Beeps when flushing engine?

[LeeZeitvogel]

So I ran the boat today in the bay and it did fine, and when I go to flush the engine at the house I hook the hose up turn the water on full blast then crank the engine and only run it at idle speed and like clock work it sounds a constant solid warning beep after about 2 or 3 minutes so I get scared and turn the boat engine off, wait about 5 to 10 minutes and crank it again and 2 minutes into the flush it beeps again. It makes flushing for 10 minutes (like the manual says) a timely procedure, plus am I hurting the engine, and is it perhaps not getting enough water, I don't have a clue why it beeps only when I flush, Any ideas?

 

[LeeZeitvogel]

BTW the boat is a 2002 utopia 205 merc 240 hp.

 

[ForHogan]

Mine does the same thing but....keep in mind there's no value in running the engine while flushing. The flush system is plumbed so that all passageways are flushed even with the engine off. There is more water flow when the boat is in the water, and that's why it runs cooler.

Mike