Need help! Something broke

[10thHawk]

Summerized the boat this evening. Engine fired right up without issue. After a minute or so of running a light and warning buzzer came on. The indicator (not factory, installed by previous owner) labeled "engine raw water".
I started looking around the engine, didn't see anything wrong. Checked all fluids,ect.
As soon as i turn the ignition on, the buzzer and light come on. I started it up again and looked at the drive. The exhaust water was coming out from two holes, one on each side, on the transom assembly, just above those zinc anode nuts that hold the transom assbly on. Would get a pic but its dark now.
I removed the drive and found little pieces of what seems to be rusted metal in the exhaust bellow and some in the prop. Engine ran fine and was not running hot.
Any ideas what is going on here? Any input is much appreciated. 165 merc i/0, alpha one

 

[Bondo]

Re: Need help! Something broke

Ayuh,... Sounds like you found the remains of the exhaust shutters...

 

[10thHawk]

Re: Need help! Something broke

Would that failing cause the water to exit out where i described or might that be a piece of debris clogging the outlet in the drive?

 

[dubs283]

Re: Need help! Something broke

no, the water is supposed to exit there - water shutters are there to prevent sea water from washing back into the engine through the exhaust system

the previous owner may have installed a water flow or pressure switch for the sea water pump and it is below whatever threshold the switch is set for

if you increase RPM does the warning buzzer/light shut off??

 

[10thHawk]

Re: Need help! Something broke

if you increase RPM does the warning buzzer/light shut off??[/QUOTE]

It stays on. It comes on with just the igintion on without the engine running as well. I just tried it tonight, didnt come on when ignition was turned on, but came on while starting.

 

[dubs283]

Re: Need help! Something broke

if you are getting water coming out the back when running on muffs, the sea water pump is doing its job

seeing as how the buzzer/light is going off, it may just be below the threshold of the switch

its up to you - replace the water pump or disconnect the buzzer/light

 

[10thHawk]

Re: Need help! Something broke

The warning buzzer is fixed. It has an aqua alarm which has a piece on the outside of the water passage part and it can be adjusted. I loosened it, turned the key on and slide it around until the beeping stopped. Ran the boat for 20 mins or so and it did not come back on and engine temp was good. Now I guess I have to tackle the exhuast shutter.