I have a 1996 Mercury 225 OB Saltwater, and after running on plane about 15 minutes, the red check engine/overheat light buzzer comes on and the engine is automatically cut to approx 2500 rpms and boat comes off plane of course! If I turn engine ignition on/off it usually clears the problem, I have full power, and it will run another 10 minutes or so until the same thing happens again.<br /><br /> Plenty of water flow out back port. Its been to the dealer ( Riverside Marine in Edgewater, MD) 4 times and they cannot find a problem ..Dealer has replaced impeller, thermostat, and flushed engine to clear any potential blockages. I asked the dealer to check the temp sensor, but they claim it checks ok. <br /><br />Any suggestions would be greatly appreciated.
When you turn off your motor you may be giving it time to cool down and run properly for a while...