Alarm sounds, but pumping water fine

[ali'i]

I have a 2000, Evinrude 50 hp, 4 stroke with fuel injection, with under 500 hours. I haven't had it in the water this year, and at the end of last summer had a new impellor and thermostat installed, used it twice for about 6 hours total, last time was early October, then put away for winter. I have run it with muffs for about 5 minutes about every 3-4 weeks since October. It starts and runs fine, but the last time , the alarm sounded after a few minutes of idling . It was still pumping water, but I shut it off anyway, restarted, and it ran fine, then I shut it off. Any ideas why the alarm would sound even though it appears to be pumping water just fine. Don't want to get out on the water if there may be a problem. thanks

 

[Bosunsmate]

air can be sucked in with muffs, best to try in the water, at least in a barrell

 

[boobie]

Agree with the above. There were some of those 4 strokes that had an extra water pick up that you had to tape over when running on a flusher. Don't know if you have one of those or not.