Did I do damage to my engine?

[mdchachi]

Dumb newbie here.

I was running at lower power for a while giving a tour of the lake.
Later, I tried to throttle up, the boat tipped back a little but thrust reduced
and it didn't sound like the water was flowing as if the intake was plugged.
There was white smoke billowing out the back when I did that.
Did that a few times before making it back in on low power. I thought
I must have got jammed up with seaweed. The engine itself sounded fine. Not
missing or anything.

So I pull the boat out and see water gushing out of an open plug drain plug
that I had neglected to screw in before launching.
When I looked in the engine compartment, the water was a good foot deep in there.
I couldn't tell if it was touching the engine or not.
I can't really tell how deep it got especially when the boat was tilted back.
The engine never sounded like it was missing, the symptoms were the white
smoke and lack of power. Before I put it back in the water and make something
worse I thought I'd better ask...what I should I do or check? Or should it be ok?

Thanks.

 

[kicker]

I think everyone that has owned a boat for any length of time has done that once. If the motor is still running that would mean that minimal water was ingested. The white smoke could have been the water hitting some warm parts of the exhaust or motor. Or the motor could have ingested some water while it was running which of course would cause it to run like crap and send white smoke out of the exhaust.

If the engine did take in water it should be run again to burn off any moisture that is left in the engine.

I am not that familiar with the Mercs, hopefully Dr Honda will chime in and give his thoughts too.

 

[Dr Honda]

If it was still running... it's probably OK.

I'd pull the spark plugs out, and crank it to make sure any extra water is out. Then... put them back in, and give it a short run. If it seems ok... put it back in the water, and see how it goes.

 

[AirSniper]

I would venture a guess that the white smoke is from extended idle/low rpm - which is normal. The lack of power feeling likely came from the extra weight in the aft of the boat.
I would certainly heed the recommendations above, but sleep a little easier...when I had two heavier people aboard in the rears seats, it felt underpowered as you describe.

 

[mdchachi]

I decided not to procrastinate and took it in for "winterization" today.
The mechanic seemed to think it unlikely the water got in the engine itself and also thought the added weight from all the water was the main cause of the power issue.
So maybe I dodged a bullet. The white smoke was probably from the water shifting backwards and hitting the manifold or exhaust when I throttled because it was not smoking during low RPMs.

Anyway I asked him to replace the bilge pump (which I had disconnected because it was always-on due to the float mechanism failing). I had thought I could always connect it when needed but I hadn't thought that I'd make such a dumb mistake or not detect it taking on water.

Thanks to everybody who answered.