Posted: June 23 2008 at 20:03 | IP Logged

I have a 1995 Monarck 24' Deck Boat, with an OMC Cobra stern drive I/O. It is a V-8  5.0 L  Engine. I was in the process of tuning up the engine when the rains hit. I had removed 1 spark plug to match it at the parts store. Thought my automatic bilge system would take care of any rai acummulation, but didn't realize the batteries were dead. I now have water in that one cylindar and am also concerned about the starter which was completely submerged. Should I be concerned about any other components and what can I do now to repair damage to the cylindar and possibly save the starter? I am mechanically inclined but I have never delt with this type problem before.

Any advice would be greatly appreciated.

Thanks, JIM

Posted: June 24 2008 at 09:29 | IP Logged

Hi Jim, I've had these problems before. I turned one car into a submarine TWICE and resurected it once (the second time the water in the cylinder bent a rod and although it started, it knocked bad). My boat has gotten water in the engine from bad shutters, or, because the exhaust elbows are not high enough above the water line (haven't figured that one out yet).

If you haven't gotten the water out of the cylinder already, that should be your first priority. The easiest way is to turn the engine over by hand with a wrench on the harmonic balancer bolt if necessarry. Taking all the spark plugs out would make it easier and you're putting new ones in anyway. Turn the engine over a few times by hand and that will force the water out of the cylinder thru the spark plug hole.

Aternately, take a small hose that will fit into the spark plug hole, and tape it into the suction end of your shop vac hose and suck all the water ourt of the cylinder. I have to use this method to suck diesel out of the cylinders of my truck engine when I changed injectors and got diesel in all the cylinders.

Next, check your engine oil, power steering fluid, tilt/trim fluid, ect... for water. Change if necessarry.

Now, if the starter is dried out. Try and start the engine. It should fire right up. Idle it for a while to dry it out good.

Good luck on the starter still working. If it wasn't submerged long, maybe it is still good.

My main concern would be to get the water out of that cylinder and get it dried out before it rusts/corrodes.

Good Luck,

Mark

Posted: June 26 2008 at 09:28 | IP Logged

here is a link to a Mercruiser Service Bulletin on water intrusion, its causes and cures:

http://www.boatfix.com/merc/Bullet/01/01_13.pdf

This is a very good article with much information.

They reccommend using the starter motor to shoot the water out of the spark plug hole. I usually turn the moror over by hand a few times to clear the largest amount of water out, THEN I use the starter to spin it a few times to get as much out as I can. Then put the plugs in and fire it up.