Water Pressure Gauge

[fixmyevinrude]

1988 Evinrude XP


Just wondering what a water pressure gauge should read. This is my first boat with a water pressure gauge. Presently it reads about 3 psi @ idle and about 12 psi @ 4500 rpms.

 

[gm280]

That really determines where you are taking the reading from. BUT, that sounds about right from my old Bass Boat setup I had. So I think you're good to go, How you have to use that gauge is get a baseline of readings now on the engine with everything running well. Then IF those readings seem out or totally different down the road, you have an issue... JMHO!

 

[emdsapmgr]

These V4/V6 impellers are very robust. Last for years and still pump. My new impeller on my V6 crossflow runs about 6+ lbs at idle and over 19 lbs at 5000 rpm's. With 5 years on it, still pumped 4-5 at idle and 17-18 at idle. No telltale, just direct hookup to the pressure gauge. So yours is low. You may not get a hot horn, but your impeller is at the bottom end of it's life cycle. I'd replace it.

 

[fixmyevinrude]

Wow emdsapmgr, that really surprises me. Just put a new impeller in about two months ago and had it out for five days at Table Rock. Boat ran well but it is new to me. Its a 150 xp. I will definitely check things out on it. I did notice that water sputtered out of it until about 4000 rpms then it poured out of the two rear ports above the water line. The telltale is hooked up and streaming well.

 

[emdsapmgr]

If you have a water pressure gauge "t'd" into the telltale, that can sometimes change the real water pressure. To validate the pressure hook the pressure gauge line direct to the telltale hose barb on the exhaust cover. No "T." Once the engine starts, you should almost immediately get a strong telltale stream at idle. On the flatback engines, you will get a water stream out of the exhaust relief ports at higher rpm's. That's normal. Also, I've see water pressure gauges that get frozen of the the winter. If there is any residual water in them, the freezing water can bend the arm connector between the bladder and the gauge needle, causing an incorrect reading. If you don't know what it should read, you may not notice the 5-10 lbs difference in the reading when you run it the next spring. If it's a new impeller, I'd try another water pressure gauge. Seems like I have to replace mine every 5-6 years for that reason.

 

[bob johnson]

I have my pressure fitting in the head on my 1995 115 Ocean Runner. it reads about 10 at idle and over 20 at WOT... and I have had the same pump in there for 4 years!!

bob

 

[fixmyevinrude]

I installed a new Water Pressure Gauge (Faria 0-30 PSI) as emdsapmgr suggested with some improvement in results. Reading about 3 PSI at Idle and 15 PSI at 5000 RPMs. I am not hooked up direct as my telltale is still hooked up and the gauge comes off a T. Am I in the safe range or should I be looking for ways to improve pressure?

 

[emdsapmgr]

You don't want the max water pressure below 10 lbs @ WOT. 15lbs is better. Test it by plumbing the gauge direct to the telltale hose barb and see if that makes a difference.