Water in cylinders
 

Just curious what could cause water in the cylinders besides cracked head or block, bad head gasket or bad riser gasket?
https://cimg2.ibsrv.net/gimg/www.off...d907e7e87f.jpg
https://cimg3.ibsrv.net/gimg/www.off...fbde7d1bea.jpg

Cracked exhaust.

the gasket on #3 and #7 at the upper water hole looks a little suspicious, particularly #7. Almost looks like an old leak. Too much water pressure can cause a head gasket leak. Start simple and work your way there.

I assume you're talking about the circled part? #7 was definitely the worst.

https://cimg7.ibsrv.net/gimg/www.off...4f55c6de95.jpg

Number three doesnt look that great either and that is one of the cylinders with water in them. I was going to post a pic but i guess I am not allowed to :(

I am pretty sure they all had water in them. :( 3 and 5 were the worst because of piston position when I removed the head.
And I agree they all look like ****.

Yepper! That looks like it clearly leaked there. You should be careful after pulling that gasket that the block or head hasn't corroded at those spots.

Thanks. Will do. Going through the whole engine as the oil pressure dropped and when I cut the filter open it had the texture of gravy that got left in the fridge for 3 months,
Left the gasket on for now to get opinions.

#7 water to cylinder for sure. Between #5 and #7 cyl could have been letting a little combustion leak between themselves.

Also remember, a misfiring cylinder or two can suck water back like a 20yr old can beer on Thirsty Thursday on campus. :)

Factory heads or aftermarket ? Reason for asking, some aftermarket heads have wider combustion chambers and require a larger bore head gasket, even if larger than cyl bore.

Just curious ..... was that the Fel Pro marine gasket ? How many hours on it ?

Before you reassemble, have the mating surfaces properly decked (machined)..... in the meantime, you can check the mating surfaces with a straight edge and feeler gauges. If the surface is way out of wack, you can create leaks under the gaskets as proper crush specs can only do so much

Hey Scott, long time no talk. Factory 502 (088) heads.

By the looks of it I believe so. I just bought the boat this summer so I only know what I was told. Seller said the engines were rebuilt 50 hours ago but by the looks of things he lied.

Be sure to check the exhaust ports thoroughly on those 088 heads. You may need to have them pressure tested. They are known to rot where it is hard to see with naked eye. BTDT. Just another idea in the process of elimination. Good luck.

Thanks. I will have someone much more knowledgeable than myself going through the heads. :)

One other source of water that I encountered - ouch. The Merc belt-driven combo fuel pump/seawater pump can fail and water can be sucked from the failed fuel pump into the intake manifold through the vacuum line.

That is not a vacuum line. If there is a seal failure the fuel is supposed to be dumped into the intake.