"I have a 2000 Mercury Optimax
"I have a 2000 Mercury Optimax out board motor and after about 10 minutes of running at almost full throttle the buzzer goes off and the engine shuts down and the temp gauge reads 220-250 degrees, yet the motor is cool and not running hot. I've checked everything out and put a new water pump on it this week. It didn't change a thing. I can run it all day at 4 MPH and it's fine but anything over 1000 RPM and it shuts down. Any suggestions????"
"I have a 2000 Mercury Optimax out board motor and after about 10 minutes of running at almost full throttle the buzzer goes off and the engine shuts down and the temp gauge reads 220-250 degrees, yet the motor is cool and not running hot. I've checked everything out and put a new water pump on it this week. It didn't change a thing. I can run it all day at 4 MPH and it's fine but anything over 1000 RPM and it shuts down. Any suggestions????"