
My data is taken from the smart craft. Your gauge must be in a particular area of pressure maybe ??

 

[NOLA26]

The pitot tube is connected to the factory water pressure plug at the bottom of the head. The only thing I changed is the threaded connector that allows me to connect the pitot tube directly to the plug. I didn't have an adapter to connect the 5/32" tube with the quick connect to the pitot tube.