Water pressure Merc. EFI - 150hp

[Ray 2000]

I just installed a new water pressure gauge on my Ranger for the 1999 Mercury EFI 150hp The pressure seemed low to me so I called Merc. to get some advice. Mercury faxed me specifcations.<br />Nothing until warmed up then: Idle 1 to 3 psi. Poppet valve opening 4 to 9 psi and wide open 12 psi. The engine is designed that the pisser stream comes out AFTER it's gone though the block & motor and will have no pisser stream until termostat opens up.<br />Just passing along the info so nobody else needs to worry.<br /> Many thanks to Marine Doc for his help with gauge!

 

[Kenny Bush]

Re: Water pressure Merc. EFI - 150hp

You are correct sir....... I have come to learn that a water pressure guage is more valuable than a temperature guage. You will also see the pressure go down after a couple of seasons, indicating a need for a new impellar.

 

[rodbolt]

Re: Water pressure Merc. EFI - 150hp

hello<br /> your not the first one that has been scared because the water tell tale did not start right away. I get 4 or 5 service calls a year only to get to the dock and tell them its ok. keep up the posting of good to know information <br />PS you should see some motors in the winter when the water temp is 32 degrees