Mercruiser 3.0 plugs flooded

[Sea master]

As posted earlier engine wouldn't start, pulled plugs yesterday.

One was chewed up the others had water.

How does water get inside to the head where the plugs are?

It seems the engine ingested water. Just want to change everything to make sure it doesn't happen again,

 

[budgie14]

water can get in either blown headgasket,cracked block,cracked/rotten watercooled manifold[going into the inlet manifold,then into the bores via the inlet valves]up thru the exhaust if boat launched too fast in reverse,and the flapper valve broken/worn out,and then into the bore via exhaust valves.usually if its headgasket,you get a milky mess also under the rocker cover..when you say plug was chewed up,what did you mean?was it damaged? if a plug is damaged,its either damaged putting it in,or,youve got serious problems.if you wind the engine over without the plugs in,and disconnect the power supply to the ignition,how much water is ejected from the bores?

 

[Bt Doctur]

Hole rotted thru the head. try removing the spark plugs, take the hose off the therm to manifold (remove the end that goes to the manifold) and rotate it around to it points up, insert hose and turn water on slowly.water should run freely out of a sparkplug hole(s). remove head for further testing.
warped head, bad head gasket, cracked block are other possabilities.

 

[Sea master]

The plugs are already out the #2 the head is completely missing as if something hit it and ripped the spark head off.

If I put water into manifold, and comes out of hole, does it mean that iys the head gasket or a hole in the head?

 

[Sea master]

Thank you guys for all your help tuis forum is amazing.

 

[foreverfishing]

Just had the same problem with my 3.0, unfiortunatly it was the manifold. You can have the mani pressure tested just to be sure.

Good luck