Over heat alarm on a yamaha

Hey guys, I posted a while back about an over heat alarm I was getting on my 2003 70 hp 2 stroke the conclusion then was to start with an impeller kit and go from there, so I did that and I’m still getting an alarm. Today I idled away from the boat landing for probably 200 yards and the alarm started going off. I’m assuming it has to be an overheat alarm and nothing to do with the oiling system because it takes a bit of a drive for the alarm to go off. Agree? When I did the impeller I got maybe a tablespoon of sand out of the lower unit, do you think there might be sand in the engine? Problem with the sensor maybe? I pulled the thermostat and it was clean, not sure if it is working like it should, but I can’t see any signs of a blockage there. This problem has cost me 3 days on the water, I need to get this figured out any help would be appreciated. I’m kinda starting to think those sailboat guys got it figured out Another thing I noticed today was the exhaust port under the power head (intermediate port?) had some water spitting out of it, any idea if that is normal? Thanks guys

Your lower unit could be plugged with sand or mud. My yamaha 225 had a hose fitting that you could disconnect and attach a garden hose to flush the system. Look at the water intake too and see if you can see if it is plugged

1. Make certain you did the pump correct and then flush the motor.
2. pull the thermostat and run it on the water.
3. If you still get the alarm then pull the thermostat housing cover and run the motor while on the water. water should pump out.

I had my sensor fail a few years ago. I knew it was not the pump as I replaced it, removed the thermo AND the alarm would start as soon as the motor started. They do fail.

In all it should not take too long to do your tests on the water.

Are you sure its an overheat alarm? I had a 2 stroke evinrude that the alarm would go off after I ran it a bit. Turned out that the sensor was bad in the top of the oil tank. Not sure what you call that, oil pump? Guy that worked on my boat couldnt figure it out until he ended up calling a dealership and talking to a technician…

I think I found it!!! The wires coming out of the top of the oil tank for the oil level sensor were routed too close to the flywheel. The flywheel cut one of the wires and chaffed another. No sailboat for me! Thanks for the help!