[jashou2003]

What is the normal water pressure range I should see on my pressure gauges when @ 4500-5200 RPM's. I notice that both starboard & port motors are @ around 15-17 psi when running @ these RPM's. I just recently purchased this boat & comparing it too my buddies twin 225's Evinrudes his are around 35-40 psi. I know they are completely 2 different motors Merc & Evinrude but was curious on the matter. I'm getting a great flow of water coming out of both motors @ idle & @ high RPMS. Not sure if gauges are bad, or if I have a semi clogged line. Have'nt installed the new gauges yet not until I replace both water pumps / impellers. Hopefully this will solve my crisis. Any info would help.

[Dead Eye]

^

[gss036]

From my personal experiences, that is about normal, my Merc manual for my 89 200 hp shows 12 psi at WOT. I have seen some that will go to about 22psi. If you don't have a manual, call a local Merc shop and ask them what it should, different motors have different specs. Evinrudes have always had higher water pressures.If you the water pump has not been done in the last 2-3 yrs, that definately would be 1st place to start, along with the thermostats.

[jashou2003]

Thanks alot gss, I guess I could save myself alot questions IF I had a manual. I need to get one to have personnally. It will save me the trouble of always trying to troubleshoot & ask questions. So you recommend doing the thermostats as well when I do the water pumps. I guess it would make sence, it all about the cooling.

[Silvertip]

My 75 Merc has the pressure gauge T'd into the tell tale and reads 7 PSI at idle and 15 PSI at 3500 - 4000 with a new impeller. I think your readings are normal.