Water pump pressure

[Korourke]

I have a aquasport osprey 205 with a Johnson 175 hp 2002 the water pump gauge reads 2 psi two weeks ago I remember seeing 3-4 psi and the telltale signs shows good pressure , should I be concern ,just got the boat and I thought the broker say last year the water pump was replaced but I could be wrong

[Capt. Bob]

I have a aquasport osprey 205 with a Johnson 175 hp 2002 the water pump gauge reads 2 psi two weeks ago I remember seeing 3-4 psi and the telltale signs shows good pressure , should I be concern ,just got the boat and I thought the broker say last year the water pump was replaced but I could be wrong

When does it read 2 psi? On the muffs? In the water?

Water pressure at idle can vary due to water flowing through the muffs. The impeller displaces the water at low rpm so the amount flowing through the muffs can cause a difference in gauge readings. At speed it acts just as a circulation device with the force of the water flowing through the vents contributing to the pressure read on your gauge.

What pressure are you seeing at speed?

[boatnamesue]

Agree with Bob here ^^^.  Water pressure while underway is what you’ll take note of, versus muff pressure.  Be that as it may, with the new to you engine you will only know if the water pressure reading is “normal” by what the previous owner told you.  The calibrated measure wud be the one after you’ve replaced the water pump, thereby knowing its functioning appropriately.   

[Capt. Bob]

Jason is correct.

You will be doing yourself a big favor and creating a warm and fuzzy when using your boat if you know first hand that the water pump, T-stats, lower unit fluid, fuel filter and even the spark plugs have been changed. This is routine maintenance and inexpensive (relatively speaking) that you'll need to be doing.

Good luck.

[Grizzly65]

Question on water pressure. My original 1997 215 DC 200hp gauge is 0-30 psi. When I looked at a new gauge it recommended 0-60 for my model and year? Any thoughts?

[Capt. Bob]

OK,
Just my opinion.
A water pressure gauge is most beneficial at low rpm. This is because at low rpm your water pump  (impeller) works as a displacement pump. The blades are forcing (displacing) the water up into the motor. At higher rpm, the hull is moving through the water at speed and as such, water is being force up into the pump. This force is great enough to physically deform the rubber blades rendering the pump a circulation type. Water pressure will be higher than the pump itself will create. You really want to know that pressure is good at lower rpm to reduce the chance of overheating.
 I think if your water pump is in good shape  and your pick up vents clear (among other things) you'll see around 40 PSI at WOT and maybe more.
That stated, 0 - 60  would work.

[Grizzly65]

Thanks, CPT Bob.