water coming from spark plug 165hp

[flatliner1]

just noticed today after starting engine water driping out of spark plug #1.also it hard to start and backfired. 1974 165hp inboard please help

[tsubaki]

Flat I don't have an I/O but could you elaborate a little?
I assume it's either literally dripping out the plug hole or you got water droplets on the plugs electrode. Now if there is water on the tip of the plug with it in the head that's something else.
Just trying to clarify for the I/O guys.

[flatliner1]

well when i start engine after about 15 seconds a drip starts out of spark plug#1 im sure checked afew times thats the plug closest to the bow

[tsubaki]

When you say "out of". Help me here. In my entire life I have had one plug that the epoxy degraded and the porcelin came loose from the metal portion. Is the water literally comming out the plug? If so there is a head gasket leak and a damaged plug.

[flatliner1]

thanx i mean between the threads and the plug

[tsubaki]

There could be also water jacket problems between the block and head or the head could be eaten out and pouring coolant into the cylinder and the plug in damaged. I presume it's skipping?

[tsubaki]

Pull all the plugs and turn the motor over and pay attention to the cylinder in question and see if water (or water vapor) is comming out the plug hole. Be sure to have the water hooked up to it if it's drydocked.
If so there may be head damage or just a bad head gasket. Let one of the I/O guys confirm this, don't depend on me.

[tsubaki]

By the way, how long has the gas been in the tanks?

[tsubaki]

And if it is the head gasket. Food for thought. It may be possible to get a head gasket that is not marine grade. Only install the marine grade gasket. If there is another available it may be for an auto, the materials may not hold up to the salt water and leak prematurely.

[spareparts]

take a screw driver and poke the area around the spark plug, sounds like you have a water jacket rusting thru, there is a water passage right around the plug, been a whikle since I seen one like that, but it wouldn't be the first

[frayed_knot]

It is most likely your exhaust manifolds. They have a water jacket in them that will corrode and dump water into the cylinders. My bet is that is where the problem is. Take the manifold off and have a look.

[imported_admin]

Been there done that! Head has to be replaced!! Good Luck!

I changed it the first time, and I converted the 2nd time!!

[twistedparot]

boy, hope you werent lookin for an ez fix! good luck

[macojoe]

Mine was a 1975 so it was all the same you have. and the same plug!!

I was able to find a good car motor and used the head from that, I got the motor for $100, I ended up using the head and the oil pan.

Manfold went right after that!!

The second time it went was the #2 plug, don't know what happened, Gasket, rust, crack??

All I know was that it was going to be the last time!! I had it with that thing! Bracket and O/B and have never looked back! and it was easier to convert the monkey around with that motor all the time!

[tsubaki]

I'm more inclined to agree with frayed about the exhaust manifold being rotted and needing replaceing, it is the most likely culprit.
At least you got to take it off first to get to the head and gasket, you'll see then.

[axespino]

Where are you located? I have a spare motor from my 73 sitting in the barn and two lower units. One of the lower units is still in one boat and the other was rebuilt with not alot of time on it.

[cliffpaul2]

Flatliner didn't mention whether or not he had fresh water cooling. If so, does he need a marine head gasket?

[tsubaki]

Did they have them that year? I guess there is no reason not to.

[macojoe]

Raw water cooled!! all the old ones were unless someone added it later.

I have done this hole repair!! Head, then $500 for new manfold and riser, more cash for the gasket set, more for the exhust bellows that will surly be junk by the time he gets it off?

And the new manfolds come with new hose config to help with hot spots.

[flatliner1]

thanks for the help i brought my mechanic there and his diagnosis was a cracked piston head does tht sound about right.

[macojoe]

Sounds off to me?

Water doesn't get to the pistons that I know of?

Sounds more to me that the head gasket or the head rotted thur and dumped cold sea water on a hot pistion and cracked it?

Any how looks as though you going to need a new engin or a big rebuild!!

Every one has there opion but I say go bracket youg man, and never look back!

[tsubaki]

I'll stick with frayed about the exhaust manifold, then look at the head, if it is further than that trash the whole thing and do like MJ says and go bracket.

[76GMC1500]

Water doesn't get to the pistons that I know of?


I think he meant to say cracked cylinder head.

Sulzer RND's use water cooled pistons ;D

[flatliner1]

:Dsorry i meant to say a cracked cylinder head

[macojoe]

So whats the story?
What Happened??
What you doing to fix it??

Inquiring mines want to know!!

[flatliner1]

thanx joe the mechanic will be at the dock in the morning.the $$$ of learning ill be back on lake ontario soon if the diagnosis is correct.thank you for good posts.