First run on used motor overheat alarm

Honda 225. Almost had it ..
Got everything set. Motor starts right up. Ran it on the trailer in the water for 10 minutes, shifted it forward reverse. All seemed good. Tell tale is strong but did notice no water coming out of exhaust holes on rear of engine. Took it off trailer. Ran 5 minutes or so at idle or just above 5mph zone. When I got to open water I gradually increased throttle. At around 3200 rpm alarm sounded constant and overheat light went on, motor went into a limp mode. I immediately throttled down alarm stopped and 5mph back to trailer no more alarm. It seems water should be coming out f the exhaust. Probably thermostats. But would like an opinion. This is my first Honda

Looking for some advice.

Thanks again.

Start with thermostats, could be clogged with salt build up. Those motors don't push water out of the idle exhaust bypass

Are you sure that it was an overheat alarm?

When the 225 overheats, it will go into limp mode (1800 rpm max) for 20 seconds. If over heat situation is corrected, it will go out of limp mode. If temperature is not corrected, it will shut down.

The only other time that the engine will to go into limp mode is low oil pressure, in which case it will go into limp mode and stay there until low oil pressure issue is resolved.

You need to definitively determine which it was.

Well, as soon as the alarm went off the motor started to go into limp I pulled throttle all the way back instantly looked at the warning light that was lit and then idled back to the launch ramp. I didn’t try to rev it up again, I didn’t want a tow. The alarm turned off immediately when I throttled back.
Gonna replace thermostats then on to the next
hope it’s the thermostats.

Results? You can test the T’stats...just put them into hot water and see if they open.

More precisely - the t-stats should start to open at ~140 F, and fully open to 3 mm at ~160 F.

Results. so far. I pulled the thermostats one was just filled with salt or water deposits I should have tested it before I cleaned it but I cleaned it. Tested them and they both worked. I ordered two new thermostat from boats.net and they just came 12 days later . So I am going to put them in today and check it out.

I’ll post when the results are in

thanks

After checking the water pump and impeller the next thing might be to remove the exhaust manifolds and clean the water passages.

Ran it today. No alarm. But only ran for 5 minutes as other problems occurred. But before the new thermostat the alarm sounded as soon as I throttled up.

You probably will not know for sure if that took care of the overheat until you take it out for a long run.