225TXRP: Pressure Control Valve

[carboncow]

It was suggested to replace the grommet on the pressure control valve on an older engine (been sitting 3-4 years) and I see this kit here:

Yamaha Pressure Control Valve

Should I consider the whole kit...or is the grommet the only real concern on a working system?

Now here is the embarrassing part...I have no clue what the Pressure Control Valve does (guessing cooling) or it's location. From the crappy parts list I have it appears to be near the starboard side thermostat, maybe?

I have some images of my engine here:

1988 Wellcraft V20 Steplift - The Carboncow Family

and here:

1988 Wellcraft V20 Steplift - The Carboncow Family

PS. I ordered a Seloc manual, so I'm sure I'll know more in a few days!

[rodbolt17]

the valve is located under that housing with about a 1" hose on the lower stbd side of the exhaust cover.
if the valve isn't broken all you need is the grommet.

[carboncow]

ah the cover between the heads, I see it in the parts list now.

What is the function of this valve...what pressure is in con*****ing and why?

[boscoe99]

The valve limits the amount of water pressure within the block. Too much pressure (blood or water) is not good.

The impeller is designed to create sufficient pressure and flow at low RPM's. At high speed there can be too much pressure. The valve opens and dumps un needed water to keep the pressure down.

If it were my motor, and given its age, I would install all new parts. The valve itself has been redesigned, the spring may be getting weak, and a new gasket is needed no matter what.