Went to winterize........found some issues

[pwgsx]

Well I took the boat to the lake to warm up the engines to do a oil change. While the boat was idling on the trailer in the water I looked down to see smoke coming from the exhaust. I had some fogging oil burning off so it was very noticeable. Upon looking at it closer the smoke turned to steam. It was very hard to tell where exactly it was coming from but it didn't seem to be at the exhaust clamp and no water or anything was dripping. As far as I could tell it was coming from the flex area on the J- pipe. Is this coming for it to crack or leak?

Next I took it home and figured I would mess with the pipe in the spring so I continued to do all the winterizing. I started the motor and had the wife turn on the bilge pump with the antifreeze. About 1/3 left of 2 gallons the engine started to idle slower so I told her to stop the pump which she did. The engine ran for another 8 seconds or so where it idled even slower and died. I could not get the boat to re-start, finally after cranking and cranking it sputtered. Then it finally fired up and ran fine. This has never happened! I did the same to the other motor with no issues. I then went to change the plugs, the engine that died had plugs that looked very wet with fuel and black, not like burnt oil but like it got way too much gas while I was flushing with coolant and it flooded The other engine looked good.

 

[Floridan surfer]

Was the spark plug issue you had on the same engine with the leaky exhaust manifold? I had the same issue with a leaky exhaust manifold. I started a thread about it here:
http://www.seadooforum.com/showthread.php?t=69810

A watercraft mechanic told me that this leaky exhaust manifold forces water vapor into the engine after you shut it off, which fouls the spark plugs. I had that issue as well and I started a thread on it here:

http://www.seadooforum.com/showthread.php?t=67340

Basically what happened with me is in October last year (end of season) I had the spark plug issue. Because of the situation, that was my last boat outing of the season.
I fixed the spark plug issue over the winter months. Then spring came around, and the first time out, I discovered the leaky exhaust manifold. I didn't know that the two issues were linked at the time, but I learned that the leaky exhaust was apparently there before and caused the fouling of the spark plugs, after speaking with the aforementioned watercraft mechanic.

 

[Floridan surfer]

I just reread your post. It looks as though you were filling the exhaust with anti-freeze for winterization while the engine was running. My guess is that the leaky exhaust manifold allowed the anti-freeze to work it's way backwards and flood the engine. At Idle, there likely isn't enough back pressure to push the coolant through.

 

[pwgsx]

I just reread your post. It looks as though you were filling the exhaust with anti-freeze for winterization while the engine was running. My guess is that the leaky exhaust manifold allowed the anti-freeze to work it's way backwards and flood the engine. At Idle, there likely isn't enough back pressure to push the coolant through.

Makes sense but I didn't find any antifreeze in the engine oil at all. Perhaps it just got some water vapor in the combustion area and fouled the plugs? What is odd though is nothing was leaking into the hull at all, this has to be a very small leak on the J pipe, I wonder if its the flex area on the J pipe OR if I have a cracked manifold on the inside...... that wouldn't explain the steam escaping in the pic though. I had the manifold out last season and it looked great and I know that is a closed system and water leaves the manifold thru the 2 black hoses and they empty into the J pipe.