225 promax low water pressure

[Joeys]

Hello everyone. I have a new to me 1995 Allison xb2003 that I put a 2000 225 promax on. Boat has low water pick up and nose cone and prop shaft centerline is 1/4 below pad with 14 inch set back. I have new water pressure gauge and tubing. New water pump also. My water pressure tubing is on the top of exhaust cover plate. Engine idles in gear at 7 lbs and out of gear at 10 psi and have seen it up to 12 psi, 900 rpm out of gear and 650 to 700 in gear. Running down lake it never gets above 10 psi. I have new water temp gauge and sender. Engine will idle at 150 degrees and once on plane will drop to about 110 and never get higher. I don’t run it wide open as I’m learning to keep it on the pad. Most I turn it is about 4500 to 4800 rpm or so as it gets on pad about 55 to 60 mph. Temp sender is in top of head by one of the thermostats. I just wonder why water pressure is so low. Boats I’ve had in the past would idle around 7 psi and 20 or so running on plane. Any body having some issue and what fixed it Tia

[Brad Zastrow]

With the 2.5's I have owned in the past 10 pounds is enough at speed. So long as the temp stays at 150 or less you should be fine. I have had motors that idle at 2-3 psi. So long as the water comes out of the piss tube and you are not overheating all is good.

[Joeys]

Thanks I’m really not having any issues. Piss tube is pissing so all is good there. Just don’t like the 10 psi running. Thanks for replying!

[Baker343]

Is your Promax also new to you.
Does it have a 2 piece or 1 piece exhaust plate.

[Joeys]

Is your Promax also new to you.
Does it have a 2 piece or 1 piece exhaust plate.
Yes pro max is new to me as well. Bought boat with blown powerhead. It is a 2 piece.

[Baker343]

2 piece is good. Have you checked your thermostats yet, you may have washers. Sounds like your moving water to fast and not holding it in your block long enough to generate some heat.

[Joeys]

2 piece is good. Have you checked your thermostats yet, you may have washers. Sounds like your moving water to fast and not holding it in your block long enough to generate some heat.
I have ordered new thermostats and poppet valve. There are no washers it has thermostats. Thermostats appear to work correctly considering it will get up to 150 while going through idle zones. I took poppet valve off and replaced it with the one off my blown powerhead till the new one comes in. I’m going to try it tomorrow and see how it goes. Call me crazy but the poppet that was in it was easy to open aka not a lot of spring pressure, easier than the one I took off blown power head. I kind of think that the screw that goes through diaphragm wasn’t tightened all the way. I took it apart and when I reassembled it it looked shorter. I don’t know maybe I imagined that. Anyway it has a different poppet in it now and different thermostats

[Baker343]

Sounds like your on the right track.
I like to see between 15 to 20 psi at WOT.
That generally creates enough heat to avoid cold seize

[Joeys]

Took boat out today and idling water pressure was 12 psi out of gear and 8 psi in gear. On plane at 4000 to 4800 rpm was 15 to 20 psi and water temp was 125. Water pressure would fluctuate if I had to much negative trim but I would say it is much better, thanks for the feed back