water leaking from plug

[BLACKBIRD2]

I had to replace my exhaust manifold, and exhaust flange,,i also changed my exhaust hoses some what,,the water is coming from plug the furthest back,or closest to the rear of the motor,its intermittent, if i close the raw water value a little it seems to control the H2O, that sometimes comes from the plug,is my water return for the exhaust to close to the exhaust flange,,or where the water exits the manifold,?

[edwardc]

I've seen this before. And although it looks like the water is coming from the plug, it's not. What happens is that a little trickle of water runs down the surface of the head, gets trapped in the depression around one of the spark plug holes, and starts boiling, giving the impression that it's bubbling out around the plug.

Now the trick is to figure out where the water is leaking from ( in my case, it was a cracked head ). Since you just messed with the manifold hoses and fittings, I would look there first.

[Al Schober]

I saw an engine with water boiling around a spark plug - it wasn't coming from the engine! There was a hose running over the engine that was dripping.
Find the source of the water then stop it.

[BLACKBIRD2]

plug water?

Gentleman, Thanks for the advice,,i pulled the plugs poured a little MMO, in the cylinders, turned the motor over a few times,i will check it out today,,

[JOHN COOKSON]

I had to replace my exhaust manifold, and exhaust flange,,i also changed my exhaust hoses some what,,the water is coming from plug the furthest back,or closest to the rear of the motor,its intermittent, if i close the raw water value a little it seems to control the H2O, that sometimes comes from the plug,is my water return for the exhaust to close to the exhaust flange,,or where the water exits the manifold,?

"is my water return for the exhaust to close to the exhaust flange or where the water exits the manifold?"

Don't quite understand what you are asking here. A picture is worth a thousand words.
Did you do the Thatch Modification when you rerouted the hoses?
Water can also leak from the thermostat housing and run down over the head and collect in a spark plug depression.
BTW the cylinder nearest the trany is #4 cylinder.
Welcome to the forum. Let us know where the water is coming from once you get it figured out.

TRUE GRIT

Edit: I think I get it now. Are you asking where the water where should the water be injected into the exhaust system after it leaves the manifold?

[BLACKBIRD2]

water entry into the exhaust

True Grit,,No water from thermostat ..all is well there,yes how far along the exhaust system should the return,be introduced, 5" to 8".and if it was to close could the water back up into the motor?,,im going out today,, i will be running the motor under load, i will see , if the MMO,, helped, Thanks

[roadnsky]

Here's a sketch with some instruction...

[JOHN COOKSON]

BB2
Did you rebuild the exhaust system from scratch? Or what?
If you have a "production" boat (rather than a custom built, one off boat design) let us know the make, length, and year built. There is a good chance someone in the forum has one like it and can give you some specific advice on how to construct the exhaust system. Also previous owners sometimes do modifications that are somewhat less than grand.
If none of this applies go with the guidelines from Jerry's post.

TRUE GRIT

[BunnyPlanet169]

BB2 - pictures are also extremely helpful!

[BLACKBIRD2]

Thanks

Jerry, thanks for the drawings, it looks like i need to move my return further away and closer to my water lift muffler,,john, i have a charley mogan, 38 1971, hull #68,,so most of what i do is trail and error, some days its mostly error,,,so i will rework,,what ive done,,Thanks again, This forum and its members are,awesome,

[edwardc]

Here's a link to a photo album of an actual exhaust rebuild to reference against the excellent drawing:

http://www.moyermarine.com/forums/album.php?albumid=73

[BLACKBIRD2]

ALLS WELL

i moved the return lower and further away,, its running as it should, pulled the water /oil mixture, new oil ,,all is good for now..thanks for the link Ed..

[Tim]

Did you ever find the source of the water leak? Where was the water around the plug coming from?

[BLACKBIRD2]

not yet

Tim,,i had to do another oil change,,which i knew,,it would take a couple of oil changes,to get the h20 out ,,but im thinking that by having my return for the water cooling,,line too close to my exhaust flange{exit}that water was backing up into the #4 cylinder,,,,also my run of piping was to level,,for to long ,,i needed to make a turn sooner,,so we shall see what shakes out,,,tomorrow after work,,,,

[Tim]

In the original post you said that water was leaking from around the #4 spark plug. How did the water get from inside cylinder #4 to outside spark plug #4? Was the spark plug corroded or somehow not seated very well?