Low water pressure

[ReelThyme]

Good afternoon All,
I am having a problem with my Yamaha F225, in recent weeks I would normally have 18-21 psi water pressure at WOT,
then I noticed it dropped to 15-17 psi (have not changed anything) and now it is hovering around 9-11 for no apparant reason, although the pee stream still looks normal at all RPMs,
I dropped the lower unit and replaced the water pump assy. and that was no help, I even tried another pressure guage with no help.
I have also flushed the water passages, and before I drag it to the shop I was going to replace the thermostats.
Any help with what might be causing this will greatly appreciated,
regards
-Brad

[Hamfisted]

Inspect the thermostats and use new gaskets. But also install the new mushroom head pressure relief valve (use new gasket...). The new PRV is designed to reduce clogging from debris. In the past small shells, rocks, grass, etc... would get stuck in the pressure relief valve and cause it to get either totally blocked or jammed in the open position, allowing water to escape and causing a loss of water pressure. The new valve helps keep debris from getting stuck in there. Its only about $10 for the gasket and everything.


Mike

[Hamfisted]

Please disregard the above post mention of the PRV on the F225 motor. I missed that it was even a 4-stroker. It appears the big block 4 strokers don't use a PRV.


Mike