water in cylinders

[Eyehooker]

2nd time had water in cylinders of OMC 4.3 V-6 I/O--last time put new flappers in engine-- engine is 2 years old ( Jasper Marine)--- this time the boat had been trolling for a long time very slow 1.5 - 2.0 -- water was not rough-- any thoughts-- compression OK

[Reel Boobs]

I am no expert, but how old are the risers and exhaust manifold? Maybe a little water is coming through a small leak in those or a bad gasket. Good luck and hopefully an expert will have better advice.

[Eyehooker]

This type of OMC is a one piece design riser and manifold-- they are orginal however the gaskets were replaced when the new engine was installed-- I was thinking about a small pin hole in the manifold and was trying to figure out how to pressure test-- just a thought-- never use in salt water

[baitkiller]

Eye hooker, the best way to tell if it is an exhaust problem is to strip and inspect. The manifolds come off pretty easy but are rather heavy. Be careful you don't snap off the spark plugs. I would remove them and look at the exhaust ports. If they are leaking you will see a clean trail from the water acting as a cleanser. We also used to just set them up on a bucket or block and run a garden hose in the fitting where water normally goes and watch the exhaust ports for water leaking out. Be aware that the intake manifold can also cause water intrusion and is susceptible to overheat damage.

[prockvoan]

Sounds like you do have a pin hole in the exhaust manifold.All it takes is a pin hole to push water into a cyl on the intake stroke!You can buy just one side to replace,but its just a matter of time the other will do the same.How old are they?Fresh water break them down too!Is the engine FWC?Replace them with a good set of Osco manifolds and risers.Cost around $400-$450.To help installing them,find a after market one piece exhaust gasket.It doesn't have to be marine to use it in that gasket.Have you pumped some engine oil into that cyl?If not do so now.If and when you pull that manifold off,bunp the engine till the piston is just about all the way up,shine a flashlight in the plug hole,see if you have any pitting on top of the piston if you don't want to pull the head.Water injustion normal just wipes out a piston top if it is just a little water at a time or bends the push rod were it wipes out the engine complety were it takes out that cyl and piston all together.You would of known if that happen at the time the engine quit running.Its not nice if the later happen.

Forgot,what baitkiller said about the clean trail will tell the tail.Good one Baitkiller!