Question for Don - Water pressure way too high and overheat alarm

[ChiefManyRises]

Don,

posted on here a couple weeks ago and just trying to follow up and narrow this down as I'm getting frustrated. History - sucked up some weeds and had overheat alarm going off in addition to high water pressure.

Replaced thermostats previously and then the Water Pump Saturday. Went for a test ride after and water pressure still way too high. 7-8 psi at idle and when running 30 mph at approx 3500 rpms water pressure is showing 30 psi. Ran approx 4-5 mins just cruising and had overheat alarm come on again. Shut her down and slowly went back to the ramp.

Got home and pulled the hoses that come from the thermostats and made sure there were no obstructions - none found. Pulled the thermostats and flanges off and just ran water through the block and just let it flush using the hose flush access. Didn't see anything come out. Put everything back together and hooked up the earmuffs and for the first time it actually seemed like the poppet and thermostats worked like I have read they're supposed to. At first there was no tell tale until approx 30-45 seconds after the engine was running and warmed up. Prior to replacing the water pump and thermostats the tell tale always peed even on start up.

Getting ready to take it in and have it checked out but wanted to see if there were any last minute things I could check myself before handing over the check book Thanks for your time.

2000 Mercury 225 EFI OT165529


Modified by ChiefManyRises at 10:19 AM 5/9/2011

[EuropeanAM]

Have you removed/inspected/cleaned the POPPET VALVE?

The Poppet Valve is what controls water pressure from approximately 2000 RPM through WOT....

A sticking poppet, debris in the poppet, etc. could cause your problem.

Poppet valve is located in the Starboard side of the adapter plate (remove lower STB cowling to access it).

[ChiefManyRises]

That's what will be checked next. Did the water pump and thermostats. Can it be removed/inspected without having to replace gaskets or anything else? Thanks.

[EuropeanAM]

You'll want to have (2) 88907003 gaskets on hand (at least). Probably a good idea to obtain the diaphram, gaskets, poppet, spring, and grommet (for the seat), and simply replace them while you're in there.

Not real expensive.... if you need the components, drop our parts department an email.

[ChiefManyRises]

Cool deal. Thanks.