Water on Spark Plug

Zewbie

Cadet
Joined
May 24, 2010
Messages
22
I was out boating the other day and attempting to pull up new skiiers and did quite a bit of circling - take off, turn, slow down and cut the engine. During this I experienced a stall on take off and then a loss of power. After returning to the dock and inspecting things I found a water droplet on the rear spark plug. I checked the oil and it did not appear to have water in it. I haven't seen this before - I'm assuming it was pulled in through the exhaust, and hoping someone here might be able to shed some light on this situation. I dried the plug, put the boat on the muffs, started it and let it run for a while and didn't see any water on the plugs afterward. Was this a fluke thing? Do I possibly have a leaky seal or a hole developing somewhere? I would appreciate any insight into this.
Thanks in advance!
 

scrit9mm

Chief Petty Officer
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May 31, 2011
Messages
425
Re: Water on Spark Plug

I do not have any experience with that model engine, but I have the same outdrive. I ran into this problem right after I got my boat. Turns out there is no back-flow flapper in my exhaust to prevent water from coming through the risers and into the cylinder head. This has only happened when I shut off my motor when I am not "almost" stopped. Any forward momentum the boat has stops when you cut your engine off so the water is pushing on the back of the boat, that in turn forces water through the outdrive and into the cylinder head. My reasoning for this is there is no pressure sending out the exhaust through the outdrive so the water has nothing to stop it from coming in. Now I never shut off my engine until the wake has caught up to the back of the boat and the boat settles. I also never go from wide open throttle to idle, I gradually reduce the throttle until in neutral, or reduce it to idle then give it a little pump to help bring it down slowly. I have not had this problem since I changed my technique.

Again this is what happened to my boat, not yours. I would reccomend a thorough inspection if you are not handy in this matter.
 

dirtdog38

Seaman
Joined
Jun 29, 2011
Messages
53
Re: Water on Spark Plug

its rare u seen water on ther anyway if u had it running it gets burnt off to fast look at the plug if thers a crack to water it will be very clean looking no black at all. look at a plug guide if u need help
 

Zewbie

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May 24, 2010
Messages
22
Re: Water on Spark Plug

I did read some information online about water coming up through the risers. I'm hoping that's what it's from. The plugs look good and after drying the tip of the plug that had the water droplet and adding some fogging oil to the cylinders just to be safe it fired up and seemed to run fine. I'm planning on getting out in the next day or two to run it on the water.
Any other possibilities?
Thanks!
 

scrit9mm

Chief Petty Officer
Joined
May 31, 2011
Messages
425
Re: Water on Spark Plug

prevent hydrolock. only run just to temp then check all your spark plugs for water. repeat the next few times you go out. The little bit of time costs alot less than a new engine.
 

Zewbie

Cadet
Joined
May 24, 2010
Messages
22
Re: Water on Spark Plug

Well, I don't think this is good... I took it out and brought it up to temp, stopped and checked the plugs and they were all working without any sign of water on them. I did notice water in the bilge though and a wet spot toward the rear of the motor. Upon closer inspection it looked as if it were coming from the rear seal of the exhaust manifold. I cranked the motor and when I first hit the key some water and bubbles sprayed up out of the top middle of the manifold/gasket just next to the carb. Then when running it was leaking pretty good from the rear of the seal.

And, after closer inspection the oil seems like it might have some water in it too. Most posts I have read in regards to this the question comes up about freeze damage. I know it didn't freeze this past winter - it was definitely completely drained and in a heated garage. But when I started it on the muffs before heading to the lake this year rust colored water flushed out before it cleared.

What does this point to? Crack, seal, rust?

Thanks!
 

scrit9mm

Chief Petty Officer
Joined
May 31, 2011
Messages
425
Re: Water on Spark Plug

This is out of my knowledge. I hate to say it but it may be time to take it to a shop
 

Zewbie

Cadet
Joined
May 24, 2010
Messages
22
Re: Water on Spark Plug

Thanks for your input. A shop might be the answer, but I?m actually toying with the idea of pulling off the manifold to check it out. I guess at this point I?m wondering if there are things I should look for prior to opening it up.

