Starboard Head Overheat

[TX Strampion]

Engine Serial Number: 1B809127
Year/Make/Model: 2011/Mercury/225 ProXS
Prop you are Running: Tempest Plus 25P
Current Maximum RPM: 6000
Idle and WOT Water Pressure Readings: Don't know
Smartcraft or Analog Instruments?: Smartcraft

When I start and idle the engine at the beginning of a the day, the smartcraft alarm sounds with a continuous beep and STBD HEAD OVERHEAT appears. The engine temp spikes (around 155, I believe). Once I get above idle, the temp drops and the alarm goes and warning stops. It doesn't happen again for the rest of the day. This has happened on the last several trips. I replaced the poppet valve and I'm confident that I seated it properly, but it did not resolve the issue.

Any advice on a possible cause would be appreciated.

[lpugh]

got to know what the pressure is
Replace water pump
clean strainer
test thermostats in hot water to be sure they do open at 130 degrees
may have power head gasket failure, leaking at rear of motor to adaptor plate, may be visible with cowlings off, may be leaking into exhaust and not visible, low water pressure at idle with a known good new pump is a sure sign of this

[JOE54]

^^^^ check thermostats closely

[leonreno]

Swap thermostats from one side to the other, if problem moves to port it is your thermostats.

[EuropeanAM]

Folks: ANYTIME you have a COOLING SYSTEM PROBLEM or Overheating, you should ALWAYS, ALWAYS Start at the SOURCE: The Water Pump.

ONLY after this has been done, and problems PERSIST is it appropriate to start looking at other causes.

Note: Water Pump is an ANNUAL Maintenance item on this engine (once every 364.99 days, or 100 hours of operation, whichever occurs FIRST).

[DewRonInc]

Yup, I always swap mine about every two years or so, seems they always kinda stick after a bit. New ones, no more sticking, plus a new water pump yearly or more