F225 water in cylinder

[Hoxstriper]

I have twin 2004 Yamaha 225's on my boat with approx. 700 hours on them. After taking the boat out in November I flushed the engines and winterized. Last weekend I started servicing engines, plugs, oil, filters. On my starboard engine I took out the bottom right plug and a couple of teaspoons of water came out. The water was clear no rust or saltwater appearance. All other cylinders were clear on both engines.
So we start looking at that cylinder. Compression tests good and same as all others. We then pressure test to 100 lbs and all hold pressure, less than 3 lbs loss. Bore scope cylinder no apparent holes or issues to the eye.
Put lower unit back on and run on muffs for 20 minutes, purr's like a kitten as they always have. Check that plug cylinder, no water. Compression test at 180 warm, same as others. Engines runs great but still no idea about the water in that one cylinder. Plug was clean when first taken out, not fouled at all. Serviced with help of 20+ year marine tech. Knows his stuff.

Any ideas?????

DEan

[boats.net]

Start by checking exhaust inner cover for holes corroded through plate or bad gaskets.

[rwonsala]

Same issue

I was removing the plugs to change them for the season, and when I removed the bottom right plug I saw that it was wet. I turned over the motor with all plugs out and rusty water came out that one cylinder. Compression in all cylinders is 150 and the wet one is about 70. Any suggestions?