Again?to summarize symptoms are?
Still starts/runs (but I?m not because I?m hoping to save it)
Water leaking from manifold seal
Water did appear on one spark plug
Water appears to have made its way into oil

And, based on what I?ve read and the above symptoms I believe possible culprits could be?
Manifold/Intake (crack, corrosion, and or seal)
Head (crack or seal)
Block (crack or seal)

If anyone else has any input I would appreciate it. THANKS!
 

tmfeaster

Petty Officer 3rd Class
Joined
Jun 22, 2011
Messages
94
Re: Water on Spark Plug

I don't know your setup but my engine is a bubble back and there is a exhaust cover over the exhaust manifold, two gaskets... one between the exhaust cover and exhaust manifold and the other between the exhaust manifold and the powerhead. The bubble back fills up with water, and of course the engine water pressure increases as you speed up.

I had an overheat and have been down the road of replacing the igition system, head gaskets, head cover gaskets and now the exhaust manifold gaskets... the exhaust manifold gaskets should be the last job before fixing her completely.

Mine seeped a little water out of the top and when at higher throttle, it came out faster and in more spots. When those gaskets blow you can get water in the cylinders, particularly the bottom cylidners (v4 in my case).

You need to inspect the cylinders and cylinder shafts to ensure there is no corrosion or rust from the water. I had a shop check mine just to be sure. If they are OK, replace your exhaust manifold gaskets and see where you are at after that.

I am not saying that is the fix, I am no expert but I figured I would chime in with my scenario and a few bits of information I have read from others.
 

Zewbie

Cadet
Joined
May 24, 2010
Messages
22
Re: Water on Spark Plug

I was planning on pressure testing the block however where my exhaust manifold is leaking it probably won't do me any good till that's replaced.

I changed the oil/filter and drained the water from the manifold (clogged with black sediment), block and hoses. I did a compression test cold - first dry then with oil (didn't want to start it) and the results of that were excellent. But, what was not good is that water sprays out of cylinder #1 even after the system was drained - residual I guess.

So, I know I have a bad seal between the manifold and head because I saw water spray from there. What are my options...
Do I take it somewhere and have them spend a bunch of time looking it over to tell me that I need a new engine?
Do I take it apart myself and see if I can figure out whether it's just two bad seals or a crack and corrosion?
Do I just assume that I need a new engine and order one and not spend the time looking any deeper?
Do I sell it as is and try to start over?
Or, are there other options?

Pretty bummed and just want to try and make the best decision here from both a financial and mechanical standpoint.

Thanks!
 

Zewbie

Cadet
Joined
May 24, 2010
Messages
22
Re: Water on Spark Plug

Update - I removed the manifold and head and they looked good. My manifold gasket was definitely shot and I found a piece of rubber blocking the hole in the head gasket of the #3 cylinder's water passage - can be seen in image. I am hoping this is what caused my issue and would like to know where it came from...hmm. I believe the water breached the head gasket there most of which ended up in cylinder #4 and some in #3.
New gaskets, reassemble and test...
 

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Smithclan

Recruit
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Jun 22, 2011
Messages
1
Re: Water on Spark Plug

Not sure whether this should be a new thread, or added to this one, because it looks as if you found your culpret, but here goes. I have a 1995 VP 3.0 with SX drive as well. I was out on the river and it got hot fast. I shut it down, but not before it got hotter than I would like. I pulled out the tools, and removed the raw water pump right then, the impeller was shot and swollen. The river here in florida is high in tanic acid and the rubber of the impeller was way swollen and the center hub was spinning in the outer rubber. I was towed in by a friend and replaced the impeller and thermostat later that day. All was well with the running temp, but I had a rough idle. After some close inspection I found a slightly wet plug on #4. Compression was 180 +/- 2lbs. on all four, so i ruled out the head gasket, at least for now. After being told by two mechanics and reading alot of posts about manifold cracks, I was afraid I was looking at a new 500.00 part. I hooked the garden hose to the front manifold inlet and rotated to exhaust stroke of #4 and sure enough, I had a very heavy stream of water pouring out the plug hole in no time. not having the funds for the manifold, i thought i would just start removing items and inspecting. I removed the exhaust elbow first and found that the restrictor plate gaskets were both leaking from the water jacket into the exhaust port. There was surface rust and gasket material separating on the narrow sealing surface. I cleaned all surfaces and took a wide flat file to both the manifold and the elbow to check for flatness, probably not the best way, but i am pretty steady with a file. Assembled, and I got really lucky. Everything was perfect, idled smooth as silk after it warmed up and the manifold was cleared of remaining water. After reading numerous post about water in #4 on this engine, I have not seen any that found this to be the issue, thought it might be worth your time.
 
